Paper

New polymeric networks from the self-assembly of silver(I) salts and

the flexible ligand 1,3-bis(4-pyridyl)propane (bpp). A systematic

investigation of the effects of the counterions and a survey of the

coordination polymers based on bpp

Lucia Carlucci,a Gianfranco Ciani,*b Davide M. Proserpiob and Silvia Rizzatob

aDipartimento di Biologia Strutturale e Funzionale, Universita dell’Insubria, Via J. H. Dunant3, 21100 Varese, Italy

bDipartimento di Chimica Strutturale e Stereochimica Inorganica, Universita di Milano, ViaG. Venezian 21, 20133 Milano, Italy. E-mail: davide@csmtbo.mi.cnr.it

Received 5th February 2002, Accepted 18th March 2002

Published on the Web 2nd April 2002

The self-assembly of polymeric networks from different Ag(I) salts and the flexible ligand 1,3-bis(4-

pyridyl)propane (bpp) has been systematically investigated in order to obtain some basic information useful for

the crystal engineering of coordination frames upon variation of the counterions. The salts AgNO3, AgBF4,

AgClO4, AgPF6, AgAsF6 and AgSbF6 have been reacted in the molar ratio Ag : bpp of 1 : 2. Though in some

cases we have observed the formation of mixtures, containing also minor amounts of the 1 : 1 adducts

[Ag(bpp)]X, the [Ag(bpp)2]X derivatives have been obtained for all the salts, and all of the isolated crystalline

products have been characterized by single-crystal X-ray analysis. Polymeric 2D and 3D networks have been

observed, exhibiting four different structural motifs: [Ag(bpp)2](NO3) (1) contains 2D layers of square meshes

that show 2-fold parallel interpenetration; compounds [Ag(bpp)2](BF4) (2) and [Ag(bpp)2](ClO4) (3) are

isomorphous and contain 2-fold interpenetrated diamondoid networks; more surprisingly, compounds

[Ag(bpp)2](PF6) (4) and [Ag(bpp)2](AsF6) (5) show a wafer-like structure containing, for the first time, 2-fold

entangled (4,4) layers alternated to simple (4,4) layers; and finally, [Ag(bpp)2](SbF6) (6) contains single 2D

layers of tessellated 4-membered rings. A brief analysis of the known coordination polymers based on the bpp

ligand is also reported, including the structure of the novel species [Cu(NO3)2(bpp)]2?2CH2Cl2, a molecular ring

that represents the unique example showing the GG conformation for the bpp ligands.

Introduction

Current interest for the crystal engineering of coordinationpolymers1 derives from their potential applications as zeolite-like materials for molecular selection, and ion exchange andcatalysis, but also from the intriguing variety of architecturesand the new topologies and intertwining phenomena observedin these species. Metal-directed supramolecular self-assemblyhas produced fascinating results in the deliberate constructionof molecular interlocked/intertwined species (like rotaxanes,catenanes, knots and helicates),2 molecular rings and cages3

and extended 2D and 3D networks.4 Conformationally flexibleligands are typical building elements for the assembly of finitearchitectures, while essentially rigid, rod-like organic units areusually employed to connect the metal centres into extendednetworks. However, there is an increasing number of recentlycharacterized, interesting, interwoven frames incorporatingmetal ions and flexible-chain linkers.5

Extending our previous work on the self-assembly ofcoordination networks based on AgI salts of non-coordinatinganions and bidentate aromatic N-donor bases,6 we are studyingthe reactivity of the flexible 1,3-bis(4-pyridyl)propane ligand(bpp), which can assume different conformations (TT, TG, GGand GG’, see Scheme 1) that display quite different N-to-Ndistances. The free rotation of the pyridyl rings, moreover,generates different configurations: for instance, in the TT con-formation the two pyridyl groups show a variety of rotationsthat include the limiting situations with both rings coplanar orboth perpendicular with respect to the molecular plane.We have already observed that bpp reacts with Ag(CF3SO3)

to give noteworthy products, including an infinite double-helix and a 1D tubular species comprised of rings threaded byfree bpp molecules in a pseudorotaxane-like fashion.7 Other

interesting products of bpp were obtained using Cu21 centres,as [Cu5(bpp)8(SO4)4(EtOH)(H2O)5](SO4)?EtOH?25.5H2O, asponge-like material consisting of two-dimensional four-connected layers and one-dimensional ribbons of rings,entangled to give a supramolecular catenated 3D architecture,8

and a series of remarkable networks assembled with CuCl2containing 1D, 2D and 3D motifs that can be interconverted.9

We report here on the reactions of different silver salts withbpp and describe the polymeric products obtained, all con-taining cationic frames with the same formula [Ag(bpp)2]

1. Acomparative discussion of the structural features observed inall the other known polymeric products of bpp is also reported.In this concern we describe the new dinuclear species

Scheme 1

DOI: 10.1039/b201288j CrystEngComm, 2002, 4(22), 121–129 121

This journal is # The Royal Society of Chemistry 2002

[Cu(NO3)2(bpp)]2?2CH2Cl2, that represents the unique case inwhich the bpp ligands exhibit the GG conformation.

Results

The reactions of silver salts with bpp have already affordedinteresting coordination polymers. We have reported on theproducts obtained from silver triflate,7 and, successively, theone-dimensional species [Ag(bpp)]X (X ~ NO3

2,10 ClO42,11

PF62,11) have been characterized by others.

We describe here the novel products from the reactions of thesalts AgNO3, AgBF4, AgClO4, AgPF6, AgAsF6 and AgSbF6

with bpp in the molar ratio Ag : bpp of 1 : 2. The new[Ag(bpp)2]X species have been obtained in good yieldsfollowing the same methods used for previously reportedAg(I) polymers with bis(4-pyridyl) ligands, i.e. by slow diffu-sion of a solution of the bpp ligand in CH2Cl2 into a solution ofthe silver salt in ethanol. In some cases mixtures were obtainedwhich also contained smaller amounts of the 1 : 1 adducts[Ag(bpp)]X. This was observed for X ~ NO3

2, BF42 and

AsF62; their crystals were separated under the microscope and

recognized by X-ray diffraction, by comparison with thereported structures.10,12

The crystals of the novel [Ag(bpp)2]X adducts, air-stable forsignificant periods of time, have been investigated by single-crystal X-ray analysis. All the products contain cationic[Ag(bpp)2]

1 frames based on more or less distorted tetrahedralAg(I) centres, but exhibit two distinct types of motif: two-dimensional square layers and three-dimensional diamondoidnets (see Table 1). The numbering of the products follows theincreasing dimensions of the counterions.

Two-dimensional networks

The crystal structures of compounds 1, 4, 5 and 6 are allcomprised of 2D layers with (4,4) topology. However, thesupramolecular organization of the layers is quite different,with three distinct cases: (a) single layers (6); (b) 2-fold layersinterpenetrated in a parallel fashion (1); and (c) the alternationof the two above motifs in the same crystal (4 and 5).

Single layers

Compound 6 contains tessellated single (4,4) layers illustratedin Fig. 1. The layers are undulated and the four-memberedrings show Ag…Ag edges of 13.00 A. The ligands display theTT conformation (N-to-N of 9.20 A). The silver atoms exhibita distorted tetrahedral geometry (Ag–N 2.33 A, N–Ag–N 101–129u). The layers are exactly superimposed along the directionof the tetragonal c-axis. A side view of the stacking is shown inFig. 2. Each layer interacts with its nearest neighbouring onesvia C–H…p contacts13 involving all the pyridyl groups, whichact as both donors and acceptors as shown in Fig. 3 (H…ringcentroid 2.8 A). Large channels are generated, running along c,that are occupied by disordered anions and ethanol molecules(free voids for the solvents up to 24% of the cell volume).14 TheSbF6

2 anions are statistically distributed on two rows disposedalong c inside each channel.

Two-fold parallel interpenetration

[Ag(bpp)2](NO3) (1) contains 2D layers of square meshes withAg…Ag edges of 14.20–14.29 A. A single undulated layer isshown in Fig. 4. The coordination geometry of the silver atomsis distorted tetrahedral (Ag–N 2.31–2.40 A, N–Ag–N 99–131u).Two such layers exhibit parallel interpenetration as illustratedin Fig. 5. This is one of the possible modes of parallelinterpenetration of square layers enumerated by Batten andRobson.15 These entangled sheets are associated in pairs alongthe a-axis via strong p–p interactions involving the pyridyl ringsof adjacent layers (see Fig. 6, top; plane–plane distance 3.55A).16 The resulting complex 2D arrays stack along the a

Table 1 List of the silver polymers

Compound Structure type Ligand conformation N-to-N/A

[Ag(bpp)2](NO3) (1) 2D (4,4) layers 2-fold interpenetrated TT 10.02–10.17[Ag(bpp)2](BF4) (2) 3D diamondoid nets 2-fold interpenetrated GG’ 6.68[Ag(bpp)2](ClO4) (3) 3D diamondoid nets 2-fold interpenetrated GG’ 6.69[Ag(bpp)2](PF6) (4) 2D (4,4) layers single and 2-fold interpenetrated TT 9.83–9.90[Ag(bpp)2](AsF6) (5) 2D (4,4) layers single and 2-fold interpenetrated TT 9.85–9.86[Ag(bpp)2](SbF6)?0.5EtOH (6) 2D (4,4) single layers TT 9.20

Fig. 1 View of a layer in 6 (down the c-axis).

Fig. 2 Side view of stacking of the layers in 6.

122 CrystEngComm, 2002, 4(22), 121–129

direction, leaving interlayer voids that are occupied by thenitrate anions, as illustrated in Fig. 6 (bottom).

The wafer-like structures of compounds 4 and 5

These two species are isomorphous and are comprised of 2Dundulated layers of rhombic meshes (Ag…Ag edges of 13.58 A)shown in Fig. 7. There are two independent but quite similarsuch layers in the crystals, A and B, in the ratio 1 : 2. In bothlayers the coordination of the silver atoms is highly distortedtetrahedral. This is particularly evident in layers of type A (seeFig. 7): the geometry is intermediate between tetrahedral andsaw-horse like, with one N–Ag–N angle somewhat larger (ca.140u) and the opposite one somewhat smaller (ca. 89u) than theother four (range 100–108u). While the A layers are single,

Fig. 3 Two views that illustrate the C–H…p interactions involvingadjacent layers in 6.

Fig. 4 Single (4,4) layer in 1. Click image or here to access a 3Drepresentation.

Fig. 5 Two-fold interpenetration in 1 illustrated by a top view (downthe a-axis) and the two corresponding side views.

Fig. 6 Stacking of the 2-fold interpenetrated layers (top, two coloursare used for alternating pairs; click image or here to access a 3Drepresentation), and the channels containing the NO3

2 anions (bottom;click image or here to access a 3D representation).

CrystEngComm, 2002, 4(22), 121–129 123

those of type B are 2-fold interpenetrated in a parallelfashion,1c as illustrated in Fig. 8. The entangled BB array(Fig. 8, bottom) is topologically equivalent to the interpene-trated layer in compound 1.15 A proportion of the anions(ordered, 1/3) is embedded inside these 2D (BB) arrays andseem to have some templating role. The other anions (2/3) arelocated in the rhombic meshes of the A layers and showorientational disorder. The two different structural motifsalternate in the crystals, stacking in the c direction with asequence A(BB)A(BB) (see Fig. 9). The existence of differentstructural motifs in the same structure is rather rare. We havepreviously described another wafer-like structure containingtwo different types of Ag–pyrazine layers,6c but neither motifwas interpenetrated.

Three-dimensional diamondoid networks

The two derivatives [Ag(bpp)2](BF4) (2) and [Ag(bpp)2](ClO4)(3) are isomorphous and contain diamondoid frameworks. Asingle adamantanoid cage is illustrated in Fig. 10 (for 2); itexhibits equal Ag…Ag edges that are 9.54 A for 2 and 9.63 Afor 3. Two independent, equivalent networks are interpene-trated within the crystals; two cages (one for each net) displacedalong the tetragonal c-axis (by c/2) are shown in Fig. 11. Thetwo networks, however, are not simply related by a translation,as in the so-called ‘normal mode’1c,17 of interpenetration fordiamondoid frames, but are generated by a c glide plane(i.e. reflection plus translation). While the ‘normal mode’ isdominant and many examples within diamondoid coordination

Fig. 7 Single layers of type A in 5.

Fig. 8 Comparison of the alternating single (top) and 2-fold inter-penetrated (bottom) layers in 5. Only one model for the disorderedanions in the A layers is shown for clarity.

Fig. 9 View of the stacking of the two 2D motifs in 5.

124 CrystEngComm, 2002, 4(22), 121–129

polymers have been reported,1c,17 ranging from 2-fold to 10-fold,18 the interpenetration observed in compounds 2 and 3 isunusual.19 However, the difference arises only from thedispositions of the bridging ligands and in a strict topologicalsense, i.e. considering only the Ag metal centres, the inter-penetration appears normal (see Fig. 12). The adamantanoidcages exhibit maximum dimensions (corresponding to thelongest intracage Ag…Ag distances) of 20.79 6 20.79 624.30 A for 2 and 20.84 6 20.84 6 24.78 A for 3. Thesepolymers are unique within the species here reported in thatthey exhibit a GG’ conformation of the bpp ligands. Thisconformation leads to an N-to-N distance somewhat shorter(6.68 A) than in the TT or TG conformations of the ligand(see later). As a consequence, the degree of interpenetration islow when compared with other similar [AgL2]X diamondoidspecies with bis(4-pyridyl) ligands, i.e. 4-fold interpenetrationwith L ~ 4,4’-bipyridyl, X ~ triflate,6a PF6

2,20 SbF62;20

and 6-fold interpenetration with L ~ bis(4-pyridyl)ethane,X ~ triflate, PF6

2, BF42.20

The diagram of the cationic frame viewed down the c-axis(Fig. 11, bottom) also shows that the ligands, owing to theirconformation, almost fill the ‘anionic channels’ running alongthe direction of interpenetration and which are usuallyoccupied by the anions. As a consequence, the anions areplaced midway between Ag centres along c, forming Ag/X/Ag/X rows. The Ag(I) cations display a tetrahedral geometry (Ag–N 2.32 A; N–Ag–N 109–110u). The two interpenetrated sets areassociated through p–p interactions involving the pyridyl rings(plane–plane distance 3.56 A).16

Fig. 10 Single adamantanoid cage in 2 shown in a side view (top) anddown the tetragonal axis (bottom).

Fig. 11 Two views of the interpenetration of two adamantanoid cagesin 2. Click the lower image or here to access a 3D representation.

Fig. 12 Schematic view of the two interpenetrating nets in 2 and 3.

CrystEngComm, 2002, 4(22), 121–129 125

Discussion

Though compounds 1–6 contain cationic frames with the samegeneral formula [Ag(bpp)2]

1 their structures exhibit quite dif-ferent features. We have previously observed the possibleexistence of supramolecular isomerism involving the inter-conversion of 2D (4,4) layers and 3D diamondoid nets usingthe same metal salt, both with rigid6a or flexible ligands.9 Subtlefactors, difficult to rationalize, seem responsible for this net-work isomerism and it is not surprising that in the presence ofdifferent anions, with various dimensions and donor proper-ties, different structures can result. We can only observe (seeTable 1) that different anions also induce different ligand con-formations: TT for the 2D layers and GG’ for the diamondoidnets.We have examined the known polymeric species containing

the bpp ligand (listed in Table 2). These include a variety ofstructural types, due to the presence of metals with differentcoordination geometries, different metal to ligand ratios and, insome cases, ancillary ligands and/or particular coordinatinganions.Within compounds with a metal : bpp ratio of 1 : 1 (Table 2,

Nos. 1–6, 16, 18) the most common species are 1D simplechains based on diagonal AgI centres. Only their supramole-cular organization can extend the dimensionality of the arrayvia argentophilic Ag…Ag interactions (No. 4), or can result inunusual infinite motifs, as double helices (No. 5).Many products show an M(bpp)2 stoichiometry, with mono-

or di-valent metal ions, in coordination geometries 4 or 6,respectively. Three are the principal motifs: (i) 1D ribbons ofrings (Nos. 8, 9); (ii) 2D (4,4) layers (Nos. 11–14, and theabove-described silver compounds 1, 4–6); and (iii) 3Ddiamondoid nets (No. 20, and the above-described compounds2 and 3). The versatility of the flexible bpp ligand is confirmedby the finding of quite peculiar species, as with Nos. 7, 15–19.The compounds listed in Tables 1 and 2 show that the bpp

ligands assume three out of the possible four conformationsillustrated in Scheme 1 (i.e. TT, TG and GG’). The N-to-Ndistances reported therein for these conformations (obtainedfrom an analysis of all the structural data) show the orderTTw TGwGG’ and span distinct and almost non-overlappingintervals. The particularly wide range observed for GG’ here isdue to the higher sensitivity of the N-to-N distance to the smalldeviations of the torsion angles from ideality.24 The fourthconformation, GG, is peculiar in that it imposes a uniquelyshort contact to the bridged metals. We describe here the firstcase of a species exhibiting this conformation, namely thedinuclear compound [Cu(NO3)2(bpp)]2?2CH2Cl2 (7). It consistsof molecular rings, with two Cu21 metal ions connected by twobpp ligands that display an N-to-N distance of 3.87 A (seeFig. 13). The two metals are also asymmetrically bridged bytwo g1-nitrate anions and their coordination sphere iscompleted by a strongly asymmetric g2-nitrate anion, thusresulting in a Jahn–Teller trans elongated octahedral geometry.The subtended Cu…Cu contact is 3.90 A. The ligands exhibittheir pyridyl rings in facing positions, with a small dihedralangle of 13u. Curiously, compound 7 has a non-polymericstructure, a difference from the 2D network of square meshes in[Cu(bpp)2(NO3)2]?0.25H2O obtained by Plater et al.21e Thedifference can probably be ascribed to the use of a differentsolvent system (EtOH/H2O for the 2D species instead ofCH2Cl2/EtOH for 7).

Experimental

Materials

All reagents and solvents employed were commercially avail-able high-grade purity materials (Aldrich Chemicals), used assupplied, without further purification. Elemental analyses were T

able

2Examplesofmetal–bppcoordinationpolymers

No.

Form

ula

Dim

ension

Network

Conform

ation

N-to-N

/ARef.

1[A

g(bpp)](N

O3)

1D

Sinusoidalchains

TG

8.79

10

2[A

g(bpp)](C

F3SO

3)?(EtO

H)

1D

Sinusoidalchains

TT

9.24

73

[Ag(bpp)](C

lO4)

1D

Sinusoidalchains

TT

9.47–9.57

11

4[A

g(bpp)](PF6)

1D

Sinusoidalchains

TT

9.70

11

5[A

g(bpp)](C

F3SO

3)

1D

Double

helix

GG’

7.67

76

[Cu(bpp)(2,2’-b

ipyridyl)(EtO

H)](BF4) 2

1D

Festoonchains

TT

9.11

21a

7[A

g2(bpp) 4](CF3SO

3) 2(bpp)

1D

Tubularpolymer

TT,TG

9.24,8.63

78

[Ni(bpp) 2(H

2O) 2](NO

3) 2(bpp)(H

2O)

1D

Ribbonsofrings

TG,GG’

8.60–8.67,8.38

21b

9[M

(bpp) 2(H

2O) 2](ClO

4) 2(bpp)(H

2O)(M

~Ni,Co,Cd)

1D

Ribbonsofrings

TG

8.63–8.69

21c,d

10

[M(bpp) 3Cl 2]?2H

2O

(M~

Cu,Ni,Co,Cd)

1D

Zig-zagchainswithdanglingligands

TT,TG

9.92,9.16

911

[Cu(bpp) 2(X

) 2]?0.25H

2O

(X~

NO

3,ClO

4)

2D

Single

(4,4)layers

TT,GG’

9.65–9.70,7.85–8.61

21e

12

[Mn2(bpp) 4(N

CS) 4]

2D

(4,4)Layers2-fold

TT,TG,GG’

9.46,9.03,8.06–8.33

21f

13

[Cd2(bpp) 4(N

O3) 3(H

2O)]?(NO

3)

2D

(4,4)Layers2-fold

TT,GG’

9.61–9.63,7.82–7.86

21g

14

[Cu(bpp) 2Cl 2]?2.75H

2O

2D

(4,4)Layers2-fold

withinclined

interpenetration

TT,TG

9.19–9.38,8.64–8.93

9

15

[Cd2(bpp) 3(N

O3) 4]

2D

(3,6)Layers4-fold

TT,TG

9.26–9.53,8.91

21b

16

[Zn3(O

H) 3(bpp) 3](NO

3) 3?8.67H

2O

2D

Self-interpenetrated

TT

9.69–9.82

21h,22

17

[Cd2(bpp) 3(SO

4) 2(H

2O) 2.7]?4.5H

2O

3D

Complextopology

TT,TG

9.29,8.57–9.02

21g

18

[Cd(bpp)(NCS) 2]

3D

42?6

3?10

TG

8.66

21d,23

19

[Cu5(bpp) 8(SO

4) 4(EtO

H)(H

2O) 5](SO

4)?EtO

H?25.5H

2O

3D

(4,4)Layersinterpenetratedbyribbons

ofrings

TT,TG

9.26–10.01,8.71–9.10

8

20

[M(bpp) 2Cl]Cl?1.5H

2O

(M~

Cu,Ni,Co,Cd)

3D

Diamondoid

4-fold

interpenetrated

TT

9.80–9.83

9

126 CrystEngComm, 2002, 4(22), 121–129

carried out at the Microanalytical Laboratory of the Universityof Milan.

Synthesis of the silver polymers

All of the compounds were prepared by reacting at roomtemperature the silver salts (AgNO3, AgBF4, AgClO4, AgPF6,AgAsF6, AgSbF6), dissolved in ethanol, with dichloromethanesolutions of the bpp ligand in molar ratio 1 : 2. For example,[Ag(bpp)2](BF4) has been obtained on layering an ethanolicsolution (4 mL) of AgBF4 (0.0236 g, 0.121 mmol) on a solutionof the bpp ligand (0.048 g, 0.242 mmol) in dichloromethane(4 mL). The mixtures were left in the dark for some days andthen allowed to concentrate by slow evaporation of the solventin air. The compounds were obtained with yields of 30–50%;when mixtures of products were formed the crystalline mater-ials were separated under the microscope and submitted to theanalyses. The elemental analyses are as follows. [Ag(bpp)2]-(NO3) (1), Anal. calc. for C26H28AgN5O3: C 55.13, H 4.98, N12.37; Found: C 54.90, H 4.65, N 12.01%. [Ag(bpp)2](BF4) (2),Anal. calc. for C26H28AgBF4N4: C 52.82, H 4.77, N 9.48;Found: C 52.31, H 4.45, N 9.37%. [Ag(bpp)2](ClO4) (3), Anal.calc. for C26H28AgClN4O4: C 51.71, H 4.67, N 9.28; Found: C51.03, H 4.12, N 9.14%. [Ag(bpp)2](PF6) (4), Anal. calc. forC26H28AgF6N4P: C 48.09, H 4.35, N 8.63; Found: C 47.96, H4.17, N 8.98%. [Ag(bpp)2](AsF6) (5), Anal. calc. for C26H28-AgAsF6N4: C 45.04, H 4.07, N 8.08; Found: C 44.99, H 4.00, N8.01%. [Ag(bpp)2](SbF6) (6), Anal. calc. for C27H31AgF6-N4O0.50Sb: C 50.56, H 4.87, N 8.74; Found: C 50.21, H 4.53, N8.95%.

Synthesis of the complex [Cu(NO3)2(bpp)]2?2CH2Cl2

The bpp ligand (0.0445 g, 0.224 mmol) was dissolved in CH2Cl2(4 mL) and layered on an ethanolic solution (4 mL) of thecopper salt Cu(NO3)2?3H2O (0.0271 g, 0.112 mmol). Thereaction mixture was maintained at 4 uC for some days andthen it was allowed to reach room temperature and to concen-trate by slow evaporation of the solvent in the air. [Cu(NO3)2-(bpp)]2?2CH2Cl2 (7), Anal. calc. for C28H32Cl4Cu2N8O12: C35.71, H 3.43, N 11.90; Found: C 36.65, H 3.58, N 13.12%. Apartial loss of the solvated dichloromethane is observed.

Crystallography

The crystal data for all the compounds are listed in Table 3 andselected bond distances and angles in Table 4. The datacollections were performed at 293 K (Mo-Ka, l ~ 0.71073 A)on an Enraf-Nonius CAD4 diffractometer, by the v-scanmethod, within the limits 3v hv 24u (4, 7), 3v hv 25u (1, 5),3 v h v 26u (2, 3), 3 v h v 28u (6). An empirical absorptioncorrection was applied (y-scan). The structures were solved by

Fig. 13 The dinuclear complex 7.

Table

3Crystallographic

data

forcompounds1–7a

Parameter

12

34

56

7

Form

ula

C26H

28AgN

5O

3C26H

28AgBF4N

4C26H

28AgClN

4O

4C78H

84Ag3F18N

12P3

C78H

84Ag3As 3F18N

12

C27H

31AgF6N

4O

0.50Sb

C28H

32Cl 4Cu2N

8O

12

M566.40

591.20

603.84

2079.94

1948.09

763.18

941.50

Crystalsystem

Monoclinic

Tetragonal

Tetragonal

Monoclinic

Monoclinic

Tetragonal

Monoclinic

Space

group

C2/c

(no.15)

I41/acd

(no.142)

I41/acd

(no.142)

C2(no.5)

C2(no.5)

P421m

(no.113)

P21/c

(no.14)

a/A

25.278(8)

14.703(4)

14.734(2)

22.988(4)

23.073(7)

18.389(2)

11.576(2)

b/A

14.288(6)

14.703(4)

14.734(2)

14.452(4)

14.339(6)

18.389(3)

14.919(3)

c/A

14.198(6)

24.304(4)

24.784(4)

12.882(5)

12.784(2)

5.202(1)

11.879(2)

b/u

99.97(3)

90

90

96.20(2)

96.43(2)

90

109.89(2)

U/A

35050(3)

5254(2)

5380.4(13)

4255(2)

4203(2)

1759.1(5)

1929.2(6)

Z8

88

22

22

Dc/g

cm23

1.490

1.495

1.491

1.624

1.539

1.441

1.621

m(M

o-K

a)/mm

21

0.835

0.817

0.887

1.930

0.839

1.377

1.447

Reflectionscollected

4597

2507

1317

3644

3987

1272

3176

Independentreflections,Rint

4415,0.0480

1293,0.1078

1317

3487,0.0701

3819,0.0551

1272

3023,0.0644

Observed

reflections[F

w4s(F)]

2362

453

431

1705

1810

621

1273

R1[F

w4s(F)]

0.0467

0.0359

0.0353

0.0882

0.0898

0.0487

0.0555

wR2(alldata)

0.1444

0.0842

0.0993

0.2594

0.2507

0.1573

0.1839

aClick

hereforfullcrystallographic

data

(CCDC

178924–178930).

CrystEngComm, 2002, 4(22), 121–129 127

direct methods (SIR97)25 and refined by full-matrix, least-squares (SHELX-97),26 with WINGX interface.27 Anisotropicthermal parameters were assigned to all the non-hydrogenatoms but not to the disordered ones in some of the structures,which were refined isotropically. For compounds 4 and 5,acentric space groups were found and, to keep an acceptableparameter/observable ratio, isotropic thermal parameters wereassigned to all light atoms. Orientationally disordered anionswere found in compounds 4 and 5, and suitable disordermodels were refined in both cases. Compound 6 containschannels full of disordered ethanol molecules and the SbF6

2

anions occupy a special position (e in Wyckoff notation) withsite occupancy 50%. The handedness of the crystals of 4, 5 and6 were determined by testing the two enantiomeric models witha final refined Flack parameter of 0.10(11), 0.0(2) and 0.00(14),respectively. All the diagrams were obtained using theSCHAKAL99 program.28

Acknowledgements

This work was supported by MURST within the project ‘SolidSupermolecules’ 2000–2001.

Notes and references

1 (a) B. F. Hoskins and R. Robson, J. Am. Chem. Soc., 1990, 112,1546; (b) R. Robson, B. F. Abrahams, S. R. Batten, R. W. Gable,B. F. Hoskins and J. Liu, in Supramolecular Architecture, T. Bein,ed., ACS publications, Washington, 1992, ch. 19; (c) S. R. Battenand R. Robson, Angew. Chem., Int. Ed., 1998, 37, 1461;(d) C. L. Bowes and G. A. Ozin, Adv. Mater., 1996, 8, 13;(e) A. J. Blake, N. R. Champness, P. Hubberstey, W. S. Li,

M. A. Withersby and M. Schroder, Coord. Chem. Rev., 1999, 183,117; (f) A. N. Khlobystov, A. J. Blake, N. R. Champness,D. A. Lemenovskii, A. G. Majouga, N. V. Zyk and M. Schroder,Coord. Chem. Rev., 2001, 222, 155; (g) P. J. Hagrman, D. Hagrmanand J. Zubieta, Angew. Chem., Int. Ed., 1999, 38, 2639;(h) M. Eddaoudi, D. B. Moler, H. L. Li, B. L. Chen, T. M.Reineke,M. O’Keeffe and O.M. Yaghi,Acc. Chem. Res., 2001, 34,319; (i) M. O’Keeffe, M. Eddaoudi, H. L. Li, T. Reineke andO. M. Yaghi, J. Solid State Chem., 2000, 152, 3; (j) M. Munakata,L. P. Wu and T. Kuroda-Sowa, Adv. Inorg. Chem., 1999, 46, 173;(k) B. Moulton andM. J. Zaworotko,Chem. Rev., 2001, 101, 1629.

2 Comprehensive Supramolecular Chemistry, J.-M. Lehn, ed.,Pergamon Press, Oxford, 1995.

3 S. Leininger, B. Olenyuk and P. J. Stang, Chem. Rev., 2000, 100,853; M. Fujita, Acc. Chem. Res., 1999, 32, 53; M. Fujita, Struct.Bonding, 2000, 96, 177; G. F. Swiegers and T. J. Malefetse, Chem.Rev., 2000, 100, 3483; R. V. Slone, K. D. Benkstein, S. Belanger,J. T. Hupp, I. A. Guzei and A. L. Rheingold, Coord. Chem. Rev.,1998, 171, 221; J. A. R. Navarro and B. Lippert, Coord. Chem.Rev., 2001, 222, 219.

4 For recent papers, see, for example: J. Kim, B. L. Chen,T. M. Reineke, H. L. Li, M. Eddaoudi, D. B. Moler,M. O’Keeffe and O. M. Yaghi, J. Am. Chem. Soc., 2001, 123,8239; M. Eddaoudi, J. Kim, J. B. Wachter, H. K. Chae,M. O’Keeffe and O. M. Yaghi, J. Am. Chem. Soc., 2001, 123,4368; B. Moulton, J. J. Lu and M. J. Zaworotko, J. Am. Chem.Soc., 2001, 123, 9224; S. A. Bourne, J. J. Lu, A. Mondal,B. Moulton and M. J. Zaworotko, Angew. Chem., Int. Ed., 2001,40, 2111; A. J. Blake, M. T. Brett, N. R. Champness,A. N. Khlobystov, D. L. Long, C. Wilson and M. Schroder,Chem. Commun., 2001, 2258; D. L. Long, A. J. Blake,N. R. Champness, C. Wilson and M. Schroder, J. Am. Chem.Soc., 2001, 123, 3401; L. Carlucci, G. Ciani, D. M. Proserpio andS. Rizzato, Chem. Commun., 2000, 1319; L. Carlucci, G. Ciani,D. M. Proserpio and S. Rizzato, Chem. Commun., 2001, 1198;Z. T. Xu, Y. H. Kiang, S. Lee, E. B. Lobkovsky and N. Emmott,

Table 4 Selected bond distances (A) and angles (u) for compounds 1–7

Compound 1 N(3)–Ag(2)–N(5) 95.3(6)Ag–N(1) 2.307(5) N(4)–Ag(2)–N(5) 102.0(7)Ag–N(2) 2.315(5)Ag–N(3) 2.370(5) Compound 5Ag–N(4) 2.399(5) Ag(1)–N(2) 6 2 2.26(2)

Ag(1)–N(1) 6 2 2.48(2)N(1)–Ag–N(2) 130.8(2) Ag(2)–N(6) 2.25(2)N(1)–Ag–N(3) 106.2(2) Ag(2)–N(3) 2.29(2)N(2)–Ag–N(3) 101.4(2) Ag(2)–N(4) 2.34(2)N(1)–Ag–N(4) 101.9(2) Ag(2)–N(5) 2.41(2)N(2)–Ag–N(4) 99.0(2)N(3)–Ag–N(4) 119.0(2) N(1)–Ag(1)–N(1) 88.3(8)

N(2)–Ag(1)–N(2) 138.3(9)Compound 2 N(2)–Ag(1)–N(1) 6 2 108.2(6)Ag–N(1) 6 4 2.317(4) N(2)–Ag(1)–N(1) 6 2 101.4(7)

N(6)–Ag(2)–N(3) 133.6(8)N(1)–Ag–N(1) 6 2 110.9(2) N(6)–Ag(2)–N(4) 106.9(7)N(1)–Ag–N(1) 6 4 108.77(9) N(3)–Ag(2)–N(4) 106.9(6)

N(6)–Ag(2)–N(5) 106.9(6)Compound 3 N(3)–Ag(2)–N(5) 95.4(6)Ag–N(1) 6 4 2.325(4) N(4)–Ag(2)–N(5) 103.0(7)

N(1)–Ag–N(1) 6 2 110.5(2) Compound 6N(1)–Ag–N(1) 6 4 108.9(1) Ag–N(1) 6 4 2.325(7)

Compound 4 N(1)–Ag–N(1) 6 4 100.8(1)Ag(1)–N(2) 6 2 2.25(2) N(1)–Ag–N(1) 6 2 128.7(4)Ag(1)–N(1) 6 2 2.48(2)Ag(2)–N(6) 2.27(2) Compound 7Ag(2)–N(3) 2.32(2) Cu(1)–N(1) 1.980(7)Ag(2)–N(4) 2.35(2) Cu(1)–N(2) 1.977(7)Ag(2)–N(5) 2.42(2) Cu(1)–O(12) 2.019(6)

Cu(1)–O(21) 2.025(6)N(1)–Ag(1)–N(1) 89.6(8)N(2)–Ag(1)–N(2) 141.3(9) N(1)–Cu(1)–N(2) 176.2(3)N(2)–Ag(1)–N(1) 6 2 99.9(6) N(1)–Cu(1)–O(12) 88.2(3)N(2)–Ag(1)–N(1) 6 2 107.4(5) N(2)–Cu(1)–O(12) 89.7(3)N(6)–Ag(2)–N(3) 133.6(7) N(1)–Cu(1)–O(21) 90.2(2)N(6)–Ag(2)–N(4) 106.8(6) N(2)–Cu(1)–O(21) 91.3(3)N(3)–Ag(2)–N(4) 107.5(6) O(12)–Cu(1)–O(21) 169.5(2)N(6)–Ag(2)–N(5) 107.0(6)

128 CrystEngComm, 2002, 4(22), 121–129

J. Am. Chem. Soc., 2000, 122, 8376; C. J. Kepert, T. J. Prior andM. J. Rosseinsky, J. Am. Chem. Soc., 2000, 122, 5158; S. R. Batten,A. R. Harris, P. Jensen, K. S. Murray and A. Ziebell, J. Chem.Soc., Dalton Trans., 2000, 3829; O. R. Evans andW. B. Lin, Chem.Mater., 2001, 13, 3009; E. Lee, J. Kim, J. Heo, D. Whang andK. Kim, Angew. Chem., Int. Ed., 2001, 40, 399; M. B. Zaman,M. D. Smith and H. C. zur Loye, Chem. Commun., 2001, 2256;D. Hagrman, P. J. Hagrman and J. Zubieta, Angew. Chem., Int.Ed., 1999, 38, 3165; I. Goldberg, Chem.-Eur. J., 2000, 6, 3863.

5 See, for example: C. X. Ren, H. L. Zhu, G. Yang and X. M. Chen,J. Chem. Soc., Dalton Trans., 2001, 85; M. L. Tong, X. M. Chen,B. H. Ye and L. N. Ji, Angew. Chem., Int. Ed., 1999, 38, 2237;L. Carlucci, G. Ciani, P. Macchi, D. M. Proserpio and S. Rizzato,Chem.-Eur. J., 1999, 5, 237; M. J. Plater, M. Foreman, T. Gelbrichand M. B. Hursthouse, Cryst. Eng., 2001, 4, 319; D. M. Ciurtin,Y. B. Dong, M. D. Smith, T. Barclay and H. C. zur Loye, Inorg.Chem., 2001, 40, 2825.

6 (a) L. Carlucci, G. Ciani, D. M. Proserpio and A. Sironi, J. Chem.Soc., Chem. Commun., 1994, 2755; (b) L. Carlucci, G. Ciani,D. M. Proserpio and A. Sironi, Inorg. Chem., 1995, 34, 5698;(c) L. Carlucci, G. Ciani, D. M. Proserpio and A. Sironi, Angew.Chem., Int. Ed. Engl., 1995, 34, 1895; (d) L. Carlucci, G. Ciani,D. M. Proserpio and A. Sironi, J. Am. Chem. Soc., 1995, 117,4562; (e) L. Carlucci, G. Ciani, D. M. Proserpio and A. Sironi,Chem. Commun., 1996, 1393; (f) L. Carlucci, G. Ciani, D. M.Proserpio and A. Sironi, Inorg. Chem., 1998, 37, 5941; (g) L.Carlucci, G. Ciani and D. M. Proserpio, Angew. Chem., Int. Ed.,1999, 38, 3488; (h) L. Carlucci, G. Ciani and D. M. Proserpio,Chem. Commun., 1999, 449.

7 L. Carlucci, G. Ciani, D. W. von Gudenberg and D. M. Proserpio,Inorg. Chem., 1997, 36, 3812.

8 L. Carlucci, G. Ciani, M. Moret, D. M. Proserpio and S. Rizzato,Angew. Chem., Int. Ed., 2000, 39, 1506.

9 L. Carlucci, G. Ciani, M. Moret, D. M. Proserpio and S. Rizzato,Chem. Mater., 2002, 14, 12.

10 S. R. Batten, J. C. Jeffery and M. D. Ward, Inorg. Chim. Acta,1999, 292, 231.

11 L. Pan, E. B. Woodlock, X. Wang, K.-C. Lam and A. L.Rheingold, Chem. Commun., 2001, 1762.

12 The polymeric species [Ag(bpp)](BF4) and [Ag(bpp)](AsF6)are isomorphous with the reported species [Ag(bpp)](ClO4) and[Ag(bpp)](PF6), respectively (see ref. 11).

13 M. Nishio, M. Hirota and Y. Umezawa, The CH/p Interaction.Evidence, Nature and Consequences, Wiley, New York, 1998;Z. Ciunik and G. R. Desiraju, Chem. Commun., 2001, 703.

14 A. L. Speck, PLATON, A Multipurpose Crystallographic Tool,

Utrecht University, Utrecht, The Netherlands, 1999. An analysisof the holes was performed with this program.

15 See Fig. 18 in ref. 1c.16 C. Janiak, J. Chem. Soc., Dalton Trans., 2000, 3885.17 S. R. Batten, CrystEngComm, 2001, 18.18 L. Carlucci, G. Ciani, D. M. Proserpio and S. Rizzato, Chem.-Eur.

J., 2002, 8, 1519.19 A similar situation as been observed in the 4-fold diamondoid

species [CuCl2(bpp)2] reported in ref. 9.20 L. Carlucci, G. Ciani, D. M. Proserpio and S. Rizzato,

unpublished results.21 (a) L. Carlucci, G. Ciani, A. Gramaccioli, D. M. Proserpio and

S. Rizzato, CrystEngComm, 2000, 29; (b) C. V. K. Sharma,R. J. Diaz, A. J. Hessheimer and A. Clearfield, Cryst. Eng., 2000,3, 201; (c) M. J. Plater, M. R. St. J. Foreman, T. Gelbrich andM. B. Hursthouse, Inorg. Chim. Acta, 2001, 318, 171;(d) M. J. Plater, M. R. St. J. Foreman and J. M. S. Skakle,Cryst. Eng, 2001, 4, 293; (e) M. J. Plater, M. R. St. J. Foreman andA. M. Z. Slawin, J. Chem. Res. (S), 1999, 74; (f) M. J. Plater,M. R. St. J. Foreman, R. A. Howie and J. M. S. Skakle, Inorg.Chim. Acta, 2001, 318, 175; (g) M. J. Plater, M. R. St. J. Foreman,T. Gelbrich, S. J. Coles and M. B. Hursthouse, J. Chem. Soc.,Dalton Trans., 2000, 3065; (h) M. J. Plater, M. R. St. J. Foreman,T. Gelbrich and M. B. Hursthouse, J. Chem. Soc., Dalton Trans.,2000, 1995.

22 For examples of self-catenation, see: L. Carlucci, G. Ciani,D. M. Proserpio and S. Rizzato, J. Chem. Soc., Dalton Trans.,2000, 3821; M. A. Withersby, A. J. Blake, N. R. Champness,P. A. Cooke, P. Hubberstey and M. Schroder, J. Am. Chem. Soc.,2000, 122, 4044; B. F. Abrahams, S. R. Batten, M. J. Grannas,H. Hamit, B. F. Hoskins and R. Robson, Angew. Chem., Int. Ed.,1999, 38, 1475.

23 Ths network can be described with a new topology(4?6?4?6?6?1012), see net # 53 in M. M. J. Treacy, K. H. Randall,S. Rao, J. A. Perry and D. J. Chadi, Z. Kristallogr., 1997, 212, 768and refs. cited therein.

24 For ideal situations, with torsion angles close to 60u, N-to-N is7.7 A; for deviations up to ¡10u the distances vary up to ¡1 A.

25 A. Altomare, M. C. Burla, M. Camalli, G. Cascarano,C. Giacovazzo, A. Guagliardi, A. G. Moliterni, G. Polidori andR. Spagna, J. Appl. Crystallogr., 1999, 32, 115.

26 G. M. Sheldrick, SHELX-97, University of Gottingen, Germany,1997.

27 L. J. Farrugia, J. Appl. Crystallogr., 1999, 32, 837.28 E. Keller, SCHAKAL99, University of Freiburg, Germany, 1999.

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