Hydrogen-bonded supramolecular architectures in (N-(methylpyridin-2-yl)-amidino-O-alkylurea)copper(ii) halides

Suksangpanya, U., Blake, A. J., Cade, E. L., Hubberstey, P., Parker, D. J. and Wilson, C. (2004) Hydrogen-bonded supramolecular architectures in (N-(methylpyridin-2-yl)-amidino-O-alkylurea)copper(ii) halides. CrystEngComm, 2004(28), pp. 159-167. (doi: 10.1039/B405875E)

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Abstract

Methanolysis and ethanolysis of N-(methylpyridin-2-yl)-2-cyanoguanidine in the presence of copper(II) chloride or bromide yielded four products of identical stoichiometry, Cu(L3i)X2 [L3i = L3m {N-(methylpyridin-2-yl)-amidino-O-methylurea} or L3e {N-(methylpyridin-2-yl)-amidino-O-ethylurea}; X = Cl or Br]. Recrystallisation gave the four L3i-containing copper(II) halides, [Cu(L3m)Cl2], 1, [Cu(L3e)Cl2], 2, [Cu(L3e)(OH2)Cl]Cl, 3 and [Cu(L3m)Br2]·MeOH, 4, structural analysis of which showed their crystal engineering to depend on just three of the four N–H donors of the co-ordinated tridentate ligand. In all four compounds, two of the N–H donors are used, in conjunction with halide acceptors, to generate the same R12(6) hydrogen-bonded supramolecular synthon. Whereas in 1, 2 and 3 the synthons form part of hydrogen-bonding assemblies generating centrosymmetric dimers, in 4 they are used to generate a hydrogen-bonded 1-D chain. The dimers in 1 and 2 are identical but for the pendant O-alkyl group, the two centrosymmetrically related [Cu(L3i)X2] monomers being linked by pairs of R12(6) hydrogen-bonding assemblies. The dimer in 3 is simply an extended version of those in 1 and 2, in which the halide anion, instead of being co-ordinated to the copper centre, is hydrogen-bonded to a co-ordinated water molecule of the [Cu(L3e)(OH2)Cl]+ cationic monomer. The extended architectures of the structures depend on hydrogen-bonding interactions involving the third N–H donor, which lead to 1-D chains (in 2), 2-D sheets (in 1 and 4) or, with the assistance of a water hydrogen atom, 3-D networks (in 3). In the absence of further hydrogen-bonding, weak Cu⋯N co-ordinate and π–π stacking interactions form the basis of the forces linking the chains and sheets into 3-D networks.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Wilson, Dr Claire
Authors: Suksangpanya, U., Blake, A. J., Cade, E. L., Hubberstey, P., Parker, D. J., and Wilson, C.
College/School:College of Science and Engineering > School of Chemistry
Journal Name:CrystEngComm
Publisher:Royal Society of Chemistry
ISSN:1466-8033
ISSN (Online):1466-8033
Published Online:18 May 2004

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