Determination of succinic acid structure in the gas phase by cm/mm spectroscopy

Estíbaliz Méndez AlijaUniversity of The Basque Country, UPV/EHU, Spain

Aerosols

Krebs Cycle

Spectrometers

LEIBNIZ UNIVERSITÄT HANNOVERGERMANY

Resolution: 3kHzRange: 2 – 26 GHzGas Phase Generation: heating (180 oC)

High Resolution Pulsed Fourier Transform Microwave Spectrometer

Rev. Sci. Instr, 67, (1996), 4072

MONASH UNIVERSITYMONASH

AUSTRALIA

Resolution: 100 – 200 kHzRange: 48 – 70 GHzGas Phase Generation: heating (180 oC)

Free Jet Stark Modulated SpectrometerJ. Mol. Struct, 190, (1988), 185-

193

UNIVERSITY OF THE BASQUE COUNTRY

BILBAOSPAIN

Resolution: 3kHzRange: 4 – 18 GHzGas Phase Generation: Ultrafast UV laser ablation system

Nd-YAG 355 nm 3 mJ/pulse

High Resolution Pulsed Fourier Transform Microwave Spectrometer

PCCP, 12, 12486 - 12493, 2010

0 6 12 180

10

20

30

40

50

Conformer

Gib

bs F

ree

Ene

rgy

(kJ

mol

-1)

Quantum Methods: MP2, M06-2X, B3LYPBasis Sets: cc-pVTZ, 6-311++g(d,p)MP2/6-311++g(d,p)

ZE

Z Z

7500 7750 8000 8250 8500 8750 9000 9250 9500 9750 10000

Frequency (MHz)

Experimental

Ab initio

Q-branch transitions

Experiment Succinic Acid

MP2 M06-2X B3LYP

6-311++G(d,p)

A / MHz 4331.326485(118) 4245.5 4360.5 4334.0

B / MHz 1194.975395(72) 1229.0 1227.5 1145.0

C / MHz 1174.979636(67) 1202.0 1195.2 1141.0

DJ / kHz 0.060057(61) 0.60 0.59 0.47

DJK / kHz -2.0175(21) -1.38 -1.67 -1.65

DK /kHz 10.2085(65) 9.06 8.34 10.76

d1 /Hz -48.75(34) -36.00 -33.60 -49.90

d2 /Hz [0.0] 5.96 -0.90 -1.63

µa / D Not observed 0.0 0.0 0.0

µb / D Observed 1.5 1.8 1.8

µc / D Not observed 0.0 0.2 0.0

N 100

/ kHz 26.9

D (O-D) ( 0.015%)

10022.0 10022.2 10022.4 10022.610195.8 10196.0 10196.2 10196.4 10196.6

10163.8 10164.0 10164.2 10164.4 8383.6 8383.8 8384.0 8384.2

Parent

13C ( 1.1%)

50,5 41,4

18O ( 0.20%)

31,3 20,2

aa/MHz -0.0484(1) bb/MHz 0.0828(1) cc/MHz -0.0334(1)

Parent Specie 13C1/13C2 13C3/13C4 18O1/18O2 (18O=C) 18O3/18O4 (18O-H) D1/D2 (16O-D)

A/MHz 4331.326485(118) 4282.82501( 35) 4330.05366(48) 4203.47337(41) 4311.49090(59) 4300.20376(33) B/MHz 1194.975395(72) 1193.43961(19) 1188.45628(31) 1181.19416(26) 1155.18372(28) 1167.72290(17) C/MHz 1174.979636(67) 1170.32301(15) 1168.76866(19) 1162.59254(18) 1137.57419(23) 1146.53197(18) DJ/kHz 0.060057(61) 0.5916( 23) 0.6005(45) 0.6080(36) 0.5689(40) 0.5783(16) DJK/kHz -2.0175(21) -2.015(13) -2.048(21) -1.832( 17) -2.042( 19) -2.154(12) DK/kHz 10.2085(65) 10.005( 22) 10.231(28) 9.250(22) 10.426(24) 10.601(19) d1/Hz -48.75(34) [-48.75] [-48.75] [-48.75] [-48.75] -43.00(87) d2/Hz [0.0] [0.0] [0.0] [0.0] [0.0] [0.0]

N 100 31 27 23 22 52 σ/kHz 26.9 9.4 19.6 12.2 14.4 13.8

aa/MHz bb/MHz cc/MHz

t (H9-O7-C4-O6) = - 179(1)º t (O6-C4-C1-C2) = 171(12)º t (C1-C2-C3-C4) = 110(14)º (t O5-C3-C2-C1) = 171(1)º (t O5-C3-O8-H10) = - 179(11)º

r(C1-C2)=1.49(82) År(C4-C1)=1.48(14) År(C3-O5)=1.23(12) Å r(C4-O7)=1.36(03) Å r(O8-H10)=0.95(13) Å

Substitution Structure

4

1 2

3

5

8

106

7

9

Ð(H9-O7-C4)=109(7)ºÐ(O6-C4-C1)=126(3)ºÐ(C1-C2-C3)=112(3)ºÐ(O5-C3-C2)= 126(3)ºÐ (O5-C3-O8)= 121(10)º

CONCLUSIONS

Gauche conformation about central carbons

Z conformations of carboxylic groups

No intramolecular hydrogen bonds

Michaela K. JahnK.P.Rajappan Nair

Prof. Jens-Uwe Grabow

Peter D. GodfreyProf. Don McNaughton

Dr. Patricia ÉcijaDr. Emilio J. Cocinero

Prof. Fernando CastañoDr. Francisco J. Basterretxea

AKNOWLEDGEMENTS