Article
-7, intermolecular carbonyl carbonyl interaction is re-
Crystal Growth & Design, Vol. 11, No. 3, 2011 841
2
þ
complexes containing a common dinuclear [Ag (L) ] me-
2 2
5
3
3 3
vealed as a common dominant noncovalent interaction that
plays an important role. As structural analysis indicated that
such weak noncovalent interaction rarely exists alone in
small-molecule crystal structures based on CSD database
tallacyclic skeleton. Intermolecular multipolar carbonyl
3
3 3
carbonyl interaction is a common dominant interaction in
complexes 1-3 and 5-7, which combine with argentophilic
Ag(I) Ag(I), heteroaromatic π π, hydrogen-bonding,
3
3 3
3 3 3
2
5
research, additional intermolecular interactions also coex-
ist in complexes 1-3 and 5-7. In these complexes, the
Ag3 3 3
OdC, O(trifluoroacetate) CdO, as well as uncon-
ventional CdO π and anion-π(pyridyl) interactions, to
3 3 3
3
3 3
carbonyl carbonyl interaction combines with Ag Ag,
3
assemble the helical (1, 2) and metallacyclic moieties (3, 5-
7) into higher-dimensional metal-organic frameworks. Three
3 3
3 3 3
π
π, hydrogen-bonding, Ag OdC, O(anion) CdO
3
3 3
3 3 3 3 3 3
interactions, as well as unconventional CdO π and anion-
principal types of carbonyl carbonyl interaction, namely,
3
3 3
3 3 3
π(pyridyl) interactions, to assemble different coordination
motifs (infinite chains in 1-2, metallacycles in 3 and 5-7)
into higher-dimensional supramolecular frameworks. The
antiparallel, sheared parallel, and perpendicular motifs sur-
veyed by Allen are substantiated and shown to play an
important role in supramolecular conglomeration of these
silver complexes. Unusual supramolecular associations such
carbonyl carbonyl interactions in 1-3 and 5-7 exhibit
3
3 3
flexible contact configurations. The typical antiparallel mo-
tif occurs in 7 (A1-A4 = 90ꢀ, τ = 0ꢀ), the perpendicular
motif is found in 6 (A1 close to 180ꢀ, τ = 72.1ꢀ), while the
antiparallel and sheared parallel motifs in 1-3 and 5 have
similar geometrical features (see Table 2). In the present
context, we designate a carbonyl carbonyl contact with a τ
as “ [CdO CdO]n ” (in 1-2, 6) and “ [CdO
3
3 3 3 3 3 3 3 3 3 3 3
3 3 3
CdO π]n ” (in 3) and “CdO CdO CdO” (in 7)
3 3 3 3 3 3 3 3 3 3 3
3
are the novel structural features observed in this work. These
dipolar dipolar interactions exhibit variable geometrical
3
3 3
arrangements in response to the presence of different coexist-
ing counteranions, and their cooperative effect with other
noncovalent interactions contrive to consolidate molecular
packing in the crystal structures of 1-3 and 5-7.
3
3 3
>
60ꢀ as sheared parallel and that with a τ < 60ꢀ as
antiparallel motif. Furthermore, the antiparallel (in 1-3, 7)
and sheared parallel (in 1-2, 5, and 7) motifs occur more
frequently than the perpendicular motif (in 6) in the present
series of silver(I) complexes, and the values of the A1 angle
are commonly larger than those of other A2-A4 angles in
each case. This result may be reasonably ascribed to the fact
that when a pair of carbonyl groups comes into close contact,
steric repulsion between substituents would lead to a larger
A1 angle and preferred adoption of the antiparallel or
sheared motifs rather than the perpendicular motif. This
phenomena was observed in crystals of small organic mole-
Acknowledgment. This work is supported by the Hong
Kong Research Grants Council (GRF Ref. No. CUHK
02206) and the Wei Lun Foundation.
4
Supporting Information Available: Crystallographic data of 1-7
in CIF format. This material is available free of charge via the
Internet at http://pubs.acs.org. CCDC-789268-789274 contain the
supplementary crystal data for 1-7, respectively. These data can be
obtained free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif.
3
cules by Allen, and it also agrees well with a recent survey on
the relative orientations of neighboring intermolecular car-
4
References
bonyls in organic crystals by Lee.
Regarding the contact strength, in this study the measured
(
1) (a) Jeffrey, G. A.; Saenger, W. Hydrogen Bonding in Biological
Systems; Springer-Verlag: Berlin, 1999; (b) Taylor, R.; Mullaley, A.;
M €u llier, G. W. Pestic. Sci. 1990, 29, 197–213.
˚
values of D1 lie within a narrow 2.975-3.432 A range, being
˚
comparable to the 2.92-3.32 A range from ab initio
calculations, but slightly longer than 2.796 A in the orga-
3
a
(2) Gavezzotti, A. J. Phys. Chem. 1990, 94, 4319–4325.
˚
(
3) (a) Allen, F. H.; Baalham, C. A.; Lommerse, J. P. M.; Raithby,
P. R. Acta Crystallogr. B 1998, 54, 320–329. (b) Deane, C. M.; Allen,
F. H.; Taylor, R.; Blundell, T. L. Protein Eng. 1999, 12, 1025–1028.
(c) Wood, P. A.; Borwick, S. J.; Watkin, D. J.; Motherwell, W. D. S.;
Allen, F. H. Acta Crystallogr. B 2008, 64, 393–396. (d) Sparkes, H. A.;
Raithby, P. R.; Clot, E.; Shield, G. P.; Chisholm, J. A.; Allen, F. H.
CrystEngComm 2006, 8, 563–570.
4) Lee, S.; Mallik, A. B.; Fredrickson, D. C. Cryst. Growth Des. 2004,
4, 279–290.
5) (a) MacCallum, P. H.; Poet, R.; Milner-White, E. J. J. Mol. Biol.
5
5
nometallic complex (η -C H )W(CO) (η -N-maleimidato)
5
5
3
owing to the presence of the coordinated carbonyl group
9
ion-polarization) in the latter. Such intermolecular carbo-
(
nyl carbonyl interaction is a type of weak noncovalent
3
3 3
interaction, which is competitive with hydrogen bond as
The diversity of the presence and geome-
3-5
already noted.
tries of this type of intermolecular contact in complexes 1-7
(
(
well substantiates this conclusion. No carbonyl carbonyl
3
3 3
1
2
995, 248, 374–384. (b) Lario, P. I.; Vrielink, A. J. Am. Chem. Soc.
003, 125, 12787–12794. (c) Pal, T. K.; Sankararamakrishnan, R.
J. Phys. Chem. B 2010, 114, 1038–1049 and references therein.
interaction is found in 4, while the contacts of 5-7 exhibit
distinct configurations (sheared parallel motif in 5, perpen-
dicular motif in 6 and typical antiparallel motif in (7)) despite
the fact that isostructural complexes 4-7 contain a similar
(6) (a) Berman, H. M.; Westbrook, J.; Feng, Z.; Gilliland, G.; Bhat,
T. N.; Weissig, H.; Shindyalov, I. N.; Bourne, P. E. Nucleic Acids
Res. 2000, 28, 235–242. (b) Allen, F. H. Acta Crystallogr. B 2002, 58,
80–388.
7) (a) B u€ rgi, H. B.; Dunitz, J. D.; Shefter, E. J. Am. Chem. Soc. 1973,
5, 5065–5067. (b) B €u rgi, H. B.; Dunitz, J. D. Acc. Chem. Res. 1983,
16, 153–161. (c) Schweizer, W. B.; Procter, G.; Kaftory, M.; Dunitz,
J. D. Helv. Chim. Acta 1978, 61, 2783–2880.
8) Paulini, R.; M u€ ller, K.; Diederich, F. Angew. Chem., Int. Ed. 2005,
2
þ
dinuclear [Ag (L) ] metallacyclic skeleton. The present
2
2
3
investigation shows that the nature of particular anions in
isostructural complexes 4-7 has a subtle influence on the
precise microarchitecture of these supramolecular aggrega-
tions, including the configurations of the weak carbonyl
(
9
3
3 3
(
(
carbonyl interaction.
44, 1788–1805 and references therein .
9) Palusiak, M.; Rudolf, B.; Zakrzewski, J.; Pfitzner, A.; Zabel, M.;
Grabowski, S. J. Organomet. Chem. 2006, 691, 3232–3238.
Conclusions
(
(
10) SMART 5.0 and SAINT 4.0 for Windows NT, Area Detector
Control and Integration Software; Bruker Analytical X-Ray Systems
Inc.: Madison, WI, 1998.
11) Sheldrick, G. M. SADABS: Program for Empirical Absorption
Correction of Area Detector Data; University of G €o ttingen:
G €o ttingen, Germany, 1996.
In the present series of silver(I) complexes of 2,6-
pyridinediylbis(4-pyridinyl)methanone ligand (L), complexes
and 2 are isomorphous helical polymers, and 3 is a metalla-
1
cycle featuring a trisilver(I) core, while 4-7 are isostructural