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The Henryk Niewodniczański INSTITUTE OF NUCLEAR PHYSICS

Polish Academy of Sciences 152 Radzikowskiego str., 31-342 Kraków, Poland

www.ifj.edu.pl/reports/2005.html

Kraków, December 2005

Report No. 1969/AP

XXXVIII Polish Seminar on Nuclear Magnetic Resonance and Its Applications. Kraków, 1-2 December 2005

ABSTRACTS

Organizing Committee: K. Banaś S. Kwieciński

T. Banasik M. Labak A. Birczyński Z. T. Lalowicz J. Blicharski M. Noga /secretary/ J. Haduch K. Majcher S. Heinze-Paluchowska A. Mielczarek J. W. Hennel /chairman/ Z. Olejniczak A. Jasiński /v-chairman/ A. Szymocha A. Krzyżak T. Skórka P. Kulinowski

Sponsors:

AMX-ARMAR AG Bruker Polska Sp. z o.o Państwowa Agencja Atomistyki Varian International AG.

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Addresses of the sponsors:

AMX-ARMAR AG Anna Potrzebowska ul. Bułgarska 12a 93-362 Łódź tel. (042) 645 00 64 Bruker Polska Sp. z o.o ul. Budziszyńska 69 60-179 Poznań tel. (061) 868 90 08 fax. (061) 868 90 96 e-mail: [email protected] www.bruker.poznan.pl Państwowa Agencja Atomistyki Ul. Krucza 36, 00-921 Warszawa International AG mgr inŜ. W. Kośmider ul. Skarbka 21 60-348 Poznań tel. (061) 867 31 84 tel. kom. 602 287 918 e-mail: [email protected] www.varianinc.com

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CONTENTS:

NUCLEAR MAGNETIC DIPOLE MOMENTS FROM NMR SPECTRA – THEORY AND EXPERIMENT Andrej Antušek, Karol Jackowski, Michał Jaszuński, Włodzimierz Makulski, and Marcin Wilczek .…………………………………………………………………………… 9

MEASUREMENTS OF BOAR SPERMATOZOA MOTILITY USING PFG NMR METHOD Krzysztof Banaś, Tomasz Banasik, Dorota Wierzuchowska, and Andrzej Jasiński ………..… 10

DEUTERON NMR SPECTRA OF AMMONIUM ION ISOTOPOMERS AT LOW TEMPERATURES A. Birczyński, Zdzislaw T. Lalowicz, Z. Olejniczak, and G. Stoch ………………………….. 11

NMR RELAXATION IN PERIODICALLY PERTURBED SPIN SYSTEMS J.S. Blicharski and A. Bijak ………………………………………………………………….. 12

An NMR AND EXAFS STUDY OF CARBON ENCAPSULATED CO NANOPARTICLES Marta Borowiec, Mariusz Czapla, Marcin Sikora, Vit Prochazka, Dariusz A. Zając, Damian Rybicki, Czesław Kapusta, Clara Marquina, M.R. Ibarra, and Peter C. Riedi ……………….…………………………………………………………….. 13

MICROSTRUCTURAL ANALYSIS OF CARBONYL SIGNAL IN THE 13C NMR SPECTRA OF METHYL METHACRYLATE – n-BUTYL ACRYLATE COPOLYMER Piotr Bujak and Marek Matlengiewicz ………………………………………………………... 14

WHAT NUCLEAR SPINS TEACH US ABOUT MESOSCOPIC STRUCTURES AND THEIR CHANGE G. Buntkowsky ………………………………………………………....................................... 15

MEASUREMENT OF ALVEOLAR PARTIAL PRESSURE OF OXYGEN IN MICE USING 3He-MRI Katarzyna Cieślar, Hasan Alsaid, Vasile Stupar, Sophie Gaillard, Rachida Fissoune,

Emmanuelle Canet-Soulas, and Yannick Crémillieux …………............................................... 17

DAMPED QUANTUM ROTATION OF THE METHYL GROUP IN 9-METHYLTRIPTYCENE DERIVATIVES. THE MAGNITUDE OF THE EFFECT VS. THE ACTIVATION ENERGY Igor Czerski and Sławomir Szamański …………....................................................................... 19

IDENTIFICATION OF POLYHYDROXYLATED SPIROSTANES AND THEIR GLYCOSIDES FROM C.MAJALIS USING NMR TECHNIQUES Karolina. Dąbrowska- Balcerzak, Jadwiga Nartowska, and Iwona Wawel …………............... 20

DETERMINATION OF COMPLEX BINDING CONSTANTS AT NOT FAST ENOUGH CHEMICAL EXCHANGE Andrzej Ejchart …………........................................................................................................... 21

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SYMMETRY LOWERING in UPtSn: EVIDENCE FROM 119Sn AND 195Pt NMR STUDIES Agnieszka Grykałowska and Bogdan Nowak ………….......................................................... 22

DAMPED QUANTUM ROTATION IN SINGLE-CRYSTAL SPECTRA OF METHYLMALONIC ACID Peter Gutsche, Heike Schmitt, Ulrich Haeberlen, Tomasz Ratajczyk, and Sławomir Szymański ........................................................................................................... 24

DESIGN AND DEVELOPMENT OF THE GRAPHICAL USER INTERFACE (MR-GUI) FOR MRI SYSTEM BASED ON THE MARAN DRX CONSOLE. PRELIMINARY RESULTS Jerzy M. Haduch, Tomasz Banasik, Tomasz Skórka, and Andrzej Jasiński .............................. 25

PHASE TRANSITIONS AND MOLECULAR MOTIONS IN [Zn(NH3)4](ClO4)2 STUDIED BY QUASIELASTIC NEUTRON SCATTERING AND NUCLEAR MAGNETIC RESONANCE METHODS Łukasz Hetmańczyk, Anna Migdał-Mikuli, Edward Mikuli, Krystyna Hołderna-Natkaniec, and Ireneusz Natkaniec ............................................................. 27

INTERNAL DYNAMICS IN 6-FURFURYLAMINOPURINE STUDIED BY THE “ON”- AND “OFF-RESONANCE” 1H NMR Krystyna Holderna-Natkaniec, Kazimierz. Jurga, and Weronika Kasperkowiak ...................................................................................................... 39

AN EXPERIMENTAL TEST FOR THE APPROXIMATION OF NMR SOLVENT EFFECTS BY CONTINUUM MODELS. 19F GAS-TO-SOLUTION SHIFTS OF SF6 AND CF4 Karol Jackowski and Marcin Wilczek ........................................................................................ 31

MEASUREMENT OF MOISTURE TRANSPORT IN WOOD USING LOW FIELD 1D-MRI Sławomir Jakieła, Katarzyna Cieślar, Zbigniew Olejniczak, and Łukasz Bratasz ..................................................................................................................... 32

SEQUENCE-SPECIFIC ASSIGNMENT AND SECONDARY STRUCTURE OF THE CATALUTIC DOMAIN OF PROTEIN FROM UBIQUITINATION PATHWAY Łukasz Jaremko, Mariusz Jaremko, Renata Filipek, Roman Szczepanowski, Matthias Bochtler, and Igor Zhukov ................................................... 34

ADDUCTS OF AMINE WITH DIMERIC RHODIUM(II) TETRACARBOXYLATES - FORMATION OF NITROGENOUS CHIRAL CENTER Jarosław Jaźwiński ..................................................................................................................... 35

EFFICIENCY OF THE 1H → 31P NMR CROSS-POLARIZATION IN BONE AND SYNTHETIC APATITES Agnieszka Kaflak, Dariusz Chmielewski, Andrzej Górecki, Anna Slosarczyk, and Wacław Kołodziejski ............................................................................. 36

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A 55Mn NMR STUDY OF THE La0.75Sr0.25MnO3 NANOPARTICLES

Czesław Kapusta, Damian Rybicki, Marcin Sikora, Dariusz A. Zając, Zdenek Jirak, Karel Knizek, Miroslav Marysko, Emil Pollert, Pavel Veverka, and Peter C. Riedi ....................................................................................................................... 37

NUCLEAR SPIN RELAXATION STUDY OF MOLECULAR REORIENTATION OF 7-METHYLPURINE AND 9-METHYLPURINE IN CD3OD SOLUTION Dmytro Kotsyubynskyy and Adam Gryff-Keller ....................................................................... 38

NMR STUDY OF METHYLCITRIC ACID IN URINE PATIENTS SUFFERING FROM PROPIONIC ACIDEMIA Hanna Krawczyk and Wanda Gradowska .................................................................................. 39

ASSESSMENT OF SPINAL CORD INJURY OF A RAT ANALYSINGM ALTERATIONS OF THE WATER DIFFUSION TENSOR PARAMETERS Artur Tadeusz KrzyŜak and Andrzej Jasiński ............................................................................ 40 13C AND 1H NUCLEAR MAGNETIC SHIELDING AND SPIN-SPIN COUPLING CONSTANTS OF 13C-ENRICHED BROMOMETHANE IN THE GAS PHASE Marek Kubiszewski, Marcin Wilczek, and Karol Jackowski ..................................................... 42

CHANGES OF INTRACELLULAR INORGANIC PHOSPHATE IN RAT BRAIN AFTER INTRAVENOUS CDP-CHOLINE INJECTION - PRELIMINARY 31P MRS IN VIVO STUDY P. Kulinowski, M. Labak, K. Majcher, A. Herbik, P. Grieb, and A. Jasiński ............................ 43

APPLICATION OF 31P MRS TO EVALUATION OF CANCER PROLIFERATION Małgorzata Kuliszkiewicz-Janus, Mariusz Adam Tuz, and Stanisław Baczyński ..................... 45

ASSESSMENT OF METEABOLITE CONCENTRATION CHANGES IN RAT BRAIN FOLLOWING INTRAVENOUS CITICOLINE INJECTION USING MR SPECTROSCOPY IN VIVO M. Labak, P. Kulinowski, K. Majcher, M.A. Herbik, P. Grieb, and A. Jasiński ........................ 48

DOES EXIST A SMOOTH TRANSITION BETWEEN TUNNEL AND THERMALLY ACTIVATED DYNAMICS OF PROTON TRANSFER AS WELL METHYL HINDERED ROTATION? L. Latanowicz ............................................................................................................................. 50

THE GRID-ENABLED NMR SPECTROSCOPY Marcin Lawenda, Łukasz Popenda, Norbert Meyer, Maciej Stroiński, Zofia Gdaniec, and Ryszard W. Adamiak .................................................................................. 53

SIMULTANEOUS FUNCTIONAL MAGNETIC RESONANCE IMAGING OF THE RAT SPINAL CORD AND BRAIN K. Majcher, B. Tomanek, A. Jasinski, T. Foniok, P. W. Stroman, D. Kirk, U.I. Tuor, and G. Hess ....……….................................................................................. 54

DMTA AND “OFF RESONANCE-NMR” IN STUDY OF MOLECULAR DYNAMICS IN THERMOPLASTIC OLEFIN POLYMERS Monika Makrocka-Rydzyk, Grzegorz Nowaczyk, Aneta Woźniak-Braszak, Stanisław Głowinkowski, Kazimierz Jurga, and Stefan Jurga ................................................... 56

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AN 2H/1H ISOTOPE SHIFTS IN THE 1H NMR SPECTRA OF WATER IN GASEOUS ENVIRONMENT OF FLUOROMETHANES Włodzimierz Makulski ............................................................................................................... 58

THE SYNTHESIS AND NMR ANALYSIS OF THE THIAZOLIUM AND THIAZINIUM BETAINES Krzysztof Marciniec , Andrzej Maślankiewicz , and Maria J. Maślankiewicz .......................... 59

NMR STUDY OF ORDER-DISORDER PHENOMENA IN SOLIDS WITH STRUCTURAL PHASE TRANSITIONS Dieter Michel .............................................................................................................................. 62

AN ATTEPT TO TRACE NERVOUS FIBERS IN A RAT SPINAL CORD BY DTI Artur Mielczarek ...............................…...................................................................................... 63

THE INFLUENCE OF DRAWING ON MOLECULAR MOBILITY IN POLYPROPYLENE FIBERS Ľubomír Mucha, Jozef Murín, and Jana Kašovicová ................................................................ 64

NMR STUDY OF LOW DENSITY POLYETHYLENE FILLED WITH HIGH SURFACE AREA SILICA Jozef Murin, Ján Uhrin, Ladislav Horváth, Ladislav Ševčovič, Ľubomír Mucha, and Jozef Onufer ............................................................................................. 65

A CONFORMATIONAL STUDY OF SOME BENZOSUBERONE SYSTEMS BY USING GIAO/DFT NMR CALCULATIONS Ryszard Bolesław Nazarski ........................................................................................................ 67

EQUILIBRIUM CONSTANT DETERMINATION BY NMR. ADVANTAGES OF LINESHAPE ANALYSIS Michał Nowakowski, Andrzej Ejchart, Piotr Bernatowicz, and Helena Dodziuk ................................................................................................................... 68

ACTIVATION OVER A FLUCTUATING BARRIER: CALCULATION OF DIPOLAR CORRELATION FUNCTION Marcin Olszewski and N.A.Sergeev ........................................................................................... 69

COMPARATIVE EPR EXAMINATION OF GENTAMICIN, KANAMYCIN AND NETILMICIN EFFECTS ON FREE RADICALS IN DOPA-MELAN Barbara Pilawa, Ewa Buszman, Magdalena Zdybel, Dorota Wrześniok, and Aneta Grzegorczyk .............................................................................................................. 71

STRUCTURE OF SELECTED DERIVATES OF p-HYDROKSY CYNAMONIC ACID ACCORDING TO 13C CP MAS NMR AND DFT CALCULATION Dariusz Maciej Pisklak, Iwona Wawer, and Michał Tkaczyk .................................................. 73

STRUCTURE OF G-QUADRUPLEXES AND THEIR INTERACTIONS WITH CATIONS Janez Plavec ................................................................................................................................ 74

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CONFORMATIONAL CHANGES OF RNA DUPLEX INDUCED BY THE PRESENCE OF UNPAIRED ADENOSINE RESIDUE. NMR STUDY Łukasz Popenda and Zofia Gdaniec .......................................................................................... 75

NMR AND MOLECULAR DYNAMICS SIMULATIONS STUDY OF RNA BULGED DUPLEX Łukasz Popenda, Łukasz Bielecki, Zofia Gdaniec, and Ryszard W. Adamiak .......................... 76

SHAPE-SELECTIVE ISOMERIZATION OF 1,2,4-TRIMETHYL-BENZENE ON FERRIERITE-BASED CATALYSTS Rafał Rachwalik, Zbigniew Olejniczak, Jian Jiao, Michael Hunger, and Bogdan Sulikowski .............................................................................................................. 77

AN NMR STUDY OF LA2-2XSR1+2XMN2O7 BILAYERED MANGANITES

Damian Rybicki, Devashibhai T. Adroja, Colin J. Oates, Czesław Kapusta, Peter C. Riedi, Toby G. Perring, G. Balakrishnan, and Don McK. Pau ..................................... 80

DECAYS OF CARR-PURCELL ECHOES N.A.Sergeev, A.M.Panich, and M.Olszewski ............................................................................ 81

THE USE OF 1H-NMR SPECTROSCOPY IN CONTROLLING THE SYNTHESIS OF CLOPIDOGREL Maciej SkarŜyński, Bogdan Zagrodzki, Anna Bielejewska, Magdalena Glice, and Wioleta Maruszak ................................................................................... 84

THEORETICAL AND EXPERIMENTAL NMR PARAMETERS OF SUBSTITUTED PURINES Stanislav Standara, Kateřina Maliňáková, Zuzana Zacharová, Jaromír Toušek, Michal Hocek, and Radek Marek ..................….......................................…... 85

CONFORMATIONAL ANALYSIS OF BENZANNELATED NINE-MEMBERED RING LACTONES Anna Stankiewicz and Barbara Rys ........................................….......................................…... 86

NMR ANALYSIS OF RNA BULGED STRUCTURES: TABU SEARCH APPLICATION IN NOE SIGNAL ASSIGNMENT Marta Szachniuk, Łukasz Popenda, Zofia Gdaniec, Ryszard W. Adamiak, and Jacek BłaŜewicz ................................................................................................................... 87 1H NMR, 13C NMR AND COMPUTATIONAL DFT STUDY OF THE SOLUTION STRUCTURE OF 2-FORMYLCYCLOHEXANE-1,3-DIONE AND ITS ALKALI METAL SALTS Przemysław Szczeciński, Adam Gryff-Keller, and Sergey Molchanov ..................................... 88

THE STRUCTURE OF THE OXIDATION PRODUCTS OF IMATINIB STUDIED WITH 1H- AND 13C-NMR SPECTROSCOPY Wojciech Szczepek, Maciej SkarŜyński, Piotr Cmoch, Wojciech Łuniewski, and BoŜena Kosmacińska ........................................................................................................... 89

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MOBILITY OF D2 AND CD4 MOLECULES IN CAGES OF ZEOLITE NaY AS STUDIED BY DEUTERON NMR RELAXATION A.M. Szymocha, J.S. Blicharski, Z.T. Lalowicz, and A. Gutsze ..........................…................ 90

1H NMR STUDY OF INTERNAL DYNAMICS OF 4-AMINOPYRIDINIUM CATION UNDER HIGH HYDROSTATIC PRESSURE Jolanta Świergiel, Krystyna Hołderna-Natkaniec, Wojciech Medycki, and Ryszard Jakuba .................................................................................................................... 91

QUANTUM CHEMICAL CALCULATIONS OF 15N NMR CHEMICAL SHIFTS OF Pd AND Pt COMPLEXES WITH NITROGEN CONTAINING HETEROCZCLES Jaromír Toušek, Leszek Pazderski, and Radek Marek ............................................................... 93

CORRELATION OF DEUTERIUM MOBILITY WITH QUADRUPOLE COUPLING CONSTANTS FOR RUTHENIUM COMPLEXES – AN NMR STUDY Bernadeta Walaszek, Anna Adamczyk, Tal Pery, Karine Philippot, Bruno Chaudret, Hans-Heinrich Limbach, and Gerd Buntkowsky ............................................ 94 13C CPMAS NMR STUDIES OF ANTHOCYANIDINS AND THEIR GLUCOSIDES Michał Wolniak and Iwona Wawer ............................................................................................ 95

NMR AND XAS STUDY OF FE-MO DOUBLE PEROVSKITES Dariusz A. Zając, Czesław Kapusta, Marta Borowiec, Marcin Sikora, Clara Marquina, Javier Blasco, and Manuel R. Ibarra ..................................... 96

TEETH CARIES DECAY IN MR IMAGING Marta M. Tanasiewicz, Władysław P. Węglarz, Tomasz W. Kupka, and Andrzej Jasiński ................................................................................................................... 98

EPR STUDIES OF SPIN-LATTICE INTERACTIONS IN Cladosporium cladosporioides AND Cladosporium herbarum MELANINS Magdalena Zdybel, Sławomir Wilczyński, Teresa Witoszyńska, Beata Brotoń, Barbara Pilawa, and Ewa Buszmen .................................................................... 100

13C CP MAS NMR AND GIAO-CHF/DFT CALCULATIONS OF FLAVONOIDS: MORIN, TRICIN, GENISTEIN, FORMONONETIN AND 3,7-DIHYDROXYFLAVONE Agnieszka Zielińska and Katarzyna Paradowska ...................................................................... 103 13C CP MAS NMR AND GIAO DFT CALCULATIONS OF SELECTED β-adrenolytics Monika Zielińska, Dariusz Maciej Pisklak, and Jakub Konarski ............................................. 104

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NUCLEAR MAGNETIC DIPOLE MOMENTS FROM NMR SPECTRA – THEORY AND EXPERIMENT

Andrej Antušeka, Karol Jackowskib, Michał Jaszuńskia, Włodzimierz Makulski b,

and Marcin Wilczekb a) Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland b) Department of Chemistry, Warsaw University, Warsaw, Poland

Some of the standard literature values of nuclear magnetic dipole moments are based on old NMR experimental data. However, in the procedure used to extract the magnetic moments of bare nuclei from the NMR spectra of molecules the effects due to the shielding of nuclei by electrons have been treated in a very crude manner. What is needed to obtain a precise value of the nuclear dipole moment is an accurate absolute shielding scale - nowadays derived from state-of-the-art ab initio calculations for a small reference molecule - and the measured chemical shift for the nucleus of interest between the reference molecule and the sample. We present an analysis combining the relevant ab initio data and experimental NMR gas-phase results. The gas-phase shielding constants are particularly useful, since they permit a direct comparison of theory and experiment, eliminating all the problems related to intermolecular interactions. The improvements in nuclear magnetic dipole moments are most clearly demonstrated considering a relation between the shielding of different nuclei in different molecules. We have tested this relation applying the old and new values of the nuclear moments, and the shielding constants derived using the old values are meaningless. For instance, for σ(13C) in TMS we obtain 246.0 ppm, in contrast to the best present estimate, 186.44 ppm. Tracing the source of the problem we find that the magnetic moment of 13C, 0.7024118 µN, was derived from NMR of liquid CH3I. With the present-day values of σ(13C) and σ(1H) in CH3I we obtain for the magnetic moment of 13C 0.7023715 µN; combining our new experimental data for CH4 with literature or our own ab initio shielding constants we find 0.7023694 and 0.7023698 µN, respectively. The latter three values lead to σ(13C in TMS) in the range 186.3-189.3 ppm, in much better agreement with 186.44 ppm. We obtain similar improvements in consistency reconsidering the magnetic moments for many other nuclei, for example 13C, 14N, 15N, 17O, 19F, 31P and 33S [1]. Reference: [1] A. Antušek, K. Jackowski, M. Jaszuński, W. Makulski, and M. Wilczek. Chem. Phys. Lett., 411:111, 2005. e-mail: [email protected]

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MEASUREMENTS OF BOAR SPERMATOZOA MOTILITY USING PFG NMR METHOD

Krzysztof Banaś1, Tomasz Banasik1, Dorota Wierzuchowska2, and Andrzej Jasiński1,2

1H. Niewodniczański Institute of Nuclear Physics PAN, Kraków, Poland 2Pedagogical University, Kraków, Poland

The evaluation of spermatozoa motility, viability and morphology is an essential parameter in the examination of sperm quality and in the establishment of correlations between sperm quality and fertility. Until now, assessment of sperm quality has been based on subjective evaluation of parameters, such as motility and viability, and on objective parameters, such as semen concentration and morphology abnormalities. When subjective optical microscopic evaluation was used in humans and animals, variations of 30 to 60% have been reported in the estimation of the motility parameters of the same ejaculates. To overcome this variability, different systems have been proposed such as turbidimetry, laser-Doppler spectroscopy, and photometric methods. Other accurate techniques, such as flow cytometry, which allows the evaluation of concentration, and cellulose-acetate/nitrate filter measure only a single semen parameter. The more recent track semen analysis system, based on individual spermatozoon evaluation, offers an accurate calculation of different semen parameters. Although some interesting results have already been obtained, many questions remain, which have to be answered to allow for further development in veterinary medicine, clinical fertility settings, physiological, and toxicology research activities. Pulsed field gradient nuclear magnetic resonance (PFG NMR) techniques have been presented demonstrating the potential to study flow and transport processes in complex systems. By PFG NMR, the molecular displacement can be measured that occurs during a time interval ∆, between two consecutive magnetic field gradient pulses. In this poster we present the results of PFG-NMR obtained for a number of samples of boar spermatozoa with varying motility and discuss whether this method can be useful for fast and reliable spermatozoa motility evaluation.

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DEUTERON NMR SPECTRA OF AMMONIUM ION ISOTOPOMERS AT LOW TEMPERATURES

A. Birczyński, Zdzislaw T. Lalowicz, Z. Olejniczak, and G. Stoch

Institute of Nuclear Physics PAS, Krakow, Poland

Partially deuterated ammonium ions open a new field in studies of molecular mobility and crystal structure. Depending on the deuteration the sample contains NH4

+, NH3D+, NH2D2

+, NHD3

+ and ND4+ with relative abundances given by the binomial distribution of protons and

deuterons. All isotopomers with deuterons may contribute characteristic deuteron NMR spectra at low temperatures, particularly in the case of rotational tunnelling.

Diverse mobility of ND4+ ions was observed in the ordered phase. Deuteron NMR

spectroscopy provided evidence for a domain structure in the ordered phase below 148K in (ND4)2PtCl4. There are rigid ND4

+ ions in domains and reorienting as well as tunnelling in transition regions between them. Relaxation rates for the ions in domains and “domain walls” differ by almost four orders of magnitude. Features related to existence of ordered domains were observed also for (ND4)2TeCl6 and (ND4)2PbCl6.

The NH3D+ spectra supply unprecedented information about its diverse mobility as seen

by a single deuteron spin. Deuteron spectroscopy provides evidence for rigid deuterons and mobile ones performing limited jumps or jumps about a single C2 or C3 symmetry axis. Such dynamic states coexist in some samples with relative contributions changing on increasing temperature up to about 20K only as then motional narrowing appears. Phonon mediated incoherent tunnelling has to be considered.

We may get information about mobility of protons in NH3D+ ions from the single crystal

spectra of the deuteron. Cases when protons are rigid, undergoing rotational tunnelling or stochastic reorientation can be clearly recognized. The research project supported during 2003-2005 by the State Committee for Scientific Research (Poland) Grant No 2 P03B 10 24.

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NMR RELAXATION IN PERIODICALLY PERTURBED SPIN SYSTEMS

J.S. Blicharski and A. Bijak

M. Smoluchowski Institute of Physics, Jagellonian University, Kraków, Poland Abstract

The efective relaxation time T2e is calculated in the weak collision and strong collision approximations for a system of identical noclear spins, perturbed by periodic sequences of r.f. pulses, sample spinning and dipole-dipole and quadrupole interactions.

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An NMR AND EXAFS STUDY OF CARBON ENCAPSULATED CO NANOPARTICLES

Marta Borowiec1*, Mariusz Czapla1, Marcin Sikora1, Vit Prochazka1,2,

Dariusz A. Zając1, Damian Rybicki1, Czesław Kapusta1, Clara Marquina 3, M.R. Ibarra 3, and Peter C. Riedi4

1Department of Solid State Physics, Faculty of Physics & Applied Computer Science, AGH University of Science and Technology, Kraków, Poland 2Faculty of Mathematics and Physics, Charles University, Prague, Czech Republic 3Instituto de Ciencias de Materiales de Aragon, Universidad de Zaragoza, Spain 4School of Physics and Astronomy, University of St. Andrews, UK *Email: [email protected]

A combined NMR and EXAFS study of carbon encapsulated cobalt nanoparticles is presented. The materials have recently attracted a great deal of interest owing to their potential applications as magnetic nanomarkers in immunomagnetic techniques of cytometry, in cancer therapy and in NMR imaging. The samples were prepared by arc melting of metallic cobalt with a graphite electrode. Two kinds of samples have been measured: cobalt particles in the soot and in the electrode material.

59Co NMR spin-echo spectra and spin-spin relaxation times have been measured at 4.2 K, 77 K and room temperature with an automated, frequency swept spectrometer. For a comparison measurements on the cobalt sponge and on cobalt rod have also been carried out. The spectra of Co nanoparticles in soot show a dominant resonance line similar to that of Co sponge which is predominantly of the FCC type. Weak satellites at lower frequencies can be attributed to Co sites with 1, 2, 3 .. carbon atoms in the next environment. A small contribution from the HCP phase is also observed. A relatively high NMR enhancement factor, i.e. a high susceptibility at NMR frequencies, indicates that they are mostly multi domain.

The 59Co NMR spin-echo spectrum for cobalt in the material of graphite electrode is similar to that of Co rod, which indicates a HCP structure of nanoparticles. A relatively low NMR enhancement factor indicates that the particles are mostly single domain. EXAFS spectra of cobalt nanoparticles in soot have been measured at the Co K edge in transmission mode at room temperature. The analysis of the results has been carried out with FEFF program. A simulation of the experimental spectrum with EXAFS of HCP and FCC cobalt shows that the experimental spectrum is much better reproduced with a fit of FCC cobalt, which is consistent with the NMR data.

The results of the study shows that the Co nanoparticles in soot are predominantly of FCC

type and are magnetically multi domain, which indicates they relatively large size. Due to the

presence of domain walls they exhibit a large magnetic susceptibility at NMR frequencies. The

Co nanoparticles in the graphite electrode material exhibit mostly a HCP structure and small,

single domain grains revealing a low magnetic susceptibility at NMR frequencies.

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MICROSTRUCTURAL ANALYSIS OF CARBONYL SIGNAL IN THE 13C NMR SPECTRA OF METHYL METHACRYLATE – n-BUTYL

ACRYLATE COPOLYMER

Piotr Bujak 1 and Marek Matlengiewicz1,2 1 Department of Environmental Chemistry and Technology, Silesian University, Katowice, Poland 2 Institute of Coal Chemistry, Polish Academy of Sciences, Gliwice, Poland

Microstructural information on acrylic copolymers, i.e. distribution of the comonomers along the macromolecular chain and their stereochemical arrangement (tacticity) can be derived from 13C NMR, analyzing the splitting of their carbonyl signal. In the 100 MHz 13C NMR spectrum of poly(methyl methacrylate-co-n-butyl acrylate), PMMA-nBA, the carbonyl signal at 174-178,5 ppm is clearly split into the lines of configurational-compositional pentads. This splitting is slightly different in different solvents, hence, recording of the same sample in different solvents may reveal differences important to correct assignment of individual sequences, since their probabilities (intensities) remain the same, while the chemical shift can vary in different solvents. If we would like to perform a complete analysis at this level we have to determine the distribution of 272 individual pentads. The outermost lines in the carbonyl signal of the copolymer can be assigned to the sequences of pure composition by simple comparison with the spectra of respective homopolymers. The rest of the inner lines cannot be easily attributed, therefore, a series of copolymer samples of different composition were synthesized in order to observe the different heterosequences, since depending on copolymer composition, different signals representing individual sequences, assume different relative intensities. To confirm the correctness of proposed attribution a simulation of the carbonyl signal can be performed. It is therefore necessary to know the intensities and positions of individual signals, representing individual compositional-configurational pentads. Calculation of the intensity of the lines can be performed assuming Bernoullian and/or Markov statistics, separately for compositional and configurational sequences and verifying the overall distribution of the individual probabilities. The position of the individual lines cannot be straightforwardly determined, therefore, we have adopted an incremental method, already applied to a similar copolymer. In this approach the influences of neighboring units on the chemical shift of the carbonyl signal are considered as additive and a set of incremental parameters can be determined. The chemical shifts of individual pentads can be calculated in this way as a linear combination of respective increments. Having both intensities and chemical shifts of individual sequences the copolymer spectrum can be simulated at the pentad level.

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WHAT NUCLEAR SPINS TEACH US ABOUT MESOSCOPIC STRUCTURES AND THEIR CHANGE

G. Buntkowsky

Friedrich Schiller-Universität Jena, Physikalische Chemie, Jena, Germany

The characterization of the structure of molecules and their changes in solid phases is a very important spectroscopic task, and necessary for understanding their physicochemical and biological functions.

In the talk several examples of our recent work are presented. The first example is a dipolar solid state NMR study of the structure of methoxy carbonyl urea (MCU). MCU was discussed recently as a potential long time nitrogen fertilizer. We succeeded to determine the full configuration of polycrystalline methoxy carbonyl urea and to elucidate details of the crystal packing, employing Rotational Echo Double Resonance (REDOR) spectroscopy, employing differently isotope labeled samples. In the second example solid state NMR spectroscopy is employed for a study of the molecular conformation and arrangement of a fifteen residue fragment of the Alzheimer β-amyloid peptides. Here pH dependent changes in the molecular arrangement are found. In the case of a sample lyophilized at pH 7.4 sample an anti-parallel β-sheet arrangement of the molecular strands with an one residue shift is found.

Dynamical properties of guest molecules in mesoporous silica are investigated with 2H-solid state and 1H-MAS NMR spectroscopy. First the rotational dynamics of Benzene-d6 confined in the low-diameter hexagonal ordered cylindrical pores of mesoporous silica with different diameters is studied in the temperature range between 236 K and 19 K and compared to bulk benzene-d6. At all temperatures below the freezing point the spectra of benzene in the silica show the co-existence of several states with temperature dependent intensity ratios. From the pore volume and the filling factor the number of molecular layers on the inner glassy surfaces is determined as ca. 3-molecular layers of benzene.

Next the adsorption of water in mesoporous silica materials with different diameters is studied by 1H-MAS and static solid state NMR spectroscopy. Depending on the preparation technique and pore diameter interesting differences in the spectra are observed and discussed. At higher filling levels interesting differences between low- and high pore diameter silica are observed. This result is attributed to a different pore filling mechanism of the two silica materials. Finally the micro-phase behavior of a binary liquid in these silica materials is studied by a combination of various NMR techniques. The phase separation temperature of the mixture in the pore is slightly lower than in the bulk mixture of the same composition and is broadened over a temperature range. A qualitative model of the phase separation process in the pores is developed, which assumes a temperature dependent domain-like structure of the liquid below the phase transition temperature and a breakdown of these domains upon reaching the transition temperature.

References: (1) A.T. Petkova, G. Buntkowsky, F. Dyda, R.D. Leapman, W.-M. Yau, and R. Tycko, J. Mol. Bio., 335, 247–260, (2004); (2) Th. Emmler, S. Gieschler, H. H. Limbach, and G. Buntkowsky, J. Mol. Struct. 700, 29–38, (2004).

16

(3) S. Macholl, F. Börner, and G. Buntkowsky, Chemistry Eur. J., 10, 4808 – 4816, (2004); (4) E. Gedat, A. Schreiber , J. Albrecht, I. Shenderovich, G. Findenegg , H.-H. Limbach, and G. Buntkowsky, J. Phys. Chem. B106, 1977, (2002); (5) W. Masierak, Th. Emmler, E. Gedat, A. Schreiber, G. H. Findenegg, and G. Buntkowsky, J. Phys. Chem., B108, 18890-18896, (2004); (6) B. Grünberg, Th. Emmler, E. Gedat, G. Findenegg, H.H.Limbach, and G. Buntkowsky, Chemistry Eur. J., 10, 5689-5696, (2004); (7) A. Vyalikh, Th. Emmler, E. Gedat, I. Shenderovich, G. H. Findenegg, H.-H. Limbach, and G. Buntkowsky, Solid State NMR, accepted for publication (2005).

17

MEASUREMENT OF ALVEOLAR PARTIAL PRESSURE OF OXYGEN IN MICE USING 3He-MRI

Katarzyna Cieślar1, Hasan Alsaid2, Vasile Stupar2, Sophie Gaillard2,

Rachida Fissoune2, Emmanuelle Canet-Soulas2, and Yannick Crémillieux2

1Institute of Physics, Jagellonian University, Kraków, Poland 2Laboratoire de RMN, CNRS, Université Lyon1, Lyon, France INTRODUCTION

Partial pressure of oxygen (pO2) and its depletion rate characterizing oxygen consumption are important parameters in lung function assessment. During breath-hold oxygen removal from the lungs is exponential with time (1) and can be described by: pO2(t) = p0exp(-t/r), where p0 is the initial partial pressure of oxygen and r is the oxygen consumption time constant. All previous pO2 measurements both in animals as well as in human subjects (2) were restricted to short breath-hold periods when linear decrease of pO2 can be assumed. Among laboratory animals mice are very useful due to wide range of available genetic disease models. However, high metabolic rate of these animals results in very fast pO2 decrease making it desirable to study the oxygen decay dynamics without using the simplified model of linear decrease of pO2. In this work we present the first results of pO2 measurements in mice using this novel approach. To be able to follow rapid changes of pO2 fast spiral single-acquisition method with sliding window technique used for RF correction was exploited. SUBJECTS AND METHODS

The experiments were performed on a 2 T magnet. 3He was polarized using a home-built spin-exchange polarizer. Male mice from strain c57BL/6 were anaesthetized by intraperitoneal injection of sodium pentobarbital and tracheotomised. Pure 3He or mixtures of 3He and air (total volume of 0.8 ml) were administered through the endotracheal tube and imaging followed immediately. Spiral sequence with 12 interleaved spirals per image and 1024 samples/spiral was used (flip angle = 5 deg, TE = 2 ms, TR = 27.3 ms, FOV = 40mm). Series of 12 coronal or transverse projections were obtained with delay time of 527 ms between consecutive images. The first two images in each series were acquired without any delay between them and served to estimate the depolarization effect of RF excitation. Fig.1. Transverse projection of mice lungs. Fig.2. pO2 decay curves for [O2] of 6% and 11%.

18

RESULTS Fig 1 presents transverse projection of the lungs filled with mixture of 3He and air

resulting in estimated final oxygen concentration of about 11 %. A comparison of pO2 decay curves obtained from the measurements for [O2] = 6% and 11 % is shown figure 2. CONCLUSIONS

We have shown that it is possible to measure the initial partial pressure of oxygen as well as oxygen consumption time constant despite the fast nonlinear decay of pO2 in mice. The method can be used to study disturbances in ventilation and perfusion in mice models of various lung diseases. REFERENCES: 1. Lai Y-L, Hildebrandt J (1978) J. Appl. Physiol. 45(2): 255-260; 2. Deninger et al. (1999) J. Mag. Reson. 141: 207-216.

19

DAMPED QUANTUM ROTATION OF THE METHYL GROUP IN 9-METHYLTRIPTYCENE DERIVATIVES. THE MAGNITUDE

OF THE EFFECT VS. THE ACTIVATION ENERGY

Igor Czerski and Sławomir Szymański Institute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland

According to the damped quantum rotation (DQR) theory, hindered rotation of methyl qroups, reflected in NMR spectra, is a quantum mechanical process controlled by two quantum mechanical rate constants kt and kK. The subscripts t and K, designating “tunneling” and “Kramers”, refer to two specific, long-lived quantum coherences in the methyl rotor system each of which engages the space and spin coordinates of the three protons, correlated by the Pauli principle. Only in the instances where kt and kK happen to be equal, the NMR picture will be the same as for a hypothetical CH3 group undergoing classical jumps between its three equivalent orientations, described by single rate constant k’. Departure of the ratio c = kt / kK from 1 can thus serve as a quick measure of the degree of nonclassicality in the stochastic dynamics of the methyl group or, in other words, of the magnitude of the DQR effect. When the Arrhenius activation energy, Ea, for kK is about 12 kJmol-1, the nonclassicality factor c can exceed 5. This is an inference from our recent single-crystal NMR studies at temperatures 60 – 110 K [1]. On an intuitive ground, there should be an inverse (but hardly linear) correlation between Ea and c. Indeed, for strongly hindered methyl group in 9-methyltripticene derivatives for which the activation energies can exceed 37 kJmol-1, the DQR effect proves to be much smaller, with the corresponding values of c not exceeding 1.20 [2]. Nonetheless, for the values of c above 1.10 it can still be clearly seen in liquid-phase NMR spectra [3].

Here we report on our recent liquid-phase NMR experiments with a series of 9-methyltriptycene derivatives for which the values of Ea for kK span the range 37.4 - 44.8 kJmol-1 while the respective, average values of c vary between 1.04 and 1.20. It comes out that, within such a narrow variability range of Ea, the correlation between c and Ea no longer holds. For example, for 1,2,3,4-tetrabromo-9,10-dimethyltriptycene TBDMT the activation energy [42.1(4) kJmol-1] proves to be lower than for 1,4-dichloro-9,10-dimethyltriptycene DCDMT [for which Ea is 43.1(6) kJmol-1] while, contrary to expectations, the coefficient c for the former compound, 1.04(1), is significantly lower than for the latter [for which c is 1.14(1)]. It is still unclear what structural factors can control such fine details of the methyl group dynamics. A tentative answer is that in TBDMT the torsional motion of the methyl group is coupled to a nutation of the torsional axis more strongly than in DCDMT. Accordingly, the effective moment of inertia of the methyl group in the former compound will be larger than in the latter and, therefore, in TBDMT the relevant dynamics will more closely resemble the classical motion than in DCDMT. References: [1]. P. Gutsche, H. Schmitt, U. Haeberlen, T. Ratajczyk, and S. Szymański, Chem. Phys. Chem. 2005, submitted; [2] (a) P. Bernatowicz and S. Szymanski, Phys. Rev. Lett. 2002, 89, 023004; (b) I. Czerski, P. Bernatowicz, J. Jazwinski, and S. Szymanski, J. Chem. Phys. 2003, 118, 7157; [3] P. Bernatowicz, I. Czerski, J. Jazwinski, and S. Szymanski, J. Magn. Reson. 2004, 169, 284.

20

IDENTIFICATION OF POLYHYDROXYLATED SPIROSTANES AND THEIR GLYCOSIDES FROM C.MAJALIS USING NMR

TECHNIQUES

Karolina Dąbrowska- Balcerzak1, Jadwiga Nartowska2, and Iwona Wawer1

1Department of Physical Chemistry, 2Department of Pharmacognosy, Faculty of Pharmacy, The Medical University of Warsaw, Warsaw, Poland

C. majalis L. from the family Liliaceae is widely distributed in Europe whereas C. keisukei Miq. grows in East Asia. Convallasaponins with several OH groups were isolated from the flowers of C. keisukei [1] and from the roots and rhizomes of C. majalis [2, 3]. Polihydroxy steroidal saponins have been found in the family Liliaceae [4]. Our further investigation of the polar (n-BuOH / CHCl3) fraction of the extract from the roots and rhizomes of C. majalis has led to the isolation of new convallasaponins.

O

O

H

R1

OH

R2

R3

OH

O

O

H

R1

OH

R2

R3

OH

1 R1 = H R2 = OH R3 = OH

3 R1 = OH R2 = H R3 = OH

5 R1 = OH R2 = OH R3 = O-Galactose

7 R1 = OH R2 = OH R3 = O-Arabinose

5a R1 = OH R2 = OH R3 = OH

7a R1 = OH R2 = OH R3 = OH

2 R1 = H R2 = OH R3 = OH

4 R1 = OH R2 = H R3 = OH

6 R1 = OH R2 = OH R3 = O-Galactose

8 R1 = OH R2 = OH R3 = O-Arabinose

6a R1 = OH R2 = OH R3 = OH

8a R1 = OH R2 = OH R3 = OH The structures of the new saponins were deducted from 1H and 13C NMR spectral data and by interpretation of two-dimensional COSY, HMQC, HMBC and ROESY correlations. The new steroidal sapogenins are tetra- or pentaols with β - orientation of all hydroxy groups, as indicated on the figures. The 5-O – substitution of sugar moieties seemed to be rather unique.

21

DETERMINATION OF COMPLEX BINDING CONSTANTS AT NOT FAST ENOUGH CHEMICAL EXCHANGE

Andrzej Ejchart

Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warszawa, Poland Weak supramolecular complexes exist in solution at the equilibrium between free and complexed species. Almost always exchange between those states is fast in the NMR time scale. It means that one detects population averaged spectral parameters, usually chemical shifts owing to their easy determination: δobs = pbδb + pfδf [1] where δi are chemical shifts, whereas subscripts obs, b, and f correspond to the experimentally measured chemical shifts and chemical shifts in bound and free species, pb and pf are molar fractions of molecules in the bound and free states, respectively. The above given expression has been widely used for the determination of binding constants K in the NMR titration experiments (1). In such approach it is assumed that apparent chemical shifts δobs are free of systematic errors. Fast chemical exchange above the coalescence point, which is not fast enough, results in the nonlorentzian admixture to the signal lineshape (2). Moreover, the apparent signal maximum is not given by Eqn. [1] but shifted towards the chemical shift of the more populated component. Therefore, δobs < pbδb + pfδf for pf > pb and δobs > pbδb + pfδf for pf < pb. This effect always results in the underestimation of binding constant K and overestimation of the chemical shift in complexed state δb. Procedure, which allows one to avoid this systematic error, requires simultaneous determination of binding constant K, exchange rate k, and chemical shift in complexed state δb by fitting total signal lineshapes in a series of spectra obtained in the NMR titration experiment. References: (1) L. Fielding, Tetrahedron 56 (2000) 6151 – 6170; (2) J. Sandström, Dynamic NMR Spectroscopy, Academic Press, London, 1982.

22

SYMMETRY LOWERING in UPtSn: EVIDENCE FROM 119Sn AND 195Pt NMR STUDIES

Agnieszka Grykałowska and Bogdan Nowak

W. Trzebiatowski Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Wrocław, Poland The phase transition at T0 =35 K in UPtSn is peculiar, and the determination of the order parameter has been a longstanding issue for many years. At first, this transition was expected to have a magnetic origin, due to the specific heat behaviour [1.2] similar to that of the isoelectronic and isostructural antiferromagnet UNiSn (TN = 43 K). Also, theoretical calculations [3, 4] predict an antiferromagnetic ordering in UPtSn. However, no magnetic reflection has been observed in neutron diffraction experiment (Troć,André,2000, unpublished). In UNiSn the ordering is accompanied by a tetragonal distortion of the crystallographic unit cell and NMR signal of 119Sn disappears below TN. In UPtSn no departure from cubic symmetry below T0 was found in an x-ray experiment [2].

A major question in UPtSn is whether there is an internal structural distortion at T0. The NMR is a local probe which can provide intrinsic information. Therefore, the 119Sn and 195Pt NMR study were performed. We were particularly careful to explore the region near 35 K (see Fig.1) to search for signatures of the phase transition indicated by specific-heat experiment. The narrow, symmetric spectra shown (T>35K) have been obtained in the paramagnetic state. This indicate that there is no anisotropic NMR shift at both Sn and Pt sites, reflecting their cubic point symmetry above T0. On the other hand, the spectra recorded at T≤35 K reveal the powder-pattern line shapes characteristic for situation when a nucleus under investigation (119Sn or 195Pt) is in an environment of axial symmetry In both cases the spectrum below T0 gradually broadens with decreasing temperature In the normal state UPtSn crystallizes in the Mg-Ag-As type of structure with the cubic space group F-43m. Therefore, the observation of anisotropic lineshape of either 119Sn and 195Pt resonance gives microscopic evidence for the symmetry lowering below T0 in UPtSn although no such effect was observed in the x-ray diffraction experiment [2].

119Sn

Knight shift K [%]4.44.64.85.05.25.4

40K35K30K

195Pt

Knight shift K [%]-1.2-0.8-0.40.00.40.8

90K40K35K

Fig.1 Evolution of the frequency-sweep 119Sn and 195Pt NMR spectra in UPtSn around T0.

23

References: [1] T.T.M. Palstra et al., J. Appl. Phys. 63 (1988) 4279; [2] R. Troć et al., Philosophical Magazine 83 (2003)1235; [3] P.M. Oppeneer et al., Phys. Rev. B54 (1996) R3706; [4] J.A. Morkowski, A. Szajek, Czech. J. Phys., 54 (2004) D379.

24

DAMPED QUANTUM ROTATION IN SINGLE-CRYSTAL SPECTRA OF METHYLMALONIC ACID

Peter Gutschea, Heike Schmitta, Ulrich Haeberlena, Tomasz Ratajczykb,

and Sławomir Szymańskib

aMax-Planck Institute for Medical Research, Heidelberg, Germany bInstitute of Organic Chemistry, Polish Academy of Sciences, Warsaw, Poland

1H NMR spectra of the methyl group in an oriented crystal sample of methylmalonic acid with all three non-methyl protons replaced by deuterons are interpreted in terms of the damped quantum rotation (DQR) theory of NMR line shapes. The DQR approach offers a perfect theoretical reproduction of the observed spectra while the conventional Alexander-Binsch line shape model shows evident defects in the present case. The temperature trends of the quantities characterizing the coherent and incoherent dynamics of the methyl group in the DQR approach (the effective tunnelling frequency and two coherence-damping rates) derived from the spectra are fairly reproduced using a model reported previously.

The model involves 4 adjustable parameters: (i) the height V of a V(1-cos3ϕ)/2-shaped torsional potential of the methyl group; (ii) and (iii) the parameters fc and fs describing perturbations of the methyl rotor by its condensed environment acting as a quantum mechanical thermal bath and (iv) the “cut-off” frequency ωc of the bath, above which the density distribution of the bath oscillators rapidly approaches zero. The constants fc and fs (of the dimension of angular frequency) measure the displacements of the bath oscillators that result in the “breathing” (cosine-type) and “shaking” (sine-type) perturbations, respectively, of the torsional potential. The optimized values of the model parameters are: V = 1240 cm-1, fc/2πcl = 120 cm-1 (cl is the speed of light), fs/2πcl = 125 cm-1 and ωc/2πcl = 600 cm-1.

The present findings provide further evidence of limitations to the validity of the common belief that molecular rate processes in condensed phases are necessarily classical.

25

DESIGN AND DEVELOPMENT OF THE GRAPHICAL USER INTERFACE (MR-GUI) FOR MRI SYSTEM BASED ON THE MARA N

DRX CONSOLE. PRELIMINARY RESULTS

Jerzy M. Haduch1,2, Tomasz Banasik2, Tomasz Skórka2, and Andrzej Jasiński2

1AGH University of Science and Technology, Faculty of Physics and Applied Computer Science, Kraków, Poland 2The Henryk Niewodniczański Institute of Nuclear Physics PAN, Department of Magnetic Resonance, Kraków, Poland

Introduction Magnetic Resonance Imaging system based on MARAN DRX Console and 4,7 T superconducting magnet used in the Department of Magnetic Resonance at the Institute of Nuclear Physics PAN is equipped with the RINMR software by Resonance Instruments Ltd. It provides full control of the MR set and allows user access every parameter of the experiment. MR-GUI is designed to extend capabilities of the RIMNR software through suitable graphical user interface allows visualization of experiment results, to set data acquisition parameters and to design and execute examination protocol according to the GUI standards.

Aims Functional requirements for MR-GUI [2]: Functional requirements for MR-GUI [2]: • compatibility with existing libraries and usage of object files brought by MARAN DRX

Console controlled by RINMR – especially COM object brought by RINMR – and to overtake almost all functionality offered by the current system [1],

• usage of FFT and IFFT algorithms for reconstruction of the obtained MRI data, • communication with RINMR, via TCP/IP protocol, including: setting and getting experiment

parameters, loading and executing MR sequences • usage of the 2D sequences, • ability to visualize RINMR image and data files, • design of the examination protocol (list of the current examination sequence and sequences

being a reference to it) which can be saved and load with all of the examination parameters, • allowance to set number of slices and their field of view, visualization of the slice orientation

– setting slice orientation using previously done sequence as a reference image, • operating in MS WindowsTM 2000 and XP family OS’s, • to be written in object oriented environment which allows an easy implementation of

ActiveX/COM technologies and to allow further development of the created GUI.

Methods Methods and IT technologies used by MR-GUI [2]: • development using Borland Delphi 5.0 Professional environment, • consists of multiple units/modules which are easy to expand and to develop, • uses COM technology applied by Delphi to communicate via RINMR with MARANDRX

Console [1][4],

26

• uses Fastest Fourier Transform in The West algorithms obtained form the FFTW project website and adapted to magnetic resonance imaging purposes – usage of the fftw.dll library [4][5],

• uses OpenGL API for easy 2D visualization of data and for orientation of slices in 3D [3].

Preliminary results Developed software – MR-GUI (Fig. 1) fulfills all the functional requirements stated at the design level. It is expandable and allows user to use its own 2D MRI sequences depending on customizable, sequence-dependent libraries which needs to be created according to proposed template [2].

Fig. 1. MR-GUI screenshot. Slice selection according to reference images. [2]

At the current stage of development GUI operates on one sequence MSMED_TR written in the Department of Magnetic Resonance in the Institute of Nuclear Physics PAN, which is being used to verify MR-GUI. It is going to be tested on the MARAN DRX system to become fully operational and it is being developed to widen its capabilities in MRI.

Conclusions MR-GUI is being developed and upgraded. Future improvements will include cooperation with other sequences, which are being used by the Department of Magnetic Resonance. To widen GUI functionality also 3D sequences will be supported. Managing examination protocols and stored data will require designing some database system based, in example, on SQL-like databases. Creating GUI in Delphi environment allows to face with these demands.

References: 1. Guihéneuf T.: RINMR User Manual, Resonance Instruments Ltd 2002; 2. Haduch J.M.: Opracowanie przyjaznego, graficznego interfejsu uŜytkownika (GUI) do tomografu

magnetyczno-rezonansowego 4.7T opartego na systemie MARAN DRX, master of science project, not bublished, AGH, Cracow 2005;

3. Pokuta W.: OpenGL. Ćwiczenia, Helion, Gliwice 2003; 4. Pasławski A.: Programowanie w Delphi 5.0, Wydawnictwo „Edition 2000”, Kraków 2000; 5. http://www.fftw.org

27

PHASE TRANSITIONS AND MOLECULAR MOTIONS IN [Zn(NH 3)4](ClO 4)2 STUDIED BY QUASIELASTIC NEUTRON

SCATTERING AND NUCLEAR MAGNETIC RESONANCE METHODS

Łukasz Hetmańczyka, Anna Migdał-Mikuli a, Edward Mikuli a, Krystyna Hołderna-Natkaniecb, and Ireneusz Natkaniecc,d

a Jagellonian University, Faculty of Chemistry, Department of Chemical Physics, Kraków, Poland b A. Mickiewicz University, Institute of Physics, Poznań, Poland c Frank Laboratory of Neutron Physics, JINR, Dubna, Russia d H. Niewodniczański Institute of Nuclear Physics, Kraków , Poland Tetraamminezinc(II) chlorate(VII) with formula: [Zn(NH

3)4](ClO

4)2

is particularly

interesting molecular material because of the occurrence of reorientational motions of the

complex cations, as well as of the NH3 ligands and ClO

4

-

anions. In [Zn(NH3)4]2+

cation the Zn2+

ion occupies the center of a tetrahedron formed by the NH3

ligands. The ClO4

-

anions have also

a tetrahedral structure. The crystal structure of the title compound at room temperature is cubic,

space group m34For m3Fm__

(No 225 or 216) with lattice parameter a = 10.251 Å and Z = 4 [1]. On heating or on cooling this compound it undergoes two solid-solid phase transitions which are attributed to the changes in the molecular group’s arrangements as well as to the changes of their reorientational dynamics. The differential scanning calorimetry (DSC) measurements [2] performed in the temperature range of 90-300 K detected two anomalies of the heat flow connected with two phase transitions. The thermodynamic parameters of these phase transitions are presented in Table. 1

Table 1. Thermodynamics parameters of the phase transitions of [Zn(NH3)4](ClO4)2. TC1 = 273.5 K TC2 = 164.8 K

∆H1 = 0.45 J⋅mol-1 ∆H2 = 0.91 J⋅mol-1

∆S1 = 1.65 J⋅mol-1⋅K-1 ∆S2 = 5.52 J⋅mol-1⋅K-1

The measurements of the line width and of the second moment of 1

H NMR line were performed in the temperature range of 90-295 K on laboratory made instrument operating in the double modulation system. Figures 1a and 1b show the temperature dependencies of the second moment M2

1H NMR line and spin-lattice relaxation time T1 for the title compound. The observed value of the second moment of 1H NMR line for [Zn(NH3)4](ClO4)2 at 90 K is close to 9 G2 and can be interpreted as resulting from NH3 group reorientation about the three-fold symmetry axis of Zn-N bond of ligands. In the temperature range of 100–200 K the second moment value remains almost constant. At temperature T

C1 decreasing of the value of second

moment of NMR line was observed. The cation reorientation about the three fold symmetry axis

of tetrahedral [Zn(NH3)4]2+

cations was set on. No changes were found in the vicinity of TC2

phase transition temperature. Very similar behavior was observed in the case of [Zn(NH3)4](BF4)2 compound [3].

28

The spin-lattice relaxation time were performed by the saturation method with the pulse sequence n*π/2 -τ-π/2 at 30.MHz. The recovery of magnetization was one-exponential. However the minimum of function describing the relaxation rate versus temperature was not obtained, we estimated the energy activation for NH3 reorientation from left branch of experimental results. It is close to 0.8 kcal/mol in both phases. At phase transition TC2 the spin-lattice relaxation time T1 changing discontinuously. The neutron scattering (IINS, QENS) studies performed in the temperature range of 18–290 K

give also the evidence of fast (correlation time τ ≈ 10-11

– 10-12

s) stochastic reorientational motions of NH3 ligands in all of three phases of [Zn(NH

3)4](ClO

4)2.

3 4 5 6 7 8 9 101

10

100 150 200 250 300

6.5

7.0

7.5

8.0

8.5

9.0

TC1 T

C2

spin

-latti

ce r

elax

atio

n tim

e[s]

1000/T [K-1]

a)M

2(10

-8 T

2)

T [K]

[Zn(NH3)4](ClO

4)2

b)

TC1

TC2

Fig. 1. Temperature dependences: a) of the T1

obtained by 1

H NMR, b) of the second moment (M

2) for [Zn(NH

3)4](ClO

4)2 .

References: [1] H. Hillebrecht, G. Thiele, A. Koppenhöfer, and H. Vahrenkamp; Z. Naturforsch. 49b (1994) 1163; [2] A. Migdał-Mikuli, E. Mikuli, Ł. Hetmańczyk, E. Ściesińska, J. Ściesiński, S. Wróbel, and N. Górska, J. Mol. Struct. 596 (2001) 123; [3] A. Migdał-Mikuli, E. Mikuli, Ł. Hetmańczyk, I. Natkaniec, K. Hołderna-Natkaniec, and W. Łasocha, J. Solid St. Chem. 174 (2003) 357.

29

INTERNAL DYNAMICS IN 6-FURFURYLAMINOPURINE STUDIED BY THE “ON”- AND “OFF-RESONANCE” 1H NMR

Krystyna Holderna-Natkaniec, Kazimierz. Jurga, and Weronika Kasperkowiak

Institute of Physics Adam Mickiewicz University, Poznan, Poland

Natural cytokines are derivatives of a purine base –adenine – in which a molecular group (substituent) is attached to the C6 atom of the amine group. The object of the study was 6-Furfurylaminepurine. The molecules are bonded by two pairs of hydrogen bonds N-H…N, labelled as N9-H…N3 and N6-H…N7, of different lengths of 2.912 Å and 2.973 Å. The molecules form a ribbon of purine groups interconnected by hydrogen bonds and above as well as beyond the plane of the ribbon there are the furfuryl groups.

Temperature measurements of the spin-lattice relaxation time were made by the on-and off-resonance methods. The off-resonance NMR permits investigation of not only slow molecular motions described be spectral density function Jo(ωe) but also fast molecular motion described by the spectral density functions J(ω0) and J(2ω0). The latter are mainly studied by the on-resonance.

Fig. 1 presents the temperature dependencies of the spin-lattice relaxation time for the compound studied, obtained at 30 and 60 MHz. Thanks to the fact that the function T1=f(1/T) has a minimum, it was possible to determine the activation parameters of the furfuryl group reorientation on the basis of the on-resonance measurements [1], in which the relaxation process is observed in the laboratory frame.

3 6 9 12

6-Furfurylaminopurine

60 MHz

1

100

10

30 MHz

T1

[s]

1000/T [1/K]

Fig.1. Temperature dependence of spin-lattice ralaxation time of 6-furfurylaminopurine at 30 and 60 MHz.

Because two components of the resonance line were observed: a narrow and a broad one, we also applied the off-resonance method. In this method to a spin system in the thermodynamic

equilibrium a time-varying magnetic field 1B is

applied (ωe>> (ωL), of the angular velocity fπω 2= different from the resonance one ω0.

The effective field efB in the rotating frame is

described by the equation

iBkBBBBef

))

101 +

−=+=γω∆ . where

γ∆π

γω∆ f

BB2

0 =−= is the off-resonance

magnetic field. As a result of relaxation, the perpendicular component of magnetisation

decreases to zero ( 0→⊥M ) with a time

constant offT ρ2 . The magnetisation component

parallel to the effective field tends to the

30

efB

1B

0B

Z’

X’

B∆

θ

⊥M

M

0M

Fig.2. Rotation of magnetization around effective field in rotating frame.

equilibrium value 'M ρ , in this field

( 'MM ρ→

),with a time constant offT ρ1 . It

should be mentioned that the NMR off-resonance ( offT ρ1 ) method developed at the High

Pressure Laboratory at IF UAM , permits reaching maximum effective field of

410235 −⋅ T, for as long as 40 s with no sample overheating. The method permits the experimenter to change the frequency of the effective field ωef, flip angle θ and temperature. Assuming that the dominant mechanism of relaxation is the

dipolar interaction the rate of the spin-lattice relaxation is described by the equation proposed by Jonas [2] and Blicharski [3]. Taking some simplifying assumptions e.g. 10 >>cτω , ωe << ωo , θ

≤ 10o it was possible to determine two correlation times 31 10−≈cτ s and 8

2 10−≈cτ s on the basis of the magnetisation recovery measurements. These measurements were performed as

- a function of the effective frequency ωe at a constant angle θ =10° and a constant temperature,

- and then as a function of the fliping angle θ of the effective field from the constant magnetic field at a constant value of the effective field ωe=926.7 for 10 >>cτω , 1≈ceτω ,

1≈ieτω , 1<<ieτω at T=const.

The correlation time determined at a constant temperature by the off-resonance method was found to be in agreement with the results of the temperature studies performed by the on-resonance method. On the basis of the model proposed by Lipari and Szabo [4,5] it was possible to propose a model of internal dynamics of studied compounds. In particular, it was possible to take into account that in biologically active compounds in the solid phase an order parameter can be obtained, drawing conclusions enabling differentiation between the models of movement such as jumps among different sites or a wobbling motion, that can modify the bond conformation. The analysis of molecular dynamics can be performed for two processes characterised by different correlation times of an order of ms and ns.

References:

[1] Bloembergen N., Purcell E.M., and Pond R.V., Phys. Rev., 73, (1948) 679; [2] Jonas, Phys. Rev., 148, (1966) 312; [3] Blicharski J.S., ACTA Phys. Pol. , A41, (1972) 223; [4] Lipari J. and Szabo A., J. Am. Chem. Soc., 104, (1982) 4559; [5] Lipari J. and Szabo A., J. Am. Chem. Soc., 104, (1982) 4546.

31

AN EXPERIMENTAL TEST FOR THE APPROXIMATION OF NMR SOLVENT EFFECTS BY CONTINUUM MODELS.

19F GAS-TO-SOLUTION SHIFTS OF SF6 AND CF4

Karol Jackowski and Marcin Wilczek Laboratory of NMR Spectroscopy, Department of Chemistry, University of Warsaw, Warszawa, Poland

19F gas-to-solution shifts were measured for two solute molecules (SF6, CF4) and 39 organic solvents. A correlation between the results for SF6 and CF4 is satisfactory and proves that solvent effects can be described in the same way. The 19F shifts have also been compared with some previous gas-to-solution shifts observed for 129Xe gas and 33S in SF6. It is shown that intermolecular interactions change the shifts of external atoms (19F and 129Xe) in slightly different way than it is observed for the internal atom of 33S in a SF6 molecule.

32

MEASUREMENT OF MOISTURE TRANSPORT IN WOOD USING LOW FIELD 1D-MRI

Sławomir Jakieła1, Katarzyna Cieślar2, Zbigniew Olejniczak3, and Łukasz Bratasz1

1Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Kraków, Poland 2Institute of Physics, Jagellonian University, Kraków, Poland 3Institute of Nuclear Physics, Polish Academy of Sciences, Kraków, Poland

Historic old wooden structures are important part of European cultural heritage. They are sensitive to environmental damage, when exposed to the outdoor atmospheric conditions. Specifically, the damage in wood is caused by the attack of wood destroying fungi which develop under favourable moisture conditions. The purpose of this study was to characterize, by the MRI methods, the water transport in three species of wood that were used in the past as construction materials by builders and craftsmen in Europe. As the result a new, improved climate risk index could be introduced, which takes into account the actual moisture penetration depth and resulting actual infestation volumes of wooden structures. By combining the data with the long-term forecast of climate for a given area, it is possible to predict the extent of damage and undertake certain mitigation measures.

Specimens of oak, spruce and fir were prepared in a form of cylinders 8 cm high and 5 cm in diameter. Two specimens of each type of wood were used, the axis of the cylinder being either parallel or perpendicular to the principal anatomical directions of the wood fibers. The specimens were packed in a waterproof foil leaving only one end of the cylinder open to assure one-sided infiltration and drying. A watering system was constructed permitting a constant water flow into the specimens during ten consecutive days. The process of drying was monitored during the subsequent three weeks at 27 °C and 50% relative humidity. During both periods, mass of the specimens was also measured, with ±1 mg accuracy.

Monitoring of the spatial infiltration and drying was performed in a 0.009 T MRI system [1], using one-dimensional spin echo profiles (TE = 4.6 ms, TR = 3 s), with longitudinal resolution along z axis of 0.8 mm. The moisture content profiles were recorded every 1 hour during the first 12 hours of the infiltration/drying process and every 24 hours during the remaining part of

33

experiment. A typical set of one-dimensional profiles showing the dynamics of the drying process for spruce is shown in Fig.1.

A double permeability model was used to model the infiltration of water into wood [2]. The total moisture content θ is separated into two contributions α andβ , with the parametersηα,β describing the volume fractions of the α, β zones, respectively, characterized by different diffusion coefficients Dα,β. Thus, the total moisture content is given by the sum:

ββαα θηθηθ += . The double porosity model describes the transport of moisture by two coupled

equations which, in one dimensional case, are given by:

mD

mD

zzt

zzt

+=

−=

∂∂

∂∂

∂∂

∂∂

∂∂

∂∂

)(

)(ββ

αα

θββ

θβ

θαα

θα

ηη

ηη

where m is the exchange rate of water between two zones. All coefficients: αD , βD , αη , βη and

m were calculated from the spatial-temporal MRI profiles, taking into account the mass change of each specimen during the infiltration and drying processes. Typical experimental moisture graphs are computed in Fig.2. with the relationship fitted using above equations.

The data can be interpreted in terms of a very rapid transport through the vessels, with a

simultaneous diffusion in the denser material surrounding the vessels which is an order of magnitude slower. The model allows to simulate numerically the moisture penetration process in wood down to the 20% moisture content, which is critical for the fungal development. The consistency of the model for a given type of wood was evaluated by comparing the parameters obtained from two specimens cut differently, and for two different processes of watering and drying. The temperature dependence of diffusion coefficients will be determined from further experiments, which are in progress. References: 1. Suchanek M., Cieślar K., Pałasz T., Suchanek K., Dohnalik T., and Olejniczak Z., Acta Physica Polonica A 107, 491 (2005); 2. Krabbenhoft K., Damkilde L., Wood Sci. Technol. 38, 641 (2004).

34

SEQUENCE-SPECIFIC ASSIGNMENT AND SECONDARY STRUCTURE OF THE CATALUTIC DOMAIN OF PROTEIN

FROM UBIQUITINATION PATHWAY

Łukasz Jaremko1, Mariusz Jaremko1, Renata Filipek2, Roman Szczepanowski2, Matthias Bochtler2, and Igor Zhukov3

1Department of Chemistry, Wrocław University, Wrocław, Poland 2Institute of Molecular and Cell Biology, Warsaw, Poland 3of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland Ubiquitination is a post-translational protein modification which plays an important role in a wide variety of cellular processes including cell cycle, DNA repair and cell apoptosis. It is well known, that the ubiquitination requires sequential activity of three enzymes with different functions: activation, conjugation and ligation. Unfortunately, the three-dimensional structures of all three proteins responsible for these processes are not available at present and the process of proteins ubiquitination still is not understood in detail. In our communication, we present first, preliminary NMR data for the sequence-specific assignments for 112 amino acid residues long domain of one of the proteins from the

ubiquitination pathway. The NMR samples were prepared by dissolving 1 mM either 15N-

labeled or 15N,13C-double labeled protein in 90%/10% H2O/D2O, 50 mM TRIS buffer, and 50

mM NaCl. The pH was adjusted to 6.5 (uncorrected value). All NMR measurements were performed on the Varian Unity+ 500 NMR spectrometer (11.7 T) equipped with three channels,

Performa II PFG unit and 5 mm 1H, 13C, 15N-triple resonance probehead. The 1H, 15N, and 13C backbone resonances were assigned by standard methods using 3D heteronuclear HNCACB, CBCA(CO)NH, HNCA, HN(CO)CA, HNCO, (HCA)CO(CA)NH NMR spectra collected at

303K. The aliphatic 1H and 13C resonances were assigned on the basis of C(CO)NH, HBHA(CO)NH, and H(CO)NH experiments. After finishing of assignment procedure, solution of secondary structure in studied protein has been performed. The exact position of the α-helices and β-strands were solved on base analysis of cross-peaks between HN and Hα protons in 3D 15N-edited NOESY-HSQC spectrum, 3JNHα coupling constants evaluated from 3D HNHA

experiment, and chemical shifts of backbone nuclei (TALOS software). Obtained results will be used in future for solution of three-dimensional structure of catalytic domain with high resolution by means NMR methods.

35

ADDUCTS OF AMINE WITH DIMERIC RHODIUM(II) TETRACARBOXYLATES - FORMATION

OF NITROGENOUS CHIRAL CENTER

Jarosław Jaźwiński Institute of Organic Chemistry, Polish Academy of Sciences, Warszawa, Poland e-mail: [email protected]

Rhodium(II) tetracarboksylates Rh2(RCO2)4 (1a) are able to produce various complexes with organic ligands [1], like the 1:1 and 2:1 adducts containing axially bonded ligands (1b), or the compounds with rearranged dirhodium core (1c):

The solution of dirhodium(II) tetracarboxylate and a ligand usually contains a mixture of

adducts, due to ligand exchange and different equilibriums between species. However, application of nuclear magnetic resonance measurements at reduced temperature allows often observing the signals of all species in the solution. Ligands containing nitrogen atom were the subject of our previous investigation [2, 3]. It was found that dirhodium salts are able to form both 1:1 and 2:1 adducts with an amine, depending on reagents ratio. The present investigations are devoted to the amines with general formula NRR’R”, ie the amines having potential nitrogenous chiral center. An amine with three various substituents NRR’R” is formally a chiral molecule, but in the solution the molecule forms racemic mixture due to fast pyramidal inversion at the nitrogen atom. However, dirhodium(II) tetracarboxylates bonding the amine acts as an agent freezing pyramidal inversion at nitrogen atom, and results in formation of a new, nitrogenous chiral center in the adduct. Thus, the chiral dirhodium salt (4R)-Rh2[(CF3)(OCH3)(Ph)CO2]4 forms with benzyl-ethyl-methylamine five adducts: (4R)/(S), (4R)/(R) (1:1 adducts) and (R)/(4R)/(R), (R)/(4R)/(S), (S)/(4R)/(S) (2:1 adducts). All these diastereoisomers were detected by means of low temperature NMR (253 K). Similar effect was observed for the adducts with methyl-(1-phenyl-ethyl)-amine, PhCH(NHCH3)CH3, having both nitrogenous and carbon chiral centers.

References: [1] Cotton FA, Walton RA., Multiple Bond Between Metal Atom (2nd edn.) Claredon Press: Oxford, 1993 (chapter 7, pp. 431); [2]. Jaźwiński J. and Duddeck H., Magn. Reson. Chem., 41 (2003) 921; [3] Jaźwiński J., J. Mol. Struct., 750 (2005) 7.

This work was supported by the State Committee for Scientific Research under Grant No. 4 T09A 060 25.

36

EFFICIENCY OF THE 1H →→→→ 31P NMR CROSS-POLARIZATION IN BONE AND SYNTHETIC APATITES

Agnieszka Kaflak,1 Dariusz Chmielewski,2 Andrzej Górecki,2

Anna Slosarczyk,3 and Wacław Kołodziejski1 1 Medical University of Warsaw, Faculty of Pharmacy, Department of Inorganic and Analytical Chemistry, Warszawa, Poland 2 Medical University of Warsaw, Department of Orthopaedics, Warszawa, Poland 3 Stanislaw Staszic Univ. Min. & Met., Fac. Mat. Sci. & Ceram., Kraków, Poland

Human bone mineral was studied using solid-state 31P NMR with cross-polarization (CP) from protons. The CP efficiency was determined and discussed for trabecular and cortical bone tissue from adult subjects in comparison to synthetic mineral standards. The study proves similarity between CHA-B and bone mineral expressed by their similar CP behaviour. The method can be used for the characterization of synthetic apatite-based implant materials.

37

A 55Mn NMR STUDY OF THE La0.75Sr0.25MnO3 NANOPARTICLES

1Czesław Kapusta*, 1Damian Rybicki, 1Marcin Sikora, 1Dariusz A. Zając, 2Zdenek Jirak,

2Karel Knizek, 2Miroslav Marysko, 2Emil Pollert, 2Pavel Veverka, and 3Peter C. Riedi 1Department of Solid State Physics, Faculty of Physics & Applied Computer Science, AGH University of Science and Technology, Kraków, Poland 2Institute of Physics, Prague, Czech Republic 3Department of Physics & Astronomy, University of St. Andrews, Scotland, UK *Email: [email protected]

We report on a 55Mn NMR study of the La0.75Sr0.25MnO3 nanoparticles with the average grain size of 33nm and 114nm at 4.2K and at the applied field 0, 0.2 and 0.5T. A dominant signal from the double exchange (DE) controlled metallic ferromagnetic interior of the grains as well as a small signal from insulating ferromagnetic surface regions of the grains are observed. The DE resonant line shows a frequency shift in the applied field according to a full gyromagnetic ratio and a value of the demagnetizing field much smaller than 0.2T is obtained. In both samples studied a two-exponential nuclear spin-spin (T2) relaxation is observed at zero field, whereas a single-exponential relaxation is observed at the applied field of 0.5T. For the sample with larger grains a higher NMR enhancement is observed, which indicates a higher magnetic susceptibility of the sample at the NMR frequencies. A comparison to the NMR data obtained on a bulk material is made. The results are discussed in terms of the influence of the grain size and on the presence of domain walls or other magnetic inhomogeneities and on the magnetic anisotropy.

38

NUCLEAR SPIN RELAXATION STUDY OF MOLECULAR REORIENTATION OF 7-METHYLPURINE AND 9-METHYLPURINE

IN CD3OD SOLUTION

Dmytro Kotsyubynsky and Adam Gryff-Keller Faculty of Chemistry, Warsaw University of Technology, Warsaw, Poland Investigation of the kinetics of molecular movements in solutions can provide interesting information on intermolecular interactions, association, aggregation and related phenomena. One of the most efficient experimental methods of such investigations is based on interpretation of the nuclear spin relaxation rates. However, most of the literature relaxation studies assume isotropic or axially symmetric reorientation of the investigated molecules to avoid very complex mathematical description of the phenomenon. We decided to check the practicability of the interpretation procedure employing the symmetry of the rotational diffusion tensor being in full agreement with the molecular symmetry.

Fig. 7-methylpurine and 9-methylpurine. Keeping in mind a perspective of application of this method to study the behavior of nucleic bases and nucleosides in water solutions we have chosen as test examples 7-methylpurine and 9-methylpurine. The selected compounds seem to be especially suitable for testing purposes as these molecules are rigid, planar, and several independent relaxation data can be measured for them. Moreover, the size of these molecules guarantees the possibility of reliable theoretical calculation of all the necessary molecular parameters. In this communication the interpretation of the results of the relaxation measurements performed for the investigated purine derivatives will be presented.

N

N

N

N

1

2

3

4

5

6 7

8

9

N

N

N

N

1

2

3

4

56

7

8

9

39

NMR STUDY OF METHYLCITRIC ACID IN URINE PATIENTS SUFFERING FROM PROPIONIC ACIDEMIA

Hanna Krawczyk and Wanda Gradowska*

Faculty of Chemistry, Warsaw University of Technology, Warsaw, Poland, Email: [email protected] *The Children’s Memorial Health Institute, Warsaw, Poland

Methylcitric acid was synthesized in Reformatsky reaction 1 (2RS, 3RS diastereoisomers) and in nucleophilic addition 2 (2RS, 3SR diastereoisomers).

C2H5O

O

O

OC2H5

O

RO

O

Br

O

O C

Li

Zn

OTHF

C2H5O

O

O

OC2H5

O

A

B

C2H5O

O COOC2H5

OH

O

OR

C

C2H5O

O COOC2H5

OH

O

OC(CH3)3

H

H

CH2COOH

COOHH3C

HO

H

COOH

COOH

COOHH3C

HO

H

CH2COOH

CH3

HOOC

H

HOOC

HOOCCH2

OH

CH3

OHHOOC

HOOCCH2

H

HOOC

2

3

(2S,3S)

+

(2R,3R)

+

1 23

4

5

R = -C2H5;

R = -C(CH3)3

+

1.

2.

-78 C,

+1.

2. H3O1 2

3

4

5

+2

3

(2R,3S)

+

(2S,3R)

The stereoselectivity of these reactions was analysed. 1H and 13C NMR spectra of diastereoisomers of methylcitric acid were recorded and interpreted. The values of the 1H chemical shifts and 1H-1H coupling constants were analysed. Proton-decoupled high resolution 13C NMR spectra of MCA diastereoisomers were measured in a series of dilute water solutions of various acidity.

With regard to diagnostic applications, we used our preliminary results in analysis of MCA in propionic acidemia. 1H, 13C NMR and HSQC measurements were performed on samples of unprocessed urine of patients suffering from this diseases. Protons and carbons of MCA diastrereoisomers were identified. The relative concentration in investigated samples of the MCA diasteroisomers to the creatinine contents is for (2S, 3S) and for (2S, 3R) 0.174-0.198 and 0.203-0.300 respectively.

40

ASSESSMENT OF SPINAL CORD INJURY OF A RAT ANALYSING M ALTERATIONS OF THE WATER DIFFUSION TENSOR PARAMETE RS

Artur Tadeusz Krzy Ŝak1 and Andrzej Jasiński1,2

1Department of Magnetic Resonance, H. Niewodniczański Institute of Nuclear Physics, Kraków 2Department of Dielectrics and Biophysics, Pedagogical University, Kraków, Poland Introduction .

The spinal cord is the place of traumatic injury. So far, there is no effective repair method, mostly due to the great problems with composition of appropriate investigational model of such pathology. Diffusion tensor imaging (DTI) has the potential to evaluate the status of spinal cord after traumatic injury that is not evident on conventional Magnetic resonance imaging (MRI). Recent progress of MRI provides new possibilities to examine the central nervous system both in health and disease in vivo [1]. In this study, the estimation of evidence and extent of spinal cord injury using analysis of diffusion tensor parameters (DTP) is reported. Subjects and methods.

In vivo experiments were performed on 15 male Wistar rats on a 9.4 T/21 horizontal magnet. A conventional Spin-Echo imaging sequence with diffusion gradients was used to measure the effect of diffusion on MR images. The acquisition parameters were: image matrix= 128x256, FOV of 2 cm, TR = 2 s, TE = 40 ms, gradient b-factors up to 2000 mm2/s, slice thickness of 1 mm. Principal diffusivities (λ1, λ2, λ3) were determined after diagonalizing apparent diffusion tensor (ADT) for every pixel, next they were used for calculation following DTP:

longitudinal ADT� (DL) = λ3, transverse ADT┴ (DT) = (λ1+λ2)/2, isotropy index ID = ADT┴/ ADT�, trace Tr, and fractional anisotropy FA [2]. The following ROIs were examined: P - pyramidal tracts; DC(R, L) – Dorsal Column (Right, Left); DLC(R, L) – Dorso Lateral Column (Right, Left); VLC(R, L) – Ventro Lateral Column (Right, Left); VC(R, L) – Ventral Column (Right, Left); SG(R, L) – Substantia Gelatinosa (Right, Left); DH(R, L) – Dorsal Horn (Right, Left); VH(R, L) – Ventral Horn (Right, Left); CCR – Central Canal Region.

To examine differences between control and injured rats t-Student’s test (p < 0.05) was used for samples comparison. Results.

The figures 1 and 2 show the results of statistical analysis of DTP measured for control and injured rats in vivo. The significant statistical alteration of given parameter was assumed equal 1, no alteration 0.

41

The level of centre of injury

0 1 2 3 4 5

P

DCL

DLCL

VRCL

VCL

SGL

DHL

VHL

ID DL DT Tr FA

The level of 5mm rostrally

0 1 2 3 4 5

P

DCL

DLCL

VRCL

VCL

SGL

DHL

VHL

ID DL DT Tr FA

Conclusions. It was shown that investigation of DTP of the spinal cord can indicate statistically

(p<0.05) significant existence of injury. Our observation implies furthermore potential of this method to determine the extent of injury.

References. 1. Nevo U. et al, MRM (2001) 45:1-9; 2. KrzyŜak A.T. et al., ANE (2005) 65:255-264.

42

13C AND 1H NUCLEAR MAGNETIC SHIELDING AND SPIN-SPIN COUPLING CONSTANTS OF 13C-ENRICHED BROMOMETHANE

IN THE GAS PHASE

Marek Kubiszewski, Marcin Wilczek, and Karol Jackowski Laboratory of NMR Spectroscopy, Department of Chemistry, Warsaw University, Warszawa, Poland

13C and 1H NMR spectral parameters have been studied for 13C-enriched bromomethane (13CH3Br) in gaseous matrices. The solute compound was observed at low constant pressure (approx. 105 Torr) and the temperature of 300 K while sulfur hexafluoride (SF6) and carbon dioxide (CO2) were used as gaseous solvents. It was found that the 13C and 1H chemical shifts of 13CH3Br were linearly dependent on the solvent density. Similar dependence was also observed for the one-bond spin-spin coupling, 1J(CH). For the first time the 13C and 1H NMR parameters for an isolated 13CH3Br molecule were obtained, together with the coefficients responsible for the solute-solvent molecular interactions. The present experimental results confirm the extraordinary accuracy of some recent calculations of nuclear magnetic shielding performed for molecules containing heavy atoms.

43

CHANGES OF INTRACELLULAR INORGANIC PHOSPHATE IN RAT BRAIN AFTER INTRAVENOUS CDP-CHOLINE INJECTION -

PRELIMINARY 31P MRS IN VIVO STUDY

P. Kulinowski1,4, M. Labak1, K. Majcher1, A. Herbik2, P. Grieb2, and A. Jasiński1,3

1H. Niewodniczański Institute of Nuclear Physics PAS, Kraków, Poland 2M. Mossakowski Medical Research Centre PAS, Warszawa, Poland 3 Department of Dielectrical and Biophysics, Pedagogical University, Kraków, Poland 4 Department of Engineering, Pedagogical University, Kraków, Poland

Introduction:

Significant protection of CA1 neurones against delayed post-ischemic in small animals was reported by Grieb et al. [1] and Rao et al. [2]. Sato et al. [3] reported lack of protection of CA1 in the rat after intravenous injection of CDPCho. This study was designed to clear some aspects of thesis reported by Grieb et al. [1] using 31P MRS in vivo. The aim of study was to monitor concentrations of inorganic phosphate (Pi) after CDPCho administration. Methods:

The in vivo MR spectroscopic measurements were performed using 4.7T MR research system with Maran DRX console from Resonance Instruments and MR probe based on double-tuned (1H/31P) head surface coil. 31P MR signals were acquired with excitation-acquisition (FID) sequence with TR of 5s. Acquisition time was 9.5 min. for every 31P signal. Five different healthy male Wistar rats of body weight (250 - 280 g) were examined. The rats were cannulated immediately before the experiment. Solution of CDPCho was administered intravenously in three subsequent doses of 1 g/kg each, given every hour after starting MR signal acquisition. Anaesthesia was induced by chloral hydrate, and was maintained with a mixture of halothane with air and. Rats were maintained at 370C and ECG-breath monitored during the whole examination. The total duration of a complete examination was about 4 hours. Reference signal was acquired before any intravenous injection. Relative metabolite concentrations obtained from the signals following the first dose of CDPCho were compared to those obtained from reference signal. MR signal acquisition started 2 minutes after each subject was injected CDPCho and was repeated every 10 minutes. Time series of MR signals were analysed in time domain with jMRUI software package using AMARES procedure [4,5]. Estimated amplitudes of signal components were T1 corrected. Relative metabolite concentrations PCr/Pi, PCr/ATP and Pi/ATP were calculated. Statistical analysis were performed using non-parametric signed-rank Wilcoxon test with significance level of p<0.05. Metabolite ratios were compared between the measurements taken after each CDPCho injection and the reference. Results:

The PCr/Pi ratio decreased from 2.07±0.384 (reference) to 1.56±0.24 approximately about 30 minutes after first injection and to 1.33±0.18 after second injection of CDPCho. Pi/ATP increased from 0.389±0.076 (reference) to 0.515±0.074 approximately about 30 minutes after first injection and to 5.77±0.039 after second injection of CDPCho. PCr/Pi and Pi/ATP changes were statistically significant (p<0.05)

44

Conclusions: Changes of Pi in rat brain after intravenous CDPCho administration in doses of 1 g/kg

were detected using 31P MR spectroscopy. Obtained results should help to explain mechanisms underlying neuroprotective properties of CDPCho.

References: [1] Grieb P. et al., Folia Neuropathol, 39, 175-180 (2001); [2] Rao A.M. et al., Brain Res, 893: 268-272 (2001); [3] Sato H. et al., Biochem Biophys Res Comun, 150: 491-496; [4] Vanhamme L. et al., J Magn Reson, 129, 35-43 (1997); [5] Naressi A. et al., MAGMA, 12, 141-152 (2001).

45

APPLICATION OF 31P MRS TO EVALUATION OF CANCER PROLIFERATION

Małgorzata Kuliszkiewicz-Janus1, Mariusz Adam Tuz2, and Stanisław Baczyński3

1Dept. of Hematology and Transplantology, Wrocław Medical University, 2Institute of Experimental Physics, University of Wrocław, 3Faculty of Chemistry, University of Wrocław

The investigations of 31P spectra of sera and cells of patients with haematological malignancies (acute leukemia, malignant lymphoma, multiple myeloma) and other cancers: renal, thyroid, esophageal are a clinical trials over the introduction of MRS to monitoring of the therapy. Moreover the changes of concentrations of phospholipids in sera and cancer cells may explain their transport through cell membranes and significance of this mechanism in apoptosis.In plasma of healthy person phosphatidylcholine PC, sphingomyelin SM, lysophosphatidylcholine LPC and phosphatidylethanolamine PE prevail. PI and plasmalogens appear in plasma only in inconspicuous quantity. Cardiolipin (CL) is essential element of mitochondrial membranes. Sphingomyelin is the most known phospholipid in cancer disease as an important participant of signal trans-duction pathway. In our study the 31P spectra were obtained from: (a) sera, (b) sera with added the sodium salt of cholic acid (c) methanol-chloroform extracts of phospholipids from: plasma, peripheral blood mononuclear cells (PBMC), bone marrow mononuclear cells (BMMC). Cellular lipids were isolated from mononuclear cells Ficoll buffy coat centrifugation, and next underwent methanol-chlorophorm extraction. All spectra came from phospholipid extracts prepared from 60 x 106 cells.

In our preliminary studies we observed that 31P NMR spectra of normal serum consist of three peaks including a downfield peak due to Pi and two additional upfield field peaks from phospholipids PE + SM and PC. 31P spectra were performed in healthy volunteers, patients with acute leukemia, malignant lymphomas and multiple myeloma, at the time of diagnosis and repeated up to 13 times during chemotherapy The sodium salt of cholic acid added to serum caused separation of three phospholipid peaks located upfield from inorganic phosphate. Contrary to the earlier studies, peaks from PE+SM and PC, and also a peak from LPC were observed. The above mentioned separation method had also been applied in investigations of patients with digestive tract tumors and with renal cell carcinoma. Changes in phospholipids in the 31P NMR spectra observed in these patients were primarily dependent on the advance of the disease.

Long-term follow-up studies showed a good correlation between this 31P MRS evaluation of sera and the response of the disease to the therapy. At the time of diagnosis spectra showed strongly reduced peak areas and intensities from phospholipids (PC, LPC and PE + SM). During chemotherapy important changes in spectra were observed : (a) in responding patients the spectral profile changed to resemble that of normal serum with increased peak intensities, (b) in non-responding individuals peak intensities were reduced. Spectra of patients suffering from acute leukemia or HD, who have achieved com-plete remission for 4-12 years did not differ

from spectra of healthy volunteers.31P NMR spectra can prove the presence of the residual

leukemia in patients when the number of leukemic cells equals to 109 and is not detectable in

46

laboratory tests of the blood and bone marrow. 31P NMR spectra can depict the function of the transplantated.

In our study 31P MRS spectra of normal extract of serum consist of six peaks due to phospholipids. Beside previously identified, i.e. PC, LPC, PE and SM, some new ones were observed: PI, CPLAS. In patients with hematological cancers the values of peaks areas of PC, CPLAS, LPC, SM decreased. In some patients peaks from PI, PE were not observed. In responding patients the spectral profile changed to resemble that of normal extract. 31P MRS spectra of extract of mononuclear cells consist of 8 peaks due to phospholipids: PC, CPLAS, LPC, SM, PE, PI, PS, CL. The peak of LPC that has the most prognostic value in sera, in extract of mononuclear cells was observed only in some healthy volunteers. Important meaning for prognosis of disease course has got a presence of CPLAS. The values, considerably lower than those observed in healthy people have decidedly wrong prognostic value. However, patients with values considerably exceeding those existing in healthy volunteers quickly achieved remission of disease. These patients also have higher SM values than those non-responding to treatment, but lower than healthy volunteers. Identification of peaks was done in three steps: measurements of standard phospholipids (Sigma), measurements of the native phospholipids extracts with the standard phospholipids added, measurements of mixtures of all the standard phospholipids.

The experiences already achieved pointed out that 31P spectra at present didn't allow for diagnosis of haematological disorders, but were of great importance in monitoring of therapy of the diseases under consideration. Moreover, the changes of concentrations of phospholipids in sera and cells in haematological cancers are probably due to the increased uptake of phospholipid metabolites in proliferating blast cells, and their disturbed transport through cell membranes. The mechanism of transport of mentioned metabolites through cell membranes remains unknown and demands further studies. It seems that SM and CPLAS are of great importance in this process. Mechanism of changes of phospholipids concentrations in sera and cells in acute leukemia, as well as disturbed transport of phospholipids through cell membranes, remain unknown. It is very likely that observed reduction of the level of SM in blast cells’ extraction is due to activation of sphingomyelinase (SMnase) by tumor necrosis factor (TNF). SMnase cleaves SM, generating choline phosphate and ceramide. The latter – among other things – mediates programmed cell death (apoptosis), induces differentiation and inhibits growth of leukemia cells. As SM is an important participant of signal transduction pathway, the reason of reduced level of SM in the extracts of leukemia cells and changes concerning the CPLAS area need further investigation. It may be useful method for understanding the meaning of phospholipids in mechanism of cancer’s proliferation.

In this review of our study, it was shown how 31P MR spectroscopy can be applied for observations of changes of phospholipid concentrations in sera, plasma, PBMC and BMMC in patients with cancer diseases. This investigation points out that 31P MR spectra allow monitoring of phospholipid concentration in body fluid as well as in cells. Moreover, among acceptable various applications of 31P MRS, the possibility evaluating an advancement of disease, monitoring the treatment and forecasting resistance to the therapy seems to be the most promising. Simplicity of presented methods makes 31P MR spectroscopy a very useful tool for investigations of phospholipid metabolism.

47

References: 1. Kuliszkiewicz-Janus M, Baczyński S. J. Fraissard and O. Lapina (eds.),

Magnetic Resonance in Colloid and Interface Science, 347 – 354. 2002, Kluwer Academic Publishers. Printed in the Netherlands;

2. Kuliszkiewicz-Janus M, Baczyński S, Jurczyk A., Med. Sci. Monit 2004.10. CR 485-492;

3. Kuliszkiewicz-Janus M, Tuz M A, Baczyński S, Prajs I, and Jaźwiec B., Cell. Mol. Biol. Letters 2005,10, 377-388;

4. Kuliszkiewicz-Janus M, Tuz M.A and Baczynski S., Biochim. Biophys. Acta 2005.1737. 11-15;

5. Tuz MA, Kuliszkiewicz-Janus M, and Baczyński S., Pol. J. Chem. 2006 – in press.

48

ASSESSMENT OF METEABOLITE CONCENTRATION CHANGES IN RAT BRAIN FOLLOWING INTRAVENOUS CITICOLINE INJEC TION

USING MR SPECTROSCOPY IN VIVO

M. Labak1, P. Kulinowski1,3, K. Majcher1, M.A. Herbik 2, P. Grieb2, and A. Jasiński1,3

1H. Niewodniczański Institute of Nuclear Physics PAS, Kraków, Poland, 2M. Mossakowski Medical Research Centre PAS, Warszawa, Poland 3Pedagogical University, Kraków, Poland Introduction and Purpose

CDPcholine (citicoline, CDPCho) cytidine 5' diphosphate choline an essential precursor for the biosynthesis of phosphatidylcholine shows beneficial effects in various Central Nervous System (CNS) injury models and neurodegenerative diseases [1]. Previous studies demonstrate conflicting Magnetic Resonance Spectroscopy (MRS) reports regarding the impact of different choline-containing compounds, its doses and methods of administration on brain metabolites [2,3]. The main objective of our study was to assess the MR-visible metabolite concentration changes in the rat brain in vivo in response to three subsequent doses of citicoline given intravenously, using quantative 1H and 31P-MRS in vivo.

Methods and Materials

Subjects: Fourteen different healthy male Wistar rats of body weight (250 - 280 g) were examined using 1H and 31P-MRS in vivo. All animals were divided into three groups: six rats with CDPCho injection measured with 1H-MRS, four rats with CDPCho injection measured with 31P-MRS and four controls with saline injection measured with 1H-MRS. The rats were cannulated immediately before the experiment. Solution of CDPCho or saline, was administered intravenously in three subsequent doses of 1 gram/kg each, given every hour after starting MR signal acquisition. The animals were induced with chloral hydrate (500 mg/kg intraperitoneally), and anesthesia was maintained with a mixture of halothane (1.5%) with air (40%) and oxygen O2

(60%). Rats were maintained at 370C using water-circulating heating pad and monitored with rectal probe. All experiments were ECG and breath triggered.

In vivo NMR studies: The in vivo MR spectroscopic measurements were conducted at 4.7T MR research system with Maran DRX console (Resonance Instruments) using MR probe based on double-tuned head surface coil. Localized 1H MR signals from the whole brain were acquired with water suppression sequence based on spin-locking pulses [4] with TR/TE of 1s/200ms and number of accumulations of 512. Localized 31P MR signals were acquired with excitation-acquisition (FID) sequence with TR of 5s and number of accumulations of 114. The total duration of a single examination was about 4 hours. Time series of MR signals were analysed in time domain with jMRUI software package. Statistical analysis were performed using non-parametric signed-rank Wilcoxon test with significance level p<0.05.

Results and Discussion

1H-MRS cases: For six subjects injected citicoline in three subsequent doses of 1 gram/kg each, the statistically significant (p<0.05) increase of the Cho/Cr ratio after first and second dose of CDPCho were observed. Additionally, there was an increase of the Cho/NAA ratio after each

49

injection of citicoline, however this average changes were statistically not significant (p>0.05). The findings from group of four rats injected with saline in three subsequent doses of 0.25ml each, did not result in increase of Cho/Cr and Cho/NAA ratios after saline administration.

31P-MRS cases: 31P-MRS studies found noticeable change of PCr/Pi ratio in response to CDPCho. After performing 31P-MRS experiment with at least four subjects with saline injection, this study will be verified by the reference group. Conclusions

Our present study suggests that intravenous administration of CDPcholine does alter significantly the values of the main metabolites measured in vivo by means 1H MRS and 31P-MRS. References [1] Grieb P. et al., Folia Neuropathol., 39, 175-180 (2001); [2] Dechnet P. et al., Biol. Psychiatry, 46, 406-411 (1999); [3] Babb S.M. et al., Psychiatry Research: Neuroimaging, 130, 1-9 (2004); [4] Blondet P. et al., J. Mag. Res., 69, 403-409 (1986).

50

DOES EXIST A SMOOTH TRANSITION BETWEEN TUNNEL AND THERMALLY ACTIVATED DYNAMICS OF PROTON TRANSFER

AS WELL METHYL HINDERED ROTATION?

L. Latanowicz

Institute of Biotechnology and Environmental Sciences, Zielona Góra University, Monte Cassino Zielona Góra, Poland

A experimental demonstration of the smooth transition between quantum and classical dynamics, basis on the correction of the Arrhenius law for the temperature dependence of correlation time is presented in the last published paper [1]. Authors prove “finally and categorically” that the transition between quantum and classical regimes is a smooth and continuous and the spectral densities are characterised by a single correlation time. Above approach basis on the opinion written in referee rapports of our rejected papers “In that case the rate constants kov and ktu of the two processes, assumed to be independent, simply add and lead to one single inverse correlation time 1/τtotal = kov + ktu”. In the same way is prepared τtotal characterising methyl hindered rotation [2]. The differences between τtotal of proton jumps in hydrogen bond and methyl hindered rotation are in equations for ktu .

)1)/RTexp(/()1/RT)exp(-(kk tu0

tu −+= ∆∆ [3] or )RT/Eexp(-kk 01tu0

tu = [2] where ∆ is the

energy difference between minimums of double potential and E01 is the energy difference between ground and first excited torsional levels. Such assumed τtotal next is inserted into the equation for the spectral density of classical motion [4,5] (proton transfer dynamics) or [6] (methyl hindered rotation). The source of the success of single correlation time τtotal and concept (on the basis of this equation) of the smooth transition between the classical and tunneling regimes seems to be a consequence of the special character of the temperature dependence of τov and τtu . The τov is shorter at the high temperatures while τtu is shorter at low temperatures. The single correlation time which is shorter dominates in mechanism of the relaxation. But this approach has no theoretical support (see Fig. 6 in ref [7]).

The new approach to the NMR relaxation of solids containing tunnelling molecular groups (O-H…..O ↔ O….H-O, CX3 undergoing hindered rotation) is based on the fundamental corroboration of Woessner: “Although the two types of motion are independent, their contributions to relaxation are not. If the interaction Hamiltonian is modulated by series of independent stochastic processes, the total correlation function of a such complex motion should be calculated” [8]. Total spectral density of a complex motion consisting of Arrhenius-type jumps over the barrier and tunnel jumps through the barrier has been calculated in [9-13]. Proton jumps in hydrogen bond or in methyl group are characterised by two correlation times τov and τtu which characterises two fundamentally different motional processes - thermally activated jumps, over the barrier, and tunnelling jumps through the barrier. Classical jumps over the barrier are feature the whole molecular objects while the tunnelling jumps concerns the light atoms as hydrogen or deuteron jumping through the not too width barrier wall. Quantum mechanics involves the probability of tunnelling of the particle through the barrier, which is different in character and value than the probability of jumps over the barrier. The probability of tunnelling can be defined as D = I / I0, where I0 is the amplitude of the approaching wave and I is the amplitude of the wave that transmits through the barrier. The coefficient D depends on the value of the potential

51

barrier. For a rectangular barrier D = D0 exp{-2L/h[2m(U-E)]1/2}, where U and L are the height and the width of the barrier, E and m are the energy and mass of the particle. The temperature of cessation of the tunnelling jumps is expected from this solution. The value (U - E) under the square root is negative for E > U and the probability D is lost. The thermal energy of the Avogadro number of particles equals E = CpT [J/mol], where Cp is the molar heat capacity and T is temperature in the Kelvin scale. EH = NavU (in joules per mole) concerns the potential barrier of 1 mol of particles. Therefore, the temperature Ttun, calculated from the condition CpTtun = EH is the highest temperature of the higher than zero probability of tunnelling. The probability of tunnelling jumps defines through the barrier explicitly rate constant (1/τtu). New equation for the tunnelling correlation time derived on the basis of the Schrödinger equation has been proposed in [11-13]:

])Tp

Cov

(Eexp[-Btu0k

tu

1−=

τ where

AvN

2m2LB

h=

The mass of tunneling proton is m = 1.67 10-27 kg The barrier width L can be estimated on the basis of the structural data as L = 0.71 Ǻ for the distance between protons from two tautomeric forms (O-H….O ↔O…..H-O) or L = 1.78 Ǻ for H-H distance in methyl group. Therefore the

value of B is 0.101 1)J( − and 0.251 1)J( − respectively. The molar heat capacity Cp in solids is not the constant value. For example the temperature dependence of Cp [J/mol] given in ref. [14] for benzoic acid can be approximated by the equation:

)T/38exp(78)T/320exp(255Cp −+−=

The analysis of the results of field cycling NMR relaxometry given in paper [1] can be presented in term of Schrödinger equation: References: [1] W.Wu, D. L. Noble, and A. L. Horsewill, Chem. Phys. Lett. 402, 519 (2005); [2] A. J. Horsewill, Progress in NMR Spectroscopy 35, 359 (1999); [3] J. L. Skinner and H. P. Trommsdorff, J. Chem. Phys. 89, 897 (1988);

-2 -1 0 1 2

0,1

0,2

0,3

0,4

0,5

0,6

B (T)

T1-1

(s-1

)

BAC-h638.1 K[0.08]

0 10 20 30 40 50 60

10-11

10-10

10-9

10-8

10-7

10-6

10-5

BAC-h6

1000/T (K-1)

PR

OT

ON

CO

RR

ELA

TIO

N T

IME

(s)

#2#1

Fig. 1 The magnetic field dependence of T1 for BAC-h6 [1]. The solid lines are the fits to the theoretical expressions for complex motion, dashed lines - single classical motion, dotted lines - single tunnel motion.

Fig. 2 Correlation times τov and τtu for proton transfer in BAC-h6. Lines #1 and #2 represent the calculated correlation times using Arrhenius and Schrödinger equations. Points – the fit of experimental data [1]. Dotted line shows the fit of the Skinner and Trommsdorff correlation time ττυ

52

[4] S. Nagaoka, T. Terao, F. Imashiro, A. Saika, N. Hirota, and S. Hayashi, J. Chem. Phys. 79, 4694 (1983); [5] E. R. Andrew and L. Latanowicz, J. Magn. Reson. 68, (1986), 232; [6] D. E. O’Reilly andT. Tsang, Phys. Rev. 157, 417 (1967); [7] L. Latanowicz, E. C. Reynhardt, and J. Boguszynska J., Molec. Struct. (Teochem) 710, 111 (2004); [8] D. E Woessner, J. Chem. Phys. 36, 1 (1962); [9] E. C. Reynhardt and L. Latanowicz, J. Magn. Reson. 130, 195 (1998); [10] L. Latanowicz and E. C. Reynhardt, Chem. Phys. Lett. 341, 561 (2001); [11] L. Latanowicz, J. Phys. Chem. A108, 11172 (2004); [12] L. Latanowicz, W. Medycki, and R. Jakubas J. Phys. Chem. 109, 3097 (2005); [13] L. Latanowicz, Concepts Magn. Reson. Part A, 27A 38 (2005); [14] R. Sabbah, An Xu-wu, J. S. Chickos, M. L. Planas Leitão, M. V. Roux, and L. A. Torres, Thermochimica Acta 331 93, (1999).

53

THE GRID-ENABLED NMR SPECTROSCOPY

Marcin Lawenda1*, Łukasz Popenda2, Norbert Meyer1, Maciej Stroiński1, Zofia Gdaniec2, and Ryszard W. Adamiak2

1Poznań Supercomputing and Networking Center, Poznań, Poland 2Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland *Corresponding author: [email protected]

The laboratory equipment used for experimental work is very expensive and unique as well. Only big regional or national centers could afford to purchase and use it, but on a very limited scale. That is a real problem that disqualifies all other research groups not having direct access to these instruments. Therefore the proposed framework plays a crucial role in equalizing the chances of all research groups.

The Virtual Laboratory (VLab) project focuses its activity on embedding laboratory equipments in grid environments (handling HPC and visualization), touching some crucial issues not solved yet. In general the issues concern the standardization of the laboratory equipment definition to treat it as a simple grid resource, supporting the end user under the term of the workflow definition, introducing the accounting issues and prioritizing jobs which follow experiments on equipments. Nowadays, we have a lot of various equipments, which can be accessed remotely via network, but only on the way allowing the local management console/display to move through the network to make a simpler access. To manage an experimental and post-processing data as well as store them in a organized way, a special Digital Science Library was developed.

The project delivers a framework to enable the usage of many different scientific facilities. The physical layer of the architecture includes the existing high-speed network like PIONIER in Poland, and the HPC and visualization infrastructure. The application, in fact the framework, can be used in all experimental disciplines, where access to physical equipments are crucial, e.g., chemistry (spectrometer), radio astronomy (radio telescope), and medicine (CAT scanner). The poster presentation will show how we deployed the concept in chemistry, supporting these disciplines with grid environment and embedding the Bruker Avance 600 MHz and Varian 300 MHz spectrometers.

For more information please visit our webpage at: http://vlab.psnc.pl/.

54

SIMULTANEOUS FUNCTIONAL MAGNETIC RESONANCE IMAGING OF THE RAT SPINAL CORD AND BRAIN

K. Majcher 1, B. Tomanek2,3, A. Jasinski1, T. Foniok2, P. W. Stroman4, D. Kirk 3,

U. I. Tuor2,3, and G. Hess5

1Institute of Nuclear Physics, Polish Academy of Sciences, Kraków, Poland, 2Institute for Biodiagnostics, National Research Council of Canada, Calgary, Alberta, Canada, 3Dept of Neurosciences, University of Calgary, Experimental Imaging Centre, Calgary, Alberta, Canada, 4Dept of Diagnostic Radiology, Queen's University, Kingston, Ontario, Canada, 5Institute of Pharmacology, Polish Academy of Sciences and Jagiellonian University, Krakow, , Poland Introduction Functional MR Imaging (fMRI) of the brain has been widely used in the recent years [1] while spinal fMRI has been introduced for human studies in 2001 [2] and more recently for the study of animals [3]. There is a need for a non-invasive technique allowing observation of both brain and spinal neuronal activity elicited by the same stimulus, both for clinical assessment and for research of the Central Nervous System (CNS) function. Simultaneous brain and spinal fMRI is a non-invasive technique for the complete study of neuronal activity of the interconnected regions within the CNS. As indicated by electrophysiological data in the case of complete spinal cord injury, there may be instances where there is no activity elicited by a stimulus in the brain but does occur only caudal to a spinal cord injury, yet there is currently no tool to investigate this in vivo. Materials and Methods Animal preparation: Five Wistar rats were used. The animals were anesthetized with isoflurane. The rectal temperature was monitored and maintained at 37 ± 0.5°C. Animals were intubated and ventilated (ventilation volume 3-4 ml; BP: PO2 100-120 mm Hg, PCO2 35-45 mm Hg). Bupivacaine was administered into the cannulation wound site before closure. Anesthesia was gradually switched from isoflurane to ⟨-chloralose (30 mg/ml, 80 mg/kg) administered intravenously over approximately 20 min at the initial dose of 80 mg/kg and maintained at 20mg/kg, administered every 45 min. Following the completion of the imaging experiment, rats were immediately euthanasied with pentobarbital (120mg/kg, i.v.). Experimental setup: A 9.4T/21cm horizontal bore magnet was used. The animals were placed supine in the 5 ⋅ 7cm volume rf coil with the brain and cervical lower spine within the homogenous B1 field of the rf coil allowing slice positioning in the areas of expected neuronal activation. Experiment design: Functional images were acquired from the brain and spinal cord simultaneously using the same pulse sequence and the same imaging parameters in both regions. Two axial slices were positioned within the brain in somatosensory cortex and five axial slices within the spinal cord. A multislice, singleshot FSE sequence was used (TE =3ms, TEeff = 43.7ms, TR=7sec, FOV=2⋅2 cm, matrix size 64⋅64, 4 averages, slice th 2 mm, 0.5 mm gap in the spine and no gap in the brain). Data acquisition was gated with the respiratory cycle. Anatomical T2-weighted FSE images of the spinal cord were also acquired. Stimulation paradigm: The stimulation paradigm consisted of 31 time points with continuous 5 rest and stimulation periods (5 off – 6 on – 7 off - 7 on – 6 off). The total acquisition time of the one stimulation experiment was 14.4 min. Five stimulation experiments were performed with each animal with 5 min break period, allowing comparison of the

55

results between animals and between single stimulation experiments within the same animal. For electrical stimulation (6 mA, 0.3 ms pulse length, 3 Hz) two small needle electrodes were placed subcutaneously and taped. Results and Discussion Functional images of appropriate quality were obtained from four animals. The amplitude of changes in image intensity was approximately 3% and followed the stimulation paradigm (pδ0.001). Electrical stimulation of the forepaw resulted in consequent activation within gray matter of the spinal cord and somatosensory cortex in brain. The sites of activity were localized mainly in the dorsal horn of the spinal cord. An example of simultaneous spinal and brain fMRI obtained from one animal is shown (Fig. 1A-F) at the level of C8-C6, where transduced signal reaches gray matter neurons and then crosses the cord to the opposite side within the ventral horn. Neuronal activity was detected within the somatosensory cortex corresponding to the forelimb (S1FL), contralaterally to the stimulated forelimb, mainly in the slices positioned –1 mm from Bregma. The fMR images of the spinal cord were superimposed on anatomical images at five different levels of the cervical spinal cord corresponding to T2/T1, T1/C8, C7, C6 and C5 cervical levels (Fig. 1 A-E) respectively. The brain fMRI (Fig. 1F) shows an activation of the somatosensory cortex. The intensity changes of the activated voxels within either spinal cord follow the stimulation paradigm (p≤0.001) for each animal. These results demonstrate that the technique developed is able to assess simultaneously functional activation in the spinal cord and brain of the rat. This technique will provide a valuable tool to understand the interaction of functional pathways in normal conditions and the effects of injury and treatment.

Fig. 1. Neuronal activity in the rat spinal cord (A-E) and brain (F) obtained simultaneously from the single stimulation experiment. The spinal images are superimposed on anatomical images at five different levels of the cervical spinal cord: T2/T1, T1/C8, C7, C6 and C5 cervical levels from left to right (A-E) respectively. The ventral surface is at the top, dorsal surface at the bottom. The color used to indicate the active voxels corresponds to the level of the correlation to the paradigm: red corresponds to the highest, yellow -medium and green the lowest correlation coefficient respectively. References Bandettini P.A. et al, NMR Biomed 7, 12-20. 1994. 2. Stroman P.W. et al Concepts in Magnetic Resonance Part A, 16A(1): 28-34, 2003.3. Lawrence J, et al NeuroImage 22, 1802-1807, 2004. Acknowledgment: This work was supported by NATO Collaborative Linkage Grant No 979848.

56

DMTA AND “OFF RESONANCE-NMR” IN STUDY OF MOLECULAR DYNAMICS IN THERMOPLASTIC OLEFIN POLYMERS

Monika Makrocka-Rydzyk, Grzegorz Nowaczyk, Aneta Woźniak-Braszak*,

Stanisław Głowinkowski, Kazimierz Jurga*, and Stefan Jurga

Department of Macromolecular Physics, Institute of Physics, Adam Mickiewicz University, Poznań, Poland *Department of High Pressure Physics, Institute of Physics,Adam Mickiewicz University, Poznań, Poland

Dynamic-Mechanical Thermal Analysis and Nuclear Magnetic Resonance were employed

to study molecular dynamics of ethylene-norbornene copolymer. The materials used in this study were TOPAS copolymers (Thermoplastic Olefin Polymers of Amorphous Structure) made by Ticona, Germany [1]. These ethylene-norbornene copolymers of chemical structure as shown in scheme 1, belong to the class of technical termoplastics, which are easily processed materials. Due to their high glass transition temperatures combined with good chemical resistance and excellent optical transparency they have found a variety of optical applications. High moisture barrier effect, high strength and low density make them useful for packaging of medical and food products.

Scheme 1.

C

n

m

The analysis of experimental data confirmed existence of three motional processes denoted as α, β and γ in order of decreasing temperature, suggested from our previous studies [3]. The α relaxation is related to the dynamic glass transition, while the β-relaxation, observed only for the untreated sample, is assigned to short range segmental motions involving norbornene units [4]. The γ relaxation is due to local motions of ethylene units i.a. trans-gauche isomerization, similar to those responsible for γ-relaxation in polyethylene [5]. The motional parameters of processes, mentioned above, were derived from analysis of the temperature behavior of mechanical relaxation data and otherwise from analysis of the data of experiment at a single temperature using “off-resonance” NMR technique. References: [1] Lamonte R. R., D. McNally, Plastic Engineering 56, 51-59 (2000); [2] Mőlhaupt R., Macromol, Chem. Phys. 204, 289-327 (2003); [3] M. Makrocka-Rydzyk, B. Orozbaev, G. Nowaczyk,, S. Głowinkowski, and S. Jurga, Acta Phys. Pol. A108, 385-393 (2005)

57

[3] Chu P.P., Cheng M.-H., Huang W.-J., and Chang F.-C., Macromolecules 33, 9360-9366 (2000);

[4] Głowinkowski S., Makrocka-Rydzyk M., Wanke S., and Jurga S, Europ. Polym. J. 38, 961-969 (2002).

58

AN 2H/1H ISOTOPE SHIFTS IN THE 1H NMR SPECTRA OF WATER IN GASEOUS ENVIRONMENT

OF FLUOROMETHANES

Włodzimierz Makulski

Department of Chemistry, Warsaw University, Warsaw, Poland

In the present study the measurements of 1H chemical shifts in H216O and H16OD

molecules in gaseous mixtures with fluoromethanes are discussed. Over the range of accessible pressures of the gaseous buffer used the proton chemical shift vs. density of the medium relation is linear for either isotopomer and can be subjected to linear regression analysis. The analysis allowed to find the proton shielding constants in isolated HOH and HOD molecules at 300K. The isotope effect associated with this shielding, 2∆σ(2H,1H), was evaluated to be 0.0386 ppm and this value was compared with the available literature data. The new result for the isotope effect shows a better fit to the results obtained by the ab initio calculations [1], than the experimental data thus far known for liquid phase [2-4]. Obviously, for the strongly polar water molecules the interactions in liquids are very strong and significantly affect the 1H shielding parameters. Thus measurements in gaseous solutions proved expedient, with extrapolation of the results to a zero pressure. The effect of molecular interactions in the CFnH4n/HOH/HOD systems on the shielding of protons of water in the gaseous complexes formed were discussed. The spin-spin coupling 2J(2H,1H)= -1.06 Hz was measured experimentally in the partly deuterated water in gas phase for the first time. The adequate 2J(1H,1H) coupling constant in HOH found on this basis is -6.89 Hz.

2.80 2.602.70

Calculated

Experimental

δ [ppm]

Fig. 1. 500MHz 1H NMR spectrum of HOH/HOD in gaseous CH3F at 300K. References: [1] R.D. Wigglesworth, W.T. Raynes, S.P.A. Sauer, and J. Oddershede, Mol. Phys., 96, 1595 (1999); [2] R. Holmes, D. Kivelson,and W. C.Drinkard, J. Chem. Phys., 37, 150 (1962); [3] N.D. Sergeyeva, J.P. Jacobsen, and N.M. Sergeyev, Chem. Commun., 1355 (1998); [4] N.M. Sergeyev, N.D. Sergeyeva, Yu.A. Strelenko, and W.T.Raynes, Chem.Phys.Lett., 277, 142 (1997).

59

THE SYNTHESIS AND NMR ANALYSIS OF THE THIAZOLIUM AND THIAZINIUM BETAINES

Krzysztof Marciniec a), Andrzej Maślankiewicz a), and Maria J. Maślankiewicz b)

a) Department of Organic Chemistry, The Medical University of Silesia, Sosnowiec, Poland b) Institute of Chemistry, University of Silesia, Katowice, Poland

Electrochemically generated phenylsulfenyl cation reacts with 4-pentenoic acid to form 5-(phenylsulfanyl)methyloxolan-2-one1. The same reaction course was observed when 3,3’-bis(4-substituted quinolinyl)-, 4,4'-bis(3-, or 7-substituted quinolinyl)-disulfides and 3,3'-dipyridinyl disulfide were used as a source of azinylsulfenyl cation 12. Furthermore our study showed that in the case of 2,2'- and 8,8'- isomers of disulfides mentioned above the neighbour endocyclic nitrogen atom affects the reaction course and induces the cyclization of the reaction mixture components to 3-(2,3-dihydro-thiazolo [3,2-a]pyridinio-2-yl)propanoate 5, 3-(2,3-dihydro-thiazolo [3,2-a]quinolinio-2-yl)propanoate 6 and 3-(2,3-dihydro-1,4-thiazine [2,3,4-i,j]quinolinio-2-yl)propanoate 9 (scheme 1).

Scheme 1

2Azinyl SCH2O

98

7

5,63,4

O

N

S CH2

N

SCH

CH2

CH2CH2CO2

-H

route a

-H

route b

b

a

N

SCH2CH

CH2

CH2C

OH

O

N S

CH2 CH(CH2)2CO2

route b

-H

N SCH(CH2)2CO2H

CH2

2

1 CH2 CH(CH2)2CO2H

route a

-2H2Azinyl S

CH

CH2

CH2 CH2C OH

O

2Azinyl-SBu4NBrCH2Cl2

-2e(Azinyl-S-)2

60

If the sulfenylation of alkenes follows the Markovnikov rule 1, the reactions with α,α'-diazinyl disulfides and 8,8’-diquinolinyl disulfide should give products with S-CH2 groups 10 and 11. However, the δH values of S-CH and N+-CH2 protons in 1H NMR spectra of our products 5 and 6 fit well the respective data previously reported 3 for isomeric salt 12 (sche-me 2).

Scheme 2 The values of δH [ppm] for protons from S- and N-methylene or methine groups

in salts 5 and 6.

N

CH2 CHCH2Br

S

Br

5.20 4.76

Br

6.01 3.80

N

CH2 CH(CH2)2COO

S

4.41 5.07and 5.17

5

OOC(CH2)2CH

N

CH2

S

BrCH2CH

10,11

12 13

6

5.39

4.39CH2

SN N

CH2 CH(CH2)2COO

S

To prove this supposition a total analysis of the 1H and 13C NMR spectra of products 5, 6 and 9 were performed using 1D and 2D NMR techniques (including HSQC and HMBC). The crucial data in the structure assignment of 5, 6 and 9 come from the long-range proton-carbon correlations deduced from HMBC spectra. They show the connectivity links between N-methylene protons and both α-azinyl carbons as well as S-CH protons and Carom.-S carbons (scheme 3).

Scheme 3 Selected three-bond proton-carbon correlations deduced from HMBC spectra of 5 , 6 and 9

R = (CH2)2CO2

RR CH2

N S

CHHH

CH

CR

N

S CH2

9

S

CHH2C

NN

H2C CH

SH

5 6Non-identical δH values but the sameproton-carbon correlation were obser-ved for both bolded H atoms from N-CH2 groups of betaines 5 and 9.

Due to the folded shape of the dihydrothiazole and dihydrothiazine moiety in compounds

5 and 9, respectively, two signals of C-H protons (from N-CH2 groups) were observed. However, they exhibited the same one-bond and long-range proton carbon correlation.

61

References: 1. S. Töteberg-Kaulen and E. Steckhan, Tetrahedron, 1988, 44, 4389; 2. K. Marciniec, A. Maślankiewicz, and S. Boryczka, Heterocycles, 2002, 57, 1279; 3. D. G. Kim, Khim. Geterotsikl. Soedin., 1999, 35, 334.

62

NMR STUDY OF ORDER-DISORDER PHENOMENA IN SOLIDS WITH STRUCTURAL PHASE TRANSITIONS

Dieter Michel

Universität in Leipzig, Fakultät für Physik und Geowissenschaften Institut für Experimentale Physik II, Leipzig, Germany After a short introduction into the general possibilities for NMR studies in this context, I shall treat three examples which are parts of our research in this field. The studies comprise at first the properties of hydrogen-bonded solids. As typical systems, the proton ordering and proton dynamics in squaric acid and solids of the betaine family will be studied. In a second example, I will explain, how NMR may contribute to the study of universal properties in solids which possess phases with an incommensurately modulated structure. As a third example, I will show how NMR and EPR may contribute to elucidate the properties of solids with particle sizes in the range of nanometers.

63

AN ATTEPT TO TRACE NERVOUS FIBERS IN A RAT SPINAL CORD BY DTI

Artur Mielczarek

Institute of Nuclear Physics, PAS, Kraków, Poland Diffusion tensor imaging (DTI) is an experimental technique which enables a voxelwise recovery of the diffusion tensor field in the whole imaged volume. With it one can try to trace nerve fibers, both in central and peripheral nervous systems. Such a tracing is one of few techniques that can provide insight into nerve bundles connectivity in vivo. Attempts are made to correlate reconstructed tracts with various diseases and damages of tissue. The tracing is based on an assumption that the direction of the most rapid diffusion, indicated by the largest diffusion tensor eigenvector, is more or less colinear with fiber bundles. There are numerous algorithms available with which fiber tracing can be performed. So far, I used a simple one, namely a kind of the streamline tractography algorithm, which follows the largest diffusion tensor eigenvector until a tresholding value of fractional anisotrophy (FA) is reached. The diffusion tensor field, whose eigenvectors were sought, was smoothed with a planar Gaussian filter in order to make the result less dependent on acquisition noise during the DTI experiment. The method gives rather a poor outcome; in regions of fibers intersection or fiber branching all but none; hence has to be interchanged by some more robust one.

64

THE INFLUENCE OF DRAWING ON MOLECULAR MOBILITY IN POLYPROPYLENE FIBERS

Ľubomír Mucha, Jozef Murín, and Jana Kaššovicová

Department of Physics, Technical University of Košice, Košice, Slovakia E-mail:[email protected] The influence of drawing at a certain temperature on molecular mobility of polypropylene (PP) fibers has been studied by means of broad-line nuclear magnetic resonance (NMR). Both, drawing and temperature of drawing influence physical properties of PP fibers. NMR technique is shown to be advantageous for study of these changes on molecular level since the shape of broad-line NMR spectra and processes of the NMR relaxation depend on the spatial configuration and motion of the resonating nuclei. Our measurements were performed on the sets of polypropylene fibers made from isotactic PP marked as Tatren 430 produced in Slovakia. Fibers were drawn at the temperatures Td = 293 K and 373 K to draw ratio λ from 1 to 5.5. The NMR measurements were carried out on spectrometer RYa - 2301 in the temperature range 200 - 400 K at the resonance frequency f0 = 14.1 MHz. The samples were prepared from fibers densely wounded on a thin teflon rod in the form of small solenoid. The axis of solenoid was perpendicular to external magnetic field. NMR spectra have been analysed by means of modified Bergmann’s method [1] on assumption that each spectrum measured at a given temperature may be expressed as a sum of three elementary spectra y(x) = wn yn(x, Bm, βL) + wm ym(x, βmL, βmG) + wb yb(x, s) (1) in which x = B - B0 is a difference between the applied magnetic field induction B and the resonance magnetic field B0, Bm is the amplitude of modulating magnetic field. The narrowest spectral component yn, corresponding to the chains with highest mobility, is the Lorentzian function influenced by modulation field. The middle component ym, corresponding to the chains with hindered mobility, is the product of the Lorentzian and Gaussian functions. The broad component yb, representing rigid (immobile) chains of crystalline and highly oriented non-crystalline regions, is an experimental NMR spectrum measured at the lowest temperature - 200 K in our case. The weight factors wn, wm, wb determine the relative number of the macromolecular chains in the three above mentioned phases, differing in their structure and chain’s mobility. The weight factors fulfil the condition wn + wm + wb = 1. Parameters βL, βmL, βmG and s determine the widths of corresponding elementary spectra. The decomposition of the NMR spectrum has been realized by fitting the experimental spectra according to equation (1) by the least square method [1].

The temperature dependences of the wi (i = n, m, b) indicate that drawing of PP fibers and temperature of drawing influence molecular mobility of PP chains in the temperature region corresponding to the β-relaxation. Reference: [1] Uhrín, J., Murín, J., and Olčák, D., Acta Physica Slovaca 34 (1984) 209.

65

NMR STUDY OF LOW DENSITY POLYETHYLENE FILLED WITH HIGH SURFACE AREA SILICA

Józef Murin, Ján Uhrin, Ladislav Horváth, Ladislav Ševčovič, Ľubomír Mucha,

and Jozef Onufer

Department of Physics, Technical University of Košice, Košice, Slovakia E-mail: [email protected]

Physical modification of polyolefins (such as polyethylene and polypropylene) with

different kinds of organic as well as inorganic fillers is one of the most economic ways to improve their deformation and strength parameters, impact resistance, processing characteristics, thermal stability, etc. Properties of the filled material depend on the amont and on surface activity of the filler used, and on conditions of preparation [1, 2]. A small particles of a filler introduced into a polymer matrix may cause the local changes in mobility and special organization of the macromolecular chains. The greater the filler content, the greater changes would be expected. NMR method is very suitable for characterization these local changes introduced by filler, when compared with neat polymer.

In this presentation we investigate the phase structure of low density polyethylene (LDPE, Bralen RA2-63, Slovnaft, Slovak Republic) modified by particulate silica fillers with the three different specific surface arrears SA: (SiO2-SG97 with SA=138 m2/g, SiO2-Ultrasil VN-3 with SA~150 m2/g and SiO2-SG220z with SA=185 m2/g). These fillers are H1-NMR inactive in LDPE. The blends were mixed in the chamber of a Brabender PLE 331 plastograph at 130 °C for 16 min. at 35 rpm. Small plagues were prepared in a laboratory press at 155 °C. The silica concentration in LPDE was 40 wt%.

WL-NMR spectra were recorded in differential form by means of NMR spectrometer operated at the fixed external magnetic field B0=0,247 T for H1-nuclei with the frequency sweep [3], at the three stabilized temperatures: 143 K, 203 K and 253 K, respectively. The spectra recorded at the broadest spectral have been used for modeling of the lowest temperature have been used for modeling of the broadest spectral component, representing regions with “immobile” PE chains.

The phase structure of the materials has been derived from spectra measured at the temperature of 253 K, where three spectral components may be unambiguously resolved: narrow – yn(x) corresponding to amorphous regions with the intense motion, medium – ym(x) corresponding to regions with restricted motion and broad – yb(x) corresponding to crystalline regions and interfacial regions with “immobile“ chains firmly bound to the filler surface. NMR spectra were analysed according to the modified Bergman`s method [4]. According to this method the NMR spectrum (at temperatures T>Tg ) may be represented as the summ:

)()()()( xywxywxywxy bbmmnn ++++++++====

where wn, wm and wb are weight factors representing relative number of H1-nuclei corresponding to regions classified above and x = B – B0. The spectral functions yi(x) are characterised by their width`s δi listed in Table 1., together with the weight factors wi, characterising the phase structure of the materials at temperature T = 253 K. Conclusions

As we can see from Table 1., the influence of silica fillers on phase structure of LDPE may be summarized in following way:

66

Table 1. Parameters characterizing the phase structure of LDPE filled with silica with different specific surface area SA.

1. The amount of amorphous regions in filled LDPE is a little diminished (from wn = 0,04 up to 0,03 or 0,02).

2. The weight factor wm decreases with the SA of the filler particles: wm varies from 0,55 to 0,42.

3. The weight factor wb shows the opposite coarse: it increases from 0,55 to 0,42 with increasing of specific surface area SA.

sample wn wm wb δn δm δb

LPDE 0,04 0,54 0,42 2,1 6,0 14,5

SG97 138 m2/g

0,03 0,55 0,42 1,0 4,0 13,4

Ultrasil 150 m2/g

0,02 0,49 0,49 1,0 4,4 14,0

SG 220z 185 m2/g

0,03 0,42 0,55 1,0 4,6 13,5

δi are in 10-4 T unit

Acknowledgements: Authors are indebted to I. Chodák and Z. Nógellová, Polymer Institute Slovak Academy of Sciences, Bratislava for supplying samples. References: [1] R. A. Fara (Ed.) Methods of experimental physics, Vol. 16, Polymers, part A, Molecular Structure and Dynamics, Academic Press, New York (1980); [2] I. Janigová and I. Chodák, Eur. Polym. J. 30 (1994) 1105; [3] L. Ševčovič and F. Mede, J. Electrical Eng. Vol. 42 (1991), 584; [4] J. Uhrin, J. Murin, and D. Olčák: Acta Phys. Slovaca 34 (1984), 209.

67

A CONFORMATIONAL STUDY OF SOME BENZOSUBERONE SYSTEMS BY USING GIAO/DFT NMR CALCULATIONS

Ryszard Bolesław Nazarski

Department of Organic Chemistry, Institute of Chemistry, University of Łódź, Łódź, Poland E-mail: [email protected] There is a considerable discrepancy in the literature concerning the shape of conformationally mobile seven-membered ring joined to an aromatic moiety in 1-benzosuberone (1). Indeed, recently Abraham et al. in their GIAO/DFT-supported analysis of the 700 MHz 1H NMR spectrum of 1 measured in CDCl3 proposed the value of 37 ±5o for a torsion angle θ of the carbonyl group with respect to a benzene ring in this ketonic system [1]. However, such a computational finding is in sharp contrast to an earlier LIS NMR (1H, 13C) investigation [2] suggesting the angle is 56o, in reasonable agreement with the PE spectroscopy data (θ = 60o) and results from various force-field calculations (53 ≤ θ ≤ 67o) [1,2]. In assay of finding an explanation of the aforementioned disagreement in interpretation of

experimental data, both single differently puckered conformers and some overall (time-averaged, see [3]) forms of 1 were considered in the light of GIAO/DFT 1H and 13C NMR responses found for various combination of hybrid density functional and basis set employed. The standard gas-phase approximation was used. All results were analyzed in view of pertinent ∆Go

298 data from the 0.96-scaled [4] vibrational calculations at the B3LYP/6-31G* theory level. In addition, three methyl disubstituted benzoannulated systems 2-4 [5] were investigated in the same way. Generally, statistical fitting (δXn

calcd vs. δXnobsd; where X = C and/or H, n = 1 or 2 [3]) was

regarded as the best proof of correctness of the proposed solution conformations. Interestingly, a single chair form adopted in solution by a lactonic analogue of 1 with the oxygen atom in the position 2 was reported very recently on the basis of thoroughly performed DFT NMR analysis of experimental spectra [6]. Acknowledgements

The author thanks Profs. Raymond Abraham and Miguel Garcia-Garibay for kindly supplying NMR data and spectra concerning title compounds. This work was partially supported by a grant No 505/662/2004 from the University of Łódź.

Literature: [1] Abraham RJ, Mobli M, Smith RJ, Magn. Reson. Chem. 2003, 41, 26; [2] Epsztajn J, Bieniek A, Brzeziński JZ, Kalinowski H-O, Tetrahedron, 1986, 42, 3559 and refs therein; [3] Michalik E, Nazarski RB, Tetrahedron, 2004, 60, 9213; [4] Curtiss LA, Raghavachari K, Redfern PC, Pople JA, Chem. Phys. Lett. 1997, 270, 419; [5] Johnson BA, Kleinman MH, Turro NJ, Garcia-Garibay MA, J. Org. Chem. 2002, 67, 6944; [6] Stankiewicz A, Migda W, Szneler E, Serda P, Rys B, Symposium on Nuclear Magnetic Resonance in Chemistry, Biology and Medicine; Warszawa, 8-10.09.2005, poster P-36.

O

R1

R2

R3

R4

1 R1 = R2 = R3 = R4 = H2 R1 = R4 = CH3, R2 = R3 = H3 R1 = R4 = H, R2 = R3 = CH3

4 R1 = R3 = D, R2 = R4 = CD3

68

EQUILIBRIUM CONSTANT DETERMINATION BY NMR. ADVANTAGES OF LINESHAPE ANALYSIS

Michał Nowakowski1, Andrzej Ejchart 1, Piotr Bernatowicz1, and Helena Dodziuk2

1 Laboratory of Biological NMR, Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland 2 Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland Equilibrium constant for a reaction of complex formation can be determined by analysis of NMR spectra. Chemical shifts of species engaged in the reaction are population-weighted averages of chemical shifts of individual forms i.e. free and complexed. This is the truth, however, only in the limit where the exchange is very fast compared to the chemical shift difference. If the exchange is not fast enough, then signals bear residual broadening coming from the exchange, and their apparent maxima are shifted to the direction of higher populated form. Use of averaged chemical shifts taken directly from such spectrum may lead, therefore, to substantial systematic errors in equilibrium constant estimation. In order to overcome these difficulties the full NMR lineshape analysis is required. We show advantages of the latter technique extracting both the kinetic and thermodynamic parameters from spectra of complexes formed by both camphor enantiomers with alphacyclodextrin.

69

ACTIVATION OVER A FLUCTUATING BARRIER: CALCULATION OF DIPOLAR CORRELATION FUNCTION

Marcin Olszewski and N.A.Sergeev

Institute of Physics, University of Szczecin, Szczecin, Poland

Many of NMR experimental values such as the second moment of NMR spectrum, spin-lattice relaxation rates, the time position and the amplitude of the solid echo signals, and others are governed by the dipolar correlation function [1]:

∑=ji

ijij tataWtth,

)'()"()',"( , (1)

where aij(t) are the values, which describe dipolar interactions between nuclear magnetic moments. The upper bar denotes the average on the random motions of spin pair i-j. Motions of molecules or molecular groups in solids are usually described by the potential wells model, in which minima correspond to possible positions of these groups in lattice. The assumption of static potential barrier leads to well-known Markov processes [2,3]. It is reasonable to expect that motions can not be Markovian for the sake of the barrier is able to be non-static, modulated by some internal degrees of freedom [4,5]. We have taken into account the existence of possible additional states when the transition probability matrix become random, and the master equation transforms into the stochastic equation.

We have considered two-site model with fluctuating activation energy E, which as we expect is the Ornstein-Uhlenbeck (OU) process (Markov Gaussian process). Since rate constant W and E are connected with each other by the Arhenius activation law, W is described by the Markov log-normal process with drift and diffusion coefficients (Fokker-Planck equation) [3]:

WRT

WWbW

WWWa a

aa

2

2)(,ln)(

=−= σνν , (2)

where

−=RT

EWW a

a exp0 , ν and σ2 are rate constant and dispersion of the fluctuations. In linear

approximation of the drift we can write coefficients (2) in the form: gWWbgzWWa νν 2)())1(()( =+−−= , (3)

where 2

=RT

Wg a

σ and

2

1

=+σRT

z . This is the well-known gamma Pearson process. The

stochastic master equation driven by gamma Pearson process may be solve by method described in [6]. The final solution for dipolar correlation function in Laplace representation is:

∑

∑∞

=−

−

∞

=−

−

−++

−+−+=

2121

11

2121

11

22

)2(22

)2(2121

)(

kkk

k

kkk

k

sM

sMsh

δαααδ

γαααγ∆

K

K

, (4)

where 2M is the second moment of motionally narrowed NMR line and 222 MMM −=∆ where M2 is the second moment of NMR line in “rigid” lattice, αi, γi, δi are determined by recurrent relations:

70

12

1

−α+=α

iiii al

,

1−δα=δ iiii a , (5)

)( 1 iiiii fa +γα=γ − ,

with initial conditions: 0,1,0 000 === γδα . (6)

In Eq.(5) ν+= giziai )( ,

ν+= isl i , (7)

)1(

)1(

+Γ++Γ=

z

izgf i

i .

The obtained result (Eq.(4)) has been used for the calculation of the temperature dependences of spin-lattice relaxation times in the laboratory and rotating frames. References: 1. P. Bilski, M. Olszewski, N. A. Sergeev, and J. Wąsicki, Solid St. NMR 25 (2004) 15; 2. A. Abragam, The Principles of Nuclear Magnetism, Clarendon Press, Oxford 1961; 3. N.G. van Kampen, Stochastic Processes in Physics and Chemistry, North-Holland,

Amsterdam1981; 4. H. Sillescu, J. Chem. Phys., 104 (1996) 4877; 5. P. Hänggi, P. Talkner and M. Borkovec, Rev. Mod. Phys., 62 (1990) 251; 6. V.M. Loginov, Acta Phys. Polon., B27 (1996) 693.

71

COMPARATIVE EPR EXAMINATION OF GENTAMICIN, KANAMYCI N AND NETILMICIN EFFECTS ON FREE RADICALS

IN DOPA-MELAN

Barbara Pilawa1, Ewa Buszman2, Magdalena Zdybel1, Dorota Wrześniok2, and Aneta Grzegorczyk2

1Department of Medical Physics, 2Department of Pharmaceutical Chemistry, School of Pharmacy, Medical University of Silesia, Sosnowiec, Poland Free radical properties of DOPA-melanin and its complexes with gentamicin, kanamycin and netilmicin were studied by the use of electron paramagnetic resonance spectroscopy at X-band (9.3 GHz). Melanins demonstrate stable paramagnetism [1-2] and ability to drugs binding [2]. Interactions of melanins with aminoglycoside antibiotics are not well known so far. o-Semiquinone free radicals formed in melanin biopolymers may be responsible for toxic effects appearing during antibioticotherapy. In this work we compare changes in paramagnetic centers systems of DOPA-melanin - model eumelanin caused by binding of typical aminoglycoside antibiotics. DOPA-melanin was chosen for measurements, because it mainly exists in living organism. The EPR results for the individual drugs were presented in our earlier works [3-5]. EPR measurements were performed by the use of EPR spectrometer with modulation of magnetic field 100 kHz produced by RADIOPA-Poznań. Microwave frequency was recorded. The first derivative EPR spectra were recorded with low microwave power 0.7 mW at room temperature. Free radical concentration, g-factor, and linewidths were determined. Ultramarine was used as a reference of concentration of paramagnetic centers. A ruby crystal permanently placed in the spectrometer cavity was the secondary reference. Area under the absorption curve was obtained by double integration of its first derivative. g-Factor was calculated from the resonance condition.

The influence of microwave power in the range of 0.7-70 mW on EPR lines of DOPA-melanin and its complexes with the analysed antibiotics was tested. Changes of amplitudes and linewidths with increasing of microwave power were obtained.

o-Semiquinone free radicals exist in all the studied melanin complexes. It was confirmed that aminoglycoside antibiotics generate additional o-semiquinone free radicals in melanin polymer. The relatively low amount of free radicals appears in melanin after complexing with netilmicin – an antibiotic which demonstrates relatively low ototoxicity as compared with gentamicin and kanamycin.

Continuous microwave saturation of EPR spectra indicates that o-semiquinone free radicals are homogeneously distributed in DOPA-melanin and its complexes with the studied drugs. Slow spin-lattice relaxation processes and strong dipolar interactions exist in these complexes. It was shown that metal ions strongly effect properties and free radical concentration in melanin complexes with drugs. Paramagnetic molecular oxygen O2 also influences paramagnetic properties of melanin and the studied complexes. References: [1] T. Sarna, J.S. Hyde, and H.M. Swartz, Science 1976, 192, 1132-2234; [2] E. Buszman, Habilitation thesis, Medical University of Silesia, Katowice 1994;

72

[3] B. Pilawa, M. Latocha, R. Krzyminiewski, Z. Kruczyński, E. Buszman, and T. Wilczok, Physica Medica 2004, XX , suppl. 1, 111-113; [4] B. Pilawa, E. Buszman, D. Wrześniok, M. Latocha, and T. Wilczok, Applied Magnetic Resonance 2002, 23, 181-192; [5] E. Buszman, B. Pilawa, M. Zdybel, D. Wrześniok, A. Grzegorczyk, and T. Wilczok, Chemical Physics Letters 2005, 403, 22-28.

73

STRUCTURE OF SELECTED DERIVATES OF p-HYDROKSY CYNAMONIC ACID ACCORDING TO 13C CP MAS NMR

AND DFT CALCULATION

Dariusz Maciej Pisklak, Iwona Wawer, and Michał Tkaczyk Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Warsaw, Poland

Derivatives of p-hydroksy cynamonic acid are widely occuring in fruits, vegetables, tea and coffee. They exhibit strong antioxidant activity due to the presence of phenolic group. Epidemiological, biological and biochemical data support health beneficial role of this group of compounds and anticarcinogenic, antimutagenic and antiinflamatory effects have been reported. The most common caffeic acid contributes significantly to the total polyphenol intake and has been suggested to play a role in the apparent association between the regular consumption of polyphenol-rich food and beverages, and the prevetion of inflammatory and proliferative diseases.

OOH

OR

ORR

13C MAS NMR spectra were recorded on a BRUKER DSX 400 spectrometer at 400,13. Powder samples were spun in a 4mm rotor at 10kHz (13C). Signals were assigned:

• By comparison with solution spectra • Using dipolar dephasing and variable contact time experiments • Confirmed by DFT calculations of shielding constants.

The differences in chemical shifts between solution and solid state spectra are due to the formation of intramolecular and intermolecular hydrogen bonds, including C-OH…OC within cyclic dimers.

74

STRUCTURE OF G-QUADRUPLEXES AND THEIR INTERACTIONS WITH CATIONS

Janez Plavec

NMR Centre, National Institute of Chemistry, Ljubljana, Slovenia Quadruplexes are stable structures adopted by both DNA and RNA guanine-rich sequences that can be found in telomeres, immunoglobulin switch regions, gene promoter regions and have also been implicated in association with human diseases, therapeutic targets in drug design, as well as in technical applications as nanomolecular devices. Involvement of telomeres in fundamental health problems such as cancer, premature aging and early death has made G-quadruplexes a molecular target for new approaches to cancer chemotherapy. Oligonucleotides containing two G-tracts separated by several thymine residues form dimeric G-quadruplexes in which two molecules fold-back and associate to form tandem G-quartets with anti-parallel strands. We have recently determined 3D structures of dimeric quadruplexes adopted by d[G4T4G3] and d[G3T4G4] sequences. (1,2) d(G3T4G4) forms a dimeric G-quadruplex with only minor differences in key intra- and interquartet NOE intensities in the presence of K+, Na+ and NH4

+ ions which are consistent with subtle structural differences while retaining the same folding topology of the G-quadruplex. (3) The critical role that monovalent cations play in G-quadruplex formation initiated considerable efforts for identifying cation localization. G-quadruplexes exhibit cation binding sites between G-quartets. The use of 2D 1H-15N NMR experiments enabled analyses of 15NH4

+ ion movement between the binding sites within the d(G4T4G4)2 G-quadruplex. Na+ ions exhibit a smaller ionic radius that allows them to be coordinated in the plane of G-quartets. We studied movement of 15NH4

+ ion as a function of increased ionic strength, and in the presence of smaller Na+ ions which partially occupy binding sites inside d(G4T4G4)2. The lifetime of the inner ammonium ion within the d(G4T4G4)2 is reduced in the presence of Na+ ions.(4) d(G3T4G4) exhibits two cation binding sites between three of its G-quartets. Titration of tighter binding K+ ions into the solution of d(G3T4G4)2 folded in the presence of 15NH4

+ ions uncovered a mixed mono-K+-mono-15NH4

+ form that represents intermediate in the conversion of di-15NH4

+ into di-K+ form. (5) References: 1. M. Črnugelj, N.V. Hud, and J. Plavec, J. Mol. Biol. 2002, 320, 911; 2. M. Črnugelj, P. Šket, and J. Plavec, J. Am. Chem. Soc. 2003, 125, 7866; 3. P. Sket, M. Cmugelj, and J. Plavec, Bioorg. Med. Chem. 2004, 12, 5735; 4. Sket, P., Crnugelj, M.; Kozminski, and W. Plavec, J. Org. Biomol. Chem. 2004, 2, 1970; 5. P. Sket, M. Crnugelj, and J. Plavec, Nucleic Acids Res. 2005, 33, 3691.

75

CONFORMATIONAL CHANGES OF RNA DUPLEX INDUCED BY THE PRESENCE OF UNPAIRED ADENOSINE RESIDUE.

NMR STUDY

Łukasz Popenda and Zofia Gdaniec Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland

Bulges are the most frequently occurring and the simplest structural motifs found in many functionally important RNAs [1]. In our study we have determined the structural disturbances of RNA duplex induced by the presence of unpaired adenine residue. Our previous NMR studies have shown that in the duplex of the sequence I :

I II the bugled adenine residue intercalates between adjacent base pairs. In order to determine the structural changes caused by the accommodation of additional residue within the helix it is necessary, however, to establish the structure of duplex I with atomic resolution. Additionally, the structure of the reference duplex with all Watson-Crick base-pairs was obtained. It is important to notice, that in the studies of bulged RNA fragments structures obtained by the X-ray analysis differ very often from these in solution, probably due to packing forces in the crystal. High resolution NMR spectroscopy and restricted molecular dynamics were used to determine the structure of the duplexes. The calculations were performed using Xplor NIH software [2] with TAMD protocol (Torsion Angle Molecular Dynamics) [3]. Comparative and quantitative analysis of local as well as global helical parameters of both, bulged and reference duplexes, permit to draw conclusions on the effect which bulged residue induces into the regular A-RNA structure. References: 1. M. E. Burkard, D. H.Turner, and I. Tinoco Jr. in: RNA World II, R. Gesteland, T. Cech,

J. Atkins (ed), Cold Spring Harbor Press, (1999) p. 233; 2. C.D. Schwieters, J.J. Kuszewski, N. Tjandra, and G.M. Clore, J. Magn. Res., 160 (2003) 66; 3. E.G. Stein, L.M. Rice, A.T.Brunger, J.Magn Res. B, 127 (1997) 154.

76

NMR AND MOLECULAR DYNAMICS SIMULATIONS STUDY OF RNA BULGED DUPLEX

Łukasz Popenda, Łukasz Bielecki, Zofia Gdaniec, and Ryszard W. Adamiak

Institute of Bioorganic Chemistry, Polish Academy of Science, Poznań, Poland

RNA molecules can form complex secondary and tertiary structures that are intimately linked with their functions in vivo. Double stranded regions with Watson-Crick base-pairs account only for about 50% of all the residues in non-messenger RNAs. Single and multiple bulges are the simplest as well as the most abundant structural motifs that play a structural and functional role in many RNAs [1]. The aim of our study was to determine the structure of RNA duplex of the following sequence:

by high-resolution NMR spectroscopy and to compare of the results with theoretical structures extracted from computer simulation method.

The NMR structure of RNA duplex has been determined by the restricted molecular dynamics, using the structural constraints derived from NMR data. Xplor NIH [2] software was used in calculations applying molecular dynamic simulation in torsion angle space [3]. Based on the analysis of high-resolution NMR spectra, there has been 303 NOE and 173 torsion angles constraints obtained, respectively. They were taken into account in the calculations. Computer simulated structures have been obtained using AMBER 8 software [4]. Molecular dynamics simulations were performed with Amber force field without introducing any experimental data. For parallel simulations the NMR representative structure and canonical A-RNA structure were used. References: 1. M. E. Burkard, D. H.Turner, and I. Tinoco Jr. in: RNA World II, R. Gesteland, T. Cech,

J. Atkins (ed), Cold Spring Harbor Press, (1999) p. 233; 2. C.D. Schwieters, J.J. Kuszewski, N. Tjandra, and G.M. Clore, J. Magn. Res., 160 (2003) 66; 3. E.G. Stein, L.M. Rice, and A.T.Brunger, J.Magn Res. B, 127 (1997) 154; 4. D.A. Case, T.A. Darden, and T.E. Cheatham, III, C.L. Simmerling, J. Wang, R.E. Duke,

R. Luo, K.M. Merz, B. Wang, D.A. Pearlman, M. Crowley, S. Brozell, V. Tsui, H. Gohlke, J. Mongan, V. Hornak, G. Cui, P. Beroza, C. Schafmeister, J.W. Caldwell, W.S. Ross, and P.A. Kollman, AMBER 8, San Francisco: University of California, (2004).

77

SHAPE-SELECTIVE ISOMERIZATION OF 1,2,4-TRIMETHYL-BENZENE ON FERRIERITE-BASED CATALYSTS

Rafał Rachwalik,a Zbigniew Olejniczak,b Jian Jiao,c Michael Hungerc,

and Bogdan Sulikowskia

a Institute of Catalysis and Surface Chemistry, Polish Academy of Sciences, Kraków, Poland b Institute of Nuclear Physics, Polish Academy of Sciences, Kraków, Poland c Institute of Chemical Technology I, University of Stuttgart, Stuttgart, Germany

The framework Si/Al molar ratio of zeolites is an important parameter that exerts a strong influence on their properties, such as thermal and hydrotermal stability, hydrophobicity, concentration and strength of acid sites of Brønsted type. The latter affect inadvertently the course of catalytic processes (activity and selectivity). The Si/Al (framework) ratio of zeolites may be controlled by dealumination. Partial or total removal of tetrahedral aluminium from zeolites can be accomplished by: (i) dealumination performed without the addition of external source of silicon and realised either by (hydro)thermal treatments or by chemical reactions with mineral acids, chelating agents etc., and (ii) dealumination carried out with the external source of silicon added to the system (e.g., SiCl4, (NH4)2SiF6).

In this work the ammonium form of ferrierite was modified with aqueous solutions of hydrochloric acid, by applying a multistep dealumination procedure.

The ammonium form of ferrierite, purchased from Zeolyst (Si/Al=10), was calcined at 773 K for 5 h to yield the hydrogen form H-ferrierite as a reference catalyst (SSA=287 m2/g). The NH4-FER sample was dealuminated by the multi-step procedure. First, the parent sample was treated with 0.25 M HCl solution for 4 h at ambient temperature, washed until free of Cl- ions and dried. The resultant sample F1 was dealuminated further applying a similar procedure; however, the concentration of HCl was progressively increased from 0.25 to 6.0 M HCl in the consecutive steps. All the samples were then submitted to several characterization procedures i.e., X-ray diffraction (XRD) for assessment of zeolite crystallinity, specific surface area and pore-volume measurements, XPS technique for estimation of the surface Si/Al ratio, 1H MAS NMR for quantifying Brønsted acid sites, 29Si and 27Al MAS NMR for quantitative measurements of the Si/Al ratio in the framework and loss of the framework aluminium from zeolite, respectively.

The diffraction patterns show that treating the parent ferrierite with aqueous solution of hydrochloric acid did not result in any significant changes.

The surface area characteristic of parent and modified zeolite FER, as determined with nitrogen adsorption, gives a surface area in the range of 275-312 m2/g. Moreover, during the modification step some mesoporosity was developed in the samples.

The dealumination level of ferrierite was monitored quantitatively using both chemical wet analysis and 27Al MAS NMR (not shown). Continuous smooth non-linear dealumination of ferrierite was observed for the F1 to F5 samples.

The 29Si MAS NMR spectrum of NH4-ferrierite is a superposition of many signals. After deconvolution we receive five signals at −105, −115. 5, −109 and -112 ppm, which we assigned to the Si(1Al) TA, Si(0Al) TB, Si(1Al) TB and Si(0Al) TA groupings, respectively. A signal at –99 ppm can be attributed to either Si(2Al) or Si(OH) positions. We have observed preferential

78

removal of the aluminium atoms from Si(1Al) TB position. Consider the 1H MAS NMR spectrum of sample F5 measured after five dealumination

steps. It consists of three distinct lines, with the chemical shift at 4.2, 2.7 and 1.8 ppm, respectively. However, taking into account information from other systems, the experimental spectrum was simulated using four signals. Two signals at 4.2-4.6 ppm are due to the bridging OH groups corresponding to the Brønsted acid sites. The signal at 1.8 ppm is due to the silanol groups located at the external surface of the zeolite particles and defected framework sites, while the medium one at 2.7 ppm is assigned to the non-acidic OH groups bounded at extra-framework Al species. The spectrum, when compared to the parent material, shows therefore that some of Al atoms depleted from the zeolite framework sites are not extracted from zeolite crystals, but remain in the channels and at the surface. Second, the number of silanol/framework defect OH groups at 1.8 ppm is increased after dealumination. Moreover, XPS data (not shown) confirm further that the zeolite surface is indeed enriched in aluminium.

The isomerisation of 1,2,4-trimethylbenzene was chosen as a model reaction for testing the properties of parent and dealuminated ferrierite samples. This hydrocarbon is transformed on the acid centres giving a mixture of 1,3,5- and 1,2,3-trimethylbenzenes with the unreacted substrate. The isomerisation of trialkylbenzenes is, similarly to dialkylbenzenes, a typical reversible process, so that starting from any isomer and using a non shape-selective catalyst a product is expected, in which concentrations of the individual isomers would be close to the thermodynamic equilibrium. In particular, the ratio of the 1,3,5 to the 1,2,3 isomer in such the product would be ≥ 2, depending on temperature (Table).

As seen from Table, at thermodynamic equilibrium in the temperature range of 600-800 K the characteristic distribution of isomers is expected, rich in 1,2,4-TMB. The ratio between the two isomers, the products of the 1,2,4-TMB transformation, shows a strong preponderance of the most symmetric 1,3,5-isomer in the C9 fraction at equilibrium. Thus the ratio between the two reaction products, 1,3,5 to 1,2,3 isomers, is over 3 at 600 K and decreases with the temperature to about 2 at 800 K (Table).

It is clear that the shape-selectivity index as defined above is low, around one, for the parent H-ferrierite and the F1 sample. In other words, preponderance of the 1,2,3 isomer is observed for these samples, far from the composition required by thermodynamic equilibrium. We have demonstrated therefore a shape-selective isomerisation of 1,2,4-trimethylbenzene both on the parent H-ferrierite and the slightly dealuminated material.

However, if the treatment of zeolite is more severe (note that the concentration of HCl is increased in each step) and secondary mesoporous system is formed, more and more acid sites become available for the substrate. As these sites are now less confined geometrically due to the presence of mesopores, the ratio between the 1,2,3- and 1,3,5-TMB in the products is approaching values typical for equilibrium (Table). The shape-selectivity index as defined above increases with the dealumination level to a value around two, which is characteristic for the isomers distribution in products close to the thermodynamic equilibrium.

79

Table Distribution of trimethylbenzenes (mol%) at the thermodynamic equilibriuma at 600-800 K and at the reaction temperatureb 773 K for F1 catalyst.

Concentration of trimethylbenzenes (mol%)

Isomer 600 Ka 700 Ka 800 Ka 773 Kb

1,2,3-trimethylbenzene 7.59 9.68 10.48 6.10 1,2,4-trimethylbenzene 67.86 67.74 68.09 87.28 1,3,5-trimethylbenzene 24.55 22.58 21.43 6.62 1,3,5-TMB to 1,2,3-TMB ratio 3.23 2.33 2.04 1.08

In conclusion, we have demonstrated that isomerisation of 1,2,4-trimethylbenzene on H-form of parent and slightly dealuminated ferrierite proceeds in an unexpected fashion, yielding the product enriched in the asymmetric 1,2,3-trimethylbenzene. This shape-selective behaviour is due to the peculiar channel system of ferrierite and is gradually lost with the zeolite dealumination level. We are grateful to the EU for the Marie Curie Action grant TOK-CATA (no. MTKD-CT-2004-509832).

80

AN NMR STUDY OF LA 2-2XSR1+2XMN 2O7 BILAYERED

Damian Rybickia*, Devashibhai T. Adrojab, Colin J. Oatesa, Czesław Kapustaa, Peter C.

Riedic, Toby G. Perringb, G. Balakrishnand, and Don McK. Pauld aDepartment of Solid State Physics, Faculty of Physics & Applied Computer Science, AGH University of Science and Technology, Kraków, Poland

bISIS Facility, CLRC Rutherford Appleton Laboratory, Didcot, UK cSchool of Physics and Astronomy, University of St. Andrews, UK dDepartment of Physics, University of Warwick, Coventry, UK

*Email: [email protected]

We report on 55Mn and 139La zero field NMR study of the bilayered manganites,

La2-2xSr1+2xMn2O7 with x=0.3, 0.35, 0.4 and 0.5. At 4.2K, all the compounds studied exhibit signals from ferromagnetic insulating (FMI) regions (Mn4+ and Mn3+ lines) and from ferromagnetic metallic (FMM) regions (double-exchange (DE) line), which indicates a phase separation. Measurements of the spectra for different pulse spacing show a minimum of the spin-spin relaxation time T2 at the centre of the DE line for x=0.3, 0.35 and 0.4, which is a result of the Suhl-Nakamura interaction. This is in contrast with the x=0.5 doped sample, where such a behaviour is not observed, which indicates that the FMM regions are of nanometric size and shows that the size of the FMM regions in the x=0.3 and 0.35 compounds is much larger, i.e. of micrometer size. The spectra for x=0.4 and x=0.5 doped samples exhibit an additional line at 350 MHz suggesting that there are two different DE regions. 139La spectrum of all four samples shows a single resonant line. The effective magnetic field at nucleus, which is mainly of the hyperfine origin, shows a different value for the compound with the easy c-axis, x=0.3 from that for the easy c-plane, x=0.35, 0.4 and 0.5, which is attributed to the anisotropy of the local field of dipolar origin. Two Mn3+ lines are observed due to the anisotropy of the hyperfine field of spin-dipole origin. From the value of this anisotropy a difference in occupancy of the 3d 3z2-r2 and x2-y2 orbitals is derived.

81

DECAYS OF CARR-PURCELL ECHOES

N.A.Sergeeva, A.M.Panichb, and M.Olszewskia

aInstitute of Physics, University of Szczecin, Szczecin, Poland bDepartment of Physics, Ben-Gurion University of the Negev, Beer Sheva , Israel

In this report, we consider the decays of spin echoes after the n

0X

0Y ]echo180[90 −τ−−τ−

pulse sequence applied to spin systems with strong inhomogeneous broadening of the resonance lines. The case of 1n = corresponds to the well-known classical Hahn echo [1]. For 1n > this pulse sequence produces the echo signals at n2,,4,2t Kττ= as it was shown by Carr and Purcell [2, 3]. In our consideration, it has been assumed that the resonance (NMR or EPR) frequency ω is a stochastic function of time. The calculation of the echo decay was reduced to the calculation of the average value [4]

ω=υ ∫

t

0

/// dt)t()t(siexp)t( , (1)

where angular brackets L denote the average over stochastic process and “echo function”

)t(s / depends on the n and has the values 1± [4]. Using the method of calculation described in [4] and assuming that the stochastic process

may be considered as Gauss-Markovian process [4], we obtained the following results:

)2t( τ=υ )]t

exp2

texp4

t3(exp[

CCC

2C

2

τ−−

τ−+

τ+−τσ−= , (2)

)]t

exp4

t3exp4

2

texp4

4

texp4

t5(exp[)4t(

CCC

CC

2C

2

τ−+

τ−−

τ−+

τ−+

τ+−τσ−=τ=υ

, (3)

)]t

exp6

t5exp4

3

t2exp4

2

texp4

3

texp8

5

texp4

t7(exp[)6t(

CCCC

CCC

2C

2

τ−−

τ−+

τ−−

τ−−

τ−+

τ−+

τ+−τσ−=τ=υ

, (4)

)]t

exp8

t7exp4

4

t3exp4

8

t5exp4

2

texp8

8

t3exp4

4

texp12

8

texp4

t9(exp[)8t(

CCCCC

CCCC

2C

2

τ−+

τ−−

τ−+

τ−+

τ−−

τ−−

τ−+

τ−+

τ+−τσ−=τ=υ

. (5)

82

Here cτ is the correlation time, which describes the stochastic process, and σ determines the

inhomogeneous broadening of the resonance line. Eq. (2) represents the well known result [4], while Eqs. (3) – (5) represent new results. The dependences of echo signals ( )2t()(2v τ=υ≡β , K),4t()(4v τ=υ≡β ) on C/t τ=β are plotted in figures.

v2 β( )

v4 β( )

v6 β( )

v8 β( )

β0 5 10 15

0

0.5

1

2.022 =τσ C

v2 β( )

v4 β( )

v6 β( )

v8 β( )

β0 5 10 15

0

0.5

1

5.022 =τσ C

v2 β( )

v4 β( )

v6 β( )

v8 β( )

β0 5 10 15

0

0.5

1

122 =τσ C

v2 β( )

v4 β( )

v6 β( )

v8 β( )

β0 5 10 15

0

0.5

1

522 =τσ C

From Eqs. (2) – (5) we obtain that in the case cτ>τ

{ } )T/texp(t)(exp)n2t( 2c2 −≡⋅τσ−=τ=υ , (6)

so in this case the decays of all Carr-Purcell echoes are described by the same spin-spin relaxation time c

212T τσ=− . This result was not noted in [1-4].

In the case cτ<τ from Eqs.(2) – (5) we have

⋅τ

σ−=τ=υ 3

c

2

2t

3)n2(

1exp)n2t( . (7)

At the certain definite value of time ( constt = ) from Eq.(7) it follows that )])1n2(t[)n2t( τ−=υ>τ=υ , and so the echo signal at τ= n2t damps slowly than the echo

83

signal observed at τ−= )1n2(t . This is also the well known result obtained for the case of diffusion in inhomogeneous magnetic field [1-3]. References: [1] E.L. Hahn, Phys. Rev., 80, 580 (1950); [2] H.Y. Carr and E.M.Purcell, Phys. Rev., 94, 630 (1954); [3] B. Herzog and E.L. Hahn, Phys. Rev., 103, 148 (1956); [4] J.R. Klauder and P.W. Anderson, Phys. Rev., 125, 912 (1962).

84

THE USE OF 1H-NMR SPECTROSCOPY IN CONTROLLING THE SYNTHESIS OF CLOPIDOGREL

Maciej SkarŜyński, Bogdan Zagrodzki, Anna Bielejewska,

Magdalena Glice, and Wioleta Maruszak

Pharmaceutical Research Institute, Warsaw, Poland

Clopidogrel is an antithrombonic agent; it is used to prevent strokes and heart attacks in patients at risk for these problems.

S

N

Cl

O O

H2SO4*

The purity of the final product of its synthesis strongly depends on the amount of a methyl derivative (the formula below) formed as a by-product at a previous stage of the process.

S

N

Cl

O O

A proton-NMR method for simple, rapid and exact determination of the methyl derivative at the level of 1% (process analysis) is described. It also enables at the same time to identify (and to determine) residual amounts of solvents used in the process (e.g. methylene chloride).

85

THEORETICAL AND EXPERIMENTAL NMR PARAMETERS OF SUBSTITUTED PURINES

Stanislav Standaraa, Kateřina Maliňákováa, Zuzana Zacharováa,

Jaromír Toušekb Michal Hocekc, and Radek Mareka

a National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic b Department of Theoretical and Physical Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic c Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Prague, Czech Republic

Structural modifications of the purine bases, nucleosides, and nucleotides have resulted in the discovery of thousands of biologically active compounds, including many clinically used drugs. The proper characterization of the electron density distribution in the variously substituted purine derivatives is of great importance and significance due to the governing effect of electron distribution on the intermolecular interactions. NMR chemical shifts and indirect spin-spin coupling constants represent very sensitive probes for studying the electron distribution in these heterocycles [1].

The variously substituted purine derivatives were investigated theoretically by DFT (B3LYP/6-311+G**) and experimentally using 1H-, 13C-, and 15N-NMR spectroscopy in the solution. DFT calculations of chemical shifts and scalar coupling constants were used for supporting and explaining the experimental data.

THIS WORK WAS SUPPORTED BY THE MINISTRY OF EDUCATION OF THE CZECH REPUBLIC (MSM0021622413). Reference: 1. R. Marek, V. Sklenář, Annu. Rep. NMR Spectrosc., 2005, 54, 201-242.

86

CONFORMATIONAL ANALYSIS OF BENZANNELATED NINE-MEMBERED RING LACTONES

Anna Stankiewicz and Barbara Rys

Department of Organic Chemistry, Jagellonian University, Kraków, Poland

Conformational analysis of medium sized ring lactones was extensively studied by Pawar and co-workers [1]. Benzoannelation of a lactone, introduce an additional strong constraint to the ring which may change the conformational properties of such system. Compounds 1, 3 were obtained via Bayer Villiger oxidation of the respective 8-membered ketones. Methyl derivative 2 was prepared from 1 using standard procedure (LDA/MeI). The structure of synthesized compounds was established by 1H, 13C NMR spectra analysis, while the signal assignment was done with the assist of COSY, HETCOR and NOE difference spectra.

O

O

R

OO

1 R = H; 3 2 R = CH3

In order to determine conformational characteristics of investigated compounds,

molecular mechanics calculations were performed to localize the energy minima on the potential energy surface, which were further optimized using DFT methods (B3LYP/6-31G**). Chemical shifts (δ) (GIAO-DFT – MPW1PW91/6-311G**) and homonuclear coupling constants (JH-H) (B3LYP/CC-PVTZ) were calculated and compared with experimental ones obtained from

1H and

13C NMR spectra [2].

Additional conformational analysis was carried out using 1H and 13C DNMR methods. Conformational preferences of the molecules 1-3 in solution and for isolated molecules

will be discussed in terms of conformational equilibrium and the ground state conformation. [1] (a) Pawar, D.M.; Moody, E.M.; Noe, E.A. J. Org. Chem. 1999, 64, 4586-4589, (b) Pawar, D.M.; Smith, S.V.; Noe, E.A. J. Mol. Struc. 1999, 255-259, (c) Pawar, D.M.; Smith, S.V.; Moody, E.M.; Noe, E.A. J. Am. Chem. Soc. 1998, 120, 8241-8244. [2] (a) Helgaker T., Jaszunski M., Ruud K. Chem. Rev. 1999, 99, 293, (b) Fukui H., Baba T. Nucl. Magn. Reson. 2002, 31, 122.

87

NMR ANALYSIS OF RNA BULGED STRUCTURES: TABU SEARCH APPLICATION IN NOE SIGNAL ASSIGNMENT

Marta Szachniuk1,2, Łukasz Popenda1, Zofia Gdaniec1,

Ryszard W. Adamiak1, and Jacek BłaŜewicz1,2 1Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland 2Institute of Computing Science, Poznan University of Technology, Poznań, Poland

Bulges (Fig. 1) are the most frequently occurring RNA secondary structural elements of high functional importance [1]. At present, they are known to participate in the process of RNA folding, RNA-RNA and RNA-protein interactions [2]. It has been shown that bulges can induce destabilization in RNA duplexes and the extent of the destabilization depends on many factors such as the size of the bulge, the nature of the bulge bases, and the flanking residues. However, relatively very little is known about these structural elements. Only several studies have been

performed to address the preferred conformations of bulged residues in DNA and RNA duplexes.

The knowledge of spatial structure of RNA bulges in solution requires application of NMR spectroscopy. A considerable part of NMR analytical process of RNA fragment is based on automatic methods. However, manual assistance is still essential in resonance assignment. Thus,

there has been a great need to introduce automatic procedures also at this level. We propose a tabu search algorithm being a tool for an automatic resonance assignment.

The assignment is determined by NOE pathways, which can be constructed in aromatic/anomeric region of 2D NOESY spectrum generated during NMR experiment. Computational tests demonstrate performance of the tabu search applied to the experimental spectra of RNA bulged duplexes. References: [1] M.E. Burkland, D.H. Turner, and I. Tinoco Jr, “Schematic Diagrams of Secondary and Tertiary Structure

Elements” in RNA World II, R. Gesteland, T. Cech and J. Atkins, Eds. Cold Spring Harbor Press, 1999, pp. 681-685;

[2] T. Herman and D.J. Patel, “RNA bulges as architectural and recognition motifs”, Structure Fold. Design, vol. 8, 2000, pp. 47-54.

Fig. 1. Exemplary schemes of bulge motives.

88

1H NMR, 13C NMR AND COMPUTATIONAL DFT STUDY OF THE SOLUTION STRUCTURE OF 2-FORMYLCYCLOHEXANE-1,3-DION E

AND ITS ALKALI METAL SALTS

Przemysław Szczeciński, Adam Gryff-Keller , and Sergey Molchanov Faculty of Chemistry, Warsaw University of Technology, Warsaw, Poland

O H

O

H

O

O

H

O

O H

Triketones have been known for many years to be efficient inhibitors of (4-hydroxyphenyl)pyruvate dioxygenase (HPPD), an enzyme very important for plants and animals, which catalyzes the tyrosine catabolism. Inhibition of this process has been used for both herbicidal and medical purposes. The mechanism of inhibition of HPPD by triketones is still under investigation. Recently, an almost complete mechanistic model of interaction between the mentioned enzyme and its inhibitor has been proposed. However, some arguments used by the authors to rationalize the proposed mechanism cannot be accepted. Therefore further developing of the investigation in this field is justified. In the present work the solution structure of 2-formylcyclohexane-1,3-dione, a simple molecular model of HPPD inhibitors, has been investigated using 1H and 13C NMR spectroscopic methods and theoretical DFT-based calculations.

89

THE STRUCTURE OF THE OXIDATION PRODUCTS OF IMATINIB STUDIED WITH 1H- AND 13C-NMR SPECTROSCOPY

Wojciech Szczepek 1, Maciej SkarŜyński 1, Piotr Cmoch 1,2,

Wojciech Łuniewski 1, and BoŜena Kosmacińska 1

1 Pharmaceutical Research Institute, Warsaw, Poland 2 Institute of Organic Chemistry, Polish Academy of Science, Warsaw, Poland

Imatinib mesylate (known as gleevec) is used to treat certain types of cancer including Chronic Myeloid Leukemia (CML) and Gastrointestinal Stromal Tumors (GIST). The following substances were isolated and identified as the products of oxidation of imatinib with hydrogen peroxide during stress testing.

NH NH N

NO

N

N

NO

NH NH N

NO

N

N

N

O

NH NH N

NO

N

N

N

O

O

A set of 1H- and 13C-NMR data is presented, which allows to identify these compounds and to study their srtucture, both as pure bases and salts (mesylates).

90

MOBILITY OF D 2 AND CD4 MOLECULES IN CAGES OF ZEOLITE NaY AS STUDIED BY DEUTERON NMR RELAXATION

A.M. Szymocha, J.S. Blicharski1, Z.T. Lalowicz, and A. Gutsze2

Institute of Nuclear Physics PAS, Kraków, Poland 1Institute of Physics, Jagellonian University, Kraków, Poland 2Biophysics Department, Medical Academy, Bydgoszcz, Poland

Nuclear magnetic resonance methods are extensively used to study molecular dynamics in all three states of matter. Insertion of D2 and CD4 molecules into the zeolite supercage provides opportunities for studying its translation and rotational dynamics.

The theory of deuteron spin-lattice relaxation for free D2 quantum rotors is developed. Relaxation rates are calculated for orhto-D2 and para-D2 [1]. The spin-rotational interaction as well as quadrupole and dipole-dipole interactions under interference conditions are taken into account. Relaxation rates, to be compared with experiment, are derived as sums of contributions from separate rotational states according to their Boltzmann populations. The theory is applied to explain relaxation rates measured in wide temperature range for D2 molecules in zeolite cages. At high temperatures (above 100K), a scattering of molecules on the cage walls provides the relaxation mechanism. At low temperatures, molecules stay close to the surface and undergo reorientations in a potential introduced by the adsorption centers.

Deuteron spin-lattice relaxation was also applied to study mobility of CD4 molecules inserted in cages of zeolites NaY [2]. There are two interconnected sets of cages: α-cages and β-cages with 1.16 and 0.74 nm diameter respectively. The temperature dependence of the spin-lattice relaxation rate for CD4 molecule trapped into the cages of NaY zeolites was measured. At high temperatures exchange between cages dominants and the molecules are expected to move freely inside the cages, colliding elastically with their walls. Increasing rate of translational motion leads to a significant reduction of the ralaxation rate. When the temperature is lowered, the interaction of CD4 molecules with the adsorption centers present on the walls surface can be observed. Molecules in the α-cages exhibit reorientational freedom, while motion of these in β-cages is significantly restricted. Increasing abundance of molecules in β-cages indicates slow diffusion down to low temperatures. References: 1. Appl. Magn. Reson. 27, 183-195 (2004); 2. Chem. Phys. 311, 299-305 (2005).

91

1H NMR STUDY OF INTERNAL DYNAMICS OF 4-AMINOPYRIDIN IUM CATION UNDER HIGH HYDROSTATIC PRESSURE

1Jolanta Świergiel, 1Krystyna. Hołderna-Natkaniec,

2Wojciech Medycki, and 3Ryszard Jakubas 1Institute of Physics, Adam Mickiewicz University, Poznań, Poland 2Institute of Physics, Polish Academy of Sciences, Poznań, Poland 3Faculty of Chemistry, University of Wrocław, Wrocław, Poland

The subject of our studies are two ferroic crystals built of an almost planar cation of 4-aminopyridinium (4-apyH)+ and a tetrahedral (SbCl4)¯ or octahedral (SbCl6)¯ anion, respectively. The X-ray diffraction study indicate that the crystals structure is build of polyanionic chains of (SbCl4¯ )n and (SbCl6 ̄ )n forming a tunnel-like structure and the (4-apyH)+ cations connected via weak hydrogen bonds to the chlorine atoms. The differential scanning calorimetry study shows a complex sequence of phase transitions in (4-apyH)SbCl4 at 304 K, 270.5/271 K, 248.5/250.5 K and 240/245 K [1], and in (4-apyH)SbCl6 at 305/380 K on cooling/heating, respectively. The phase transitions of these compound may be correlated to the reorientation of 4-aminopyridinium cation. The N-H…Cl hydrogen bonds play an important role in the mechanism of these phase transitions.

T [K]

100 200 300 400

M2

[Gs2 ]

0

3

6

9

120,1 MPa230 MPa520 MPa

T [K]

100 200 300 400

M2

[Gs2 ]

0

4

8

12

16

0.1 MPa230 MPa520 MPa

Fig. 1. Temperature dependence of the second moment of 1H NMR line of (4-apyH)SbCl4

(a) and (4-apyH)SbCl6 (b) at different hydrostatic pressures.

Molecular dynamics in both polycrystalline samples was studied on the basis of temperature dependence of the second moment of 1H NMR line (M2) under different hydrostatic pressures [2]. The values of the activation parameters of internal motions, i.e. activation energy and activation volume, were estimated. At atmospheric pressure activation energy Ea was estimated as 8.8 and 7.2 kcal/mol for the (4-apyH)+ cation attached to the SbCl4¯ or SbCl6¯ anion, respectively. Under the hydrostatic pressure the height of the barrier for the cation reorientation increased to 9.5 and 7.6 kcal/mol at 230 MPa , and at 520 MPa up to 10.1 and 8.2 kcal/mol in the two samples studied, respectively. The activation volume was calculated according to the formula ( )Tc p/lnRT*V ∂∂= τ∆ as 2.3 and 1.9 cm3/mol for (4-apyH)SbCl4 and

(4-apyH)SbCl6, respectively. The ratio ∆V*/V m was close to 0.014 for both samples, which

(a) (b)

92

allows a conclusion on the in-plane reorientation of the (4-apyH)+cation. The weaker hydrogen bonds in (4-apyH)SbCl6 seem to be a reason for higher mobility of this group. References: [1] R. Jakubas, Z. Ciunik, and G. Bator , Phys. Rev. B67, 024103, 2003; [2] W. Medycki, J. Świergiel, R. Jakubas, and K. Hołderna-Natkaniec, Acta Phys. Polonica A, 108, 161, 2005.

93

QUANTUM CHEMICAL CALCULATIONS OF 15N NMR CHEMICAL SHIFTS OF Pd AND Pt COMPLEXES WITH NITROGEN CONTAIN ING

HETEROCZCLES

Jaromír Toušeka, Leszek Pazderskib, and Radek Marekc

a Department of Theoretical and Physical Chemistry, Faculty of Science, Masaryk University, Brno, Czech Republic b Faculty of Chemistry, Nicholas Copernicus University, Toruń, Poland c National Center for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czech Republic

Platinum complexes with the nitrogen containing heterocycles were recognized as an active substances in antitumor treatment. 15N NMR spectroscopy combined with the quantum chemical calculations can be used for the study of the electron density distribution in the molecule, that determine its biological activity.

The aim of this study was to find out the most appropriate method for the 15N NMR chemical shifts calculation of the Pd and Pt complexes with the nitrogen containing heterocycles. Calculations were performed with the Pd and Pt complexes with simple ligands (pyridine, 2,2'-bipyridine and 1,10-phenantroline). Geometries of these compounds were found in the Cambridge crystallographic database. These input geometries were then optimized using various methods. Calculations of chemical shielding constants were performed with the LANL2DZ, CEP-31G and SDD ECPs using Gaussian 98 software and with the ZORA Hamiltonian using ADF software1.

The best results were obtained when the geometry was optimized by the RHF/CEP-31G method and chemical shielding constants were calculated using B3LYP/CEP-31G method. Rmsd between the experimental and calculated values was 4.41 ppm and experimental trends were also reproduced in most cases.

This work was supported by the Ministry of Education of the Czech Republic (MSM0021622410) as well as the bilateral PL-CZ cooperation project (25/2004/PL/CZ – 5693/R04/R05 – CZ/PL 13/2004). Reference: 1. G. T. Velde, F. M. Bickelhaupt, E. J. Baerends, C. F. Guerra, S. J. A. Van Gisbergen, J.G. Snijders, and T. Ziegler: J. Comp. Chem. 22, 931 (2001).

94

CORRELATION OF DEUTERIUM MOBILITY WITH QUADRUPOLE COUPLING CONSTANTS FOR RUTHENIUM COMPLEXES

- AN NMR STUDY

Bernadeta Walaszek§, Anna Adamczyk

§, Tal Pery

§, Karine Philippot

†, Bruno Chaudret

†,

Hans-Heinrich Limbach§, and Gerd Buntkowsky*

§Institut für Physikalische und Theoretische Chemie, Freie Universität Berlin, Berlin, Germany *FSU Jena Institut für Physikalische Chemie, Jena, Germany †Laboratoire de Chimie de Coordination du CNRS, Toulouse Cedex 04, France

2H solid state NMR spectra and simulations of ruthenium complexes are presented in this work. The complexes are Tp*RuD(THT)2 (I ), Tp*RuD(D2)2 (II ) and (PCy3)2RuD2(D2)2 (III ). By the line shape analysis one can determine the quadrupole coupling constants, which can be used in solid state NMR as chemical shifts in liquid state NMR are used. Good understanding of deuterium mobility in those complexes is very important nowadays because they serve as models for investigations of more complicated systems as ruthenium nanoparticles. The determined values of quadrupole coupling constants are: :Ru-D (66-70 kHz), Ru-D2 (40-42 kHz), Ru-D5 (30-34 kHz), Ru-D6 (24-26 kHz), and C-D 120 kHz. Line shape analysis are made with a matlab program by superposition of four lines for four different quadrupole coupling constants. The measurements were performed in the temperature range 50 K – 300K. In complexes (II ) and (III ) the incoherent exchange has been frozen out at deeper temperatures.

95

13C CPMAS NMR STUDIES OF ANTHOCYANIDINS AND THEIR GLUCOSIDES

Michał Wolniak and Iwona Wawer

Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Warsaw, Poland

Anthocyanins are responsible for red, purple or blue colours of flower petals and can be found in red or black fruits and berries. Many foods, especially red grapes and wines, aronia or blueberries contain large amounts of anthocyanins. Their health beneficial effects are related to antioxidant and radical scavenging properties. Structural analysis of anthocyanins by NMR are few, owing to the difficulty in obtaining analysable spectra for unstable, interconverting compounds, available in small amounts. Compounds studied by us were isolated from fruits and berries.

The structure of cyanidin, the most popular anthocyanidin, is shown below:

O

OH

HO

OH

OH

OH

13C CPMAS NMR spectra were recorded on a Bruker DSX-400 spectrometer for solid chlorides of: cyanidin, cyanidin 3-O-glucoside, cyanidin 3,5-O-diglucoside, pelargonidin and pelargonidin 3-O-glucoside. Dipolar dephased and short contact pulse sequences were used as an aid in the assignment of resonances in CPMAS spectra of solids. Inspection of the spectra indicates that anthocyanidins are in the form of flavylium (cationic) and not in form of the chalcone.: the resonance of C2 appears at ca. 160 ppm and C3 at ca. 135 ppm, whereas C ring opening produces C2=O, for which chemical shift of ca. 180 ppm can be expected.

A comparison of experimental (CPMAS) and predicted (GIAO DFT) shielding constants for cyanidin provided information about the orientation of OH groups, twist angle of aromatic ring B and the localization of the chloride anion.

96

NMR AND XAS STUDY OF FE-MO DOUBLE PEROVSKITES

Dariusz A. Zając1,2,*, Czesław Kapusta1, Marta Borowiec1, Marcin Sikora1, Clara Marquina 2, Javier Blasco2, and Manuel R. Ibarra2

1 Department of Physics & Applied Computer Science, AGH University of Science and Technology, Cracow, Poland 2 Universidad de Zaragoza, Zaragoza, Spain *) e-mail: [email protected]

The results of NMR and XAS measurements of the A2FeMoO6 double perovskites (DP) (A2=Sr2, SrBa, Ba2, Ca2) at the Fe and Mo K edges are reported and the information on the individual site electronic and magnetic properties is analysed.

The compounds studied belong to the family of materials exhibiting a high field “colossal” magnetoresistance as well as a low field “giant” magnetoresistance. Magnetoresistive properties of the compounds arise from their half-metallicity, i.e. only one spin direction being populated in the conduction band, which consists of overlapping spin down 3d Fe, 2p O and 4d Mo electron bands [1]. Within the model, a spin-down electron undergoes a fast hopping through unoccupied oxygen 2p orbitals between Fe3+ (3d5 – spin up) and Mo6+ (4d0) ionic cores. This mechanism implicates an anti-parallel coupling of the Fe and Mo spins and leads to non-integer magnetic moments and a metallic character below TC. The interaction, in analogy with the “double exchange” (DE) in manganites, is called “double exchange-like” interaction. The superexchange interaction (SE) is also expected to be present, resulting also in an anti-parallel coupling of 3d Fe3+ and 4d Mo5+ spins through occupied oxygen 2p orbitals. The insulating character of SE is connected with an increase of the tilt angle of the Fe-O-Mo bond [2], which is related to a change of the structural tolerance factor f and results in structural distortions.

The molybdenum NMR measurements revealed the existence of a non-integer magnetic moment at Mo and Fe [3,4,5], which can be attributed to the DE-like interaction. However, experiments using Mössbauer spectroscopy have shown the existence of two Fe ionisation states – with integer (SE) and non integer (DE) magnetic moments [6,7].

The 95Mo & 97Mo NMR measurements on A2FeMoO6 (A2=Sr2, SrBa, Ba2, Ca2) presented in this work show different values of the Mo hyperfine field and the corresponding magnetic moment. This is attributed to a dependence of the Mo magnetic moment on the averaged ionic radius of the alkaline earth. The highest Mo moment is observed for Sr2FeMoO6 (0.60(3) µB), where the Sr ionic radius corresponds to f of 1.007. The Mo magnetic moment derived from the value of the Mo hyperfine field decreases with the tolerance factor going away from f=1 and amounts to 0.48(3) µB for SrBaFeMoO6 (f=1.039), 0.58(3) µB for Ba2FeMoO6 (f=1.07) and 0.58(3) µB for Ca2FeMoO6 (f=0.974). A similar dependence on f is also observed for TC. This indicates that the strength of magnetic interaction is related to the magnetic moment (and the corresponding 4d electron density) at the molybdenum site. A higher TC is observed for a larger value of the magnetic moment (larger electron density) at Mo. Temperature dependence of the Mo hyperfine field exhibits a predominant T5/2 character, which indicates a half metallic nature of the compounds.

X-ray absorption measurements in the XANES range have been carried out at 300K in the transmission mode at the A1 station in Hasylab/DESY Hamburg. The edge energies correspond to an intermediate valence state of Fe, between 2.5+ and 3+ for all the investigated DP

97

compounds, with a dependence on f. For the compounds Ba2FeMoO6 and SrBaFeMoO6 a two-step feature of the absorption edge is observed. The step at higher energies is attributed to the iron valence states close to Fe3+, whereas the lower energy one is attributed to an intermediate Fe valence, in analogy with the XAS spectrum of Fe3O4. XANES measurements have also been carried out at the Mo K edge and the results show an intermediate valence state of Mo, between 5+ and 6+, similarly to that reported in [8]. A change of the edge energy with f is observed, with an opposite tendency to that obtained for Fe. This indicates the ocurrence of an electron density redistribution between the Fe and Mo sites dependent on the structural factor.

The results of NMR measurements are compared to those of XANES study and a relation to bulk magnetic and electrical transport properties, including magnetoresistance, is discussed. References: [1] K.-I. Kobayashi, T. Kimura, H. Sawada, K. Terakura, and Y. Tokura, Nature (London) 395, 677 (1998); [2] P.W. Anderson, Phys. Rev. 79, 350, (1950); [3] Cz. Kapusta, P.C. Riedi, D. Zając, M. Sikora, J.M. De Teresa, L. Morellon, and M.R. Ibarra, JMMM, 242-245, 701, (2002); [4] Cz. Kapusta, D. Zając, P.C. Riedi, M. Sikora, C.J. Oates, J. Blasco, and M.R. Ibarra, JMMM, 272-276, e1619, (2004); [5] D. Zając, NMR and XAS study of magnetic and electronic properties of double perovskites, PhD thesis, Cracow-Zaragoza 2005; [6] P.A. Algarabel, L. Morellon, J.M. De Teresa, J. Blasco, J. Garcia, M.R. Ibarra, T. Hernandez, F. Plazaola and J.M. Barandiaran, JMMM, 226-230, 1089, (2001); [7] J. Linden, M. Karppinen, T. Shimada, Y. Yasukawa, and H. Yamauchi, Phys. Rev. B, 68, 174415, (2003); [8] J. Herrero-Martin, J. Garcia, G. Subias, J. Blasco, and M.C. Sanchez, J. Phys.: Condens. Matter, 16, 6877, (2004).

98

TEETH CARIES DECAY IN MR IMAGING

Marta M. Tanasiewicz*, Władysław P. Węglarz** , Tomasz W. Kupka* , and Andrzej Jasiński**

*Department of Propaedeutics in Dentistry, Medical University of Silesia, Bytom, Poland, **Department of Magnetic Resonance, H. Niewodniczański Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland

X-ray based visualization techniques were for many years the only way to asses structure and state of the human teeth. MRI has been used in the research of the healthy and decayed teeth during last decade [1-7]. Several papers were presented showing usefulness of spin echo and gradient echo imaging, Single Point Imaging, SPRITE and STRAFI techniques for visualization of the dental surface geometry as well as for distinction between soft tissue (pulp) and mineralized tissue (enamel, dentine and root cement) in the extracted teeth. Recently, MRI was used for estimation of the facial bone structure, in preparation to implantation, localization of the tumor in the facial bone tissue, and in detection of the osteoporosis.

The aim of this work was to investigate potential of MRI for detection and estimation of the caries, on the level of laboratory pre-clinical tests. This work was done within the project to develop original, MRI based diagnostic technique for dentistry needs. MRI experiments were performed on the 5 decayed extracted human teeth (impossible conservative therapy), obtained at Dept. of Dental Surgery MUS. After extraction teeth were stored in saline. MRI measurements were done in MR Tomography Lab INP. Prior to the experiment, tooth was degassed to minimize magnetic susceptibility artifacts. A 3D spin echo pulse sequence on the 4.7 T research MRI system, equipped with Maran DRX console, and dedicated home-built probehead, was used to obtain three dimensional (256x128x128) images of the teeth. Corresponding resolution was 60x120x160 µm3. High intensity signal from water penetrated into the porous decayed regions of tooth, contrasted with lack of signal from mineralized tooth tissue, allow for visualization of the presence and extent of caries. Among the 5 measured teeth, MRI allows for detection of the caries in two most decayed tooth. High intensity signal from water penetrated into the porous decayed regions of tooth, contrasted with lack of signal from mineralized tooth tissue, allow for visualization of the presence of pores extending deep inside tooth, and being path of the moisture access into internal tooth structures. The black area of the image corresponds to mineralized tissue of the tooth which is not visible while using 3D SE pulse sequence. Water surrounding the tooth is presented in blue (artificial) color for better visualization. Approximately in the centre of tooth regular shaped area of pulp is easily recognized. Irregular, blue regions between pulp and tooth surface indicates water present in pores of the decayed tooth.

Acknowledgments: Supported by Grant no. 2 P05C 054 26 from Ministry of Science and Informatisation of Poland.

References: [1] Lloyd C.H., et. al. Quintessence Int. 28, 349-355 (1997); [2] M. Tanasiewicz, W.P. Węglarz, T. Kupka, Z. Sułek, M. Gibas, and A. Jasiński, Stomatologia

Współczesna,V, 2002;

99

[3] W.P. Węglarz, T. Kupka, M. Tanasiewicz, T. Banasik, Z. Sułek, M. Gibas, and A. Jasiński, Valetudinaria, Postępy Medycyny Klinicznej i Wojskowej. IV Zjazd Polskiego Medycznego Towarzystwa Rezonansu Magnetycznego, Bydgoszcz 2002;

[4] M. Tanasiewicz, W.P. Węglarz, T. Kupka, Z. Sułek, M. Gibas, and A. Jasiński, XXXV Ogólnopolskie Seminarium na Temat Magnetycznego Rezonansu Jądrowego i Jego Zastosowań, Kraków 2002;

[5] M. Tanasiewicz, Magazyn Stomatologiczny, 2003, XIII, 3, 64-68; [6] M. Tanasiewicz, T.W. Kupka, W.P. Węglarz, A. Jasiński, and M. Gibas, Journal of Dental

Research 2003, vol. 82, special issue B, 3047; [7] W.P. Węglarz, M. Tanasiewicz, T. Kupka, T. Skórka, Z. Sułek, and A. Jasiński, Solid State

NMR, 25, 84-87 (2004).

100

1 mT

EPR STUDIES OF SPIN-LATTICE INTERACTIONS IN Cladosporium cladosporioides AND Cladosporium herbarum MELANINS

Magdalena Zdybel1, Sławomir Wilczyński1, Teresa Witoszyńska2, Beata Brotoń1, Barbara Pilawa1, and Ewa Buszman2

1Department of Medical Physics, 2Department of Pharmaceutical Chemistry, School of Pharmacy, Medical University of Silesia, Sosnowiec, Poland

Electron paramagnetic resonance spectroscopy is useful technique to determination of melanin type in natural biological samples [1-2]. EPR spectra of eu- anf pheomelanins strongly differ in shape. Eumelanins reveal single EPR lines, whereas EPR spectra of pheomelanins are complex lines with unresolved hyperfine structure. Mixture of eu- and pheomelanins often exist in living organism. In this work we present EPR characterization of melanin biopolymers in mycelium of pigmented soil fungi Cladosporium cladosporioides and Cladopsorium herbarum, which are important in environmental protection. Melanins in these pigmented soil fungi absorb metal ions from environment. We compare our earlier EPR results [3-5] for Cladosporium cladosporioides with data obtained for Cladopsorium herbarum. EPR measurements were performed on an X-band (9.3 GHz) spectrometer with magnetic modulation 100 kHz. Continuous microwave saturation of EPR spectra was done in the range of microwave power 0.7-70 mW. Changes of amplitudes and linewidths of EPR spectra with increasing of microwave power were analysed. Free radical concentrations, g-factors, and linewidths were determined. Complex EPR spectra were measured for both Cladosporium cladosporioides and Cladosporium herbarum melanins. EPR spectra of the studied melanin biopolymers are superposition of single line of eumelanin and line with unresolved hyperfine structure of pheomelanin (Fig. 1-2). Mainly eumelanin exists in Cladosporium. EPR line of pheomelanin is clearly visible in spectra recorded at higher microwave power (attenuation 5 dB). Free radical concentrations and parameters of EPR lines of Cladosporium cladosporioides and Cladosporium herbarum are compared in Table 1. o-Semiquinone free radicals with g-vales 2.0040 and 2.0037 exist in the melanin samples. Higher concentration of free radicals was obtained for Cladosporium herbarum melanin. Strong dipolar interactions are responsible for line broadening of the measured spectra. EPR lines of both the studied natural melanins saturate at low microwave powers (Fig. 3). Slow spin-lattice relaxation processes exist in these samples. It was shown that spin-lattice interactions depend on pH of culture [6] and the presence of diamagnetic and paramagnetic metal ions [3-5]. The linewidths of EPR lines of Cladosporium melanin increase with increasing of microwave power. Homogeneous broadening of EPR lines was observed.

Fig. 1. EPR spectra of Cl. cladosporioides melanin recorded with attenuation 10 and 5 dB.

10dB 5dB

101

Fig. 2. EPR spectra of Cl. herbarum melanin recorded with attenuation 10 and 5 dB. Table 1. Free radical concentrations N, g-factors, and linewidths ∆Bpp of the analysed EPR spectra. Data for measurements at 0.7 mW (20 dB).

Melanin sample N [spin/g] g [±0.0002] ∆Bpp [±0.02 mT]

Cladosporium cladosporioides 2.1x1017 2.0040 0.41

Cladosporium herbarum 4.7x1017 2.0037 0.35

0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

0,4

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1

(M/M o)1/2

Am

plitu

de

melanin Cl. cl.

melanin Cl. h.

Fig. 3. Influence of microwave power on amplitudes of EPR lines of melanin in Cladosporium cladosporioides and Cladosporium herbarum mycelium. Mo – total microwave power produced by klystron (70 mW), M – microwave power used during the measurement. References: [1] R.C. Sealy, J.S. Hyde, C.C. Felix, I.A. Menon, and G. Prota, Science 1982, 217, 545-547; [2] E. Buszman, A. Wiewióra, and B. Bilińska, Postępy Fizyki Medycznej 1991, 26, 3-4; [3] E. Buszman, B. Pilawa, T. Witoszyńska, M. Latocha, and T. Wilczok, Applied Magnetic Resonance 2003, 24, 401-407; [4] M. Matuszczyk, E. Buszman, B. Pilawa, T. Witoszyńska, and T. Wilczok, Chemical Physics Letters 2004, 394, 366-371;

10dB 5dB

102

[5] M. Matuszczyk, E. Buszman, B. Pilawa, T. Witoszyńska, and T. Wilczok, Current Topics in Biophysics 2004, 28, suppl. A, 12th Conference of Polish Biophysical Society, Wrocław 2004, abstr. p. A-38 [61]; [6] B. Pilawa, E. Buszman, A. Gondzik, S. Wilczyński, M. Zdybel, T. Witoszyńska, and T. Wilczok, Acta Physica Polonica A 2005, 108, 147-150.

103

13C CP MAS NMR AND GIAO-CHF/DFT CALCULATIONS OF FLAVONOIDS: MORIN, TRICIN, GENISTEIN, FORMONONET IN

AND 3,7-DIHYDROXYFLAVONE

Agnieszka Zielińska1 and Katarzyna Paradowska Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Poland 13C CP MAS NMR spectra of the flavonoids: morin, 3,7-dihydroxyflavone, tricin and isoflavones: genistein and formononetin were recorded to characterize solid-state conformations. Intramolecular hydrogen bonds forming five-, six- and seven-membered rings are present in the two morin molecules in the crystals - their 13C resonances have been assigned with the aid of the calculated shielding constants. Linear relationships between the calculated shielding constants σDFT (ppm) and chemical shifts (δCPMAS, ppm) were obtained for all studied compounds. Higher correlation coefficients suggest that the conformation with “clockwise” orientation of both OH groups is more probable in the solid 3,7-dihydroxyflavone, whereas in the solid formononetin the OH and OCH3 substituents are directed “anticlockwise”. The barrier of the rotation of phenyl ring B for morin (2’-OH, 3-OH) is higher than for tricin. Rotamers with highest energy appear at 0o and 180o, the maximum is observed at 90o (perpendicular orientation of the rings), and the structures with the lowest energy appear at 30-50o or at 130-150o. Significantly better agreement between the experimental δCPMAS and the theoretical σ values was obtained also for flavonoid molecules with the B ring torsion angle θ in the range 30-50°.

1 [email protected]

R5 R3 R2’ R3’ R4’ R5’

Morin OH OH OH H OH H Tricin OH H H OCH

3

OH OCH3

3,7–dihydroxyflavone

H OH H H H H

O

R5

HO

O

2

34

56

78

9

10

2'3'

4'

5'

6'

R2'

R3'

R4'

R5'

R3

O

R5

HO

O

2

345

6

7

89

10

2'3'

4'

5'6'

R4'

R5 R4’

Genistein OH OH Formononetin H OCH3

104

13C CP MAS NMR AND GIAO DFT CALCULATIONS OF SELECTED β-adrenolytics

Monika Zieli ńska, Dariusz Maciej Pisklak, and Jakub Konarski

Department of Physical Chemistry, Faculty of Pharmacy, Medical University of Warsaw, Poland

Β-adrenolytic drugs are widely used in the treatment of cardiac disorders like hypertention or arrhythmia. Most popular drugs include: carvedilol, atenolol, propranolol and acebutolol. All these compounds have aromatic ring linked to the 2-hydroxypropylamine chain.

O NH

OH

NH2

O

atenolol

These molecules are flexible, numerous conformations are possible due to the rotation around single C-C bonds. Since the biological activity is closely related to the structural features the studies of bioactive conformations are required. 13C CP MAS NMR were recorded on the Bruker 400 DMX spectrometer. The comparison of solid and solution state chemical shifts enabled identification of flexible fragments of molecules. DFT calculations of performed shielding constants for various conformations were helpful in the spectra assignments. Theoretical data were valuable in the characterising structural features, which can be used as descriptors of biological activity.

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