1D, 2D and 3D cadmium(II) polymeric complexes with quinoline-4-carboxylato anion, quinazoline and 2,5-dimethylpyrazine

Three new cadmium(II) complexes, namely [Cd(Qux)(2)(H2O)]n (1), [Cd(Quz)(2)(N-3)(2)](n) (2) and [Cd(dmpz)(N-3)(2)](n) (3) (Qux = quinoline-4-carboxylato anion, Quz = quinazoline, dmpz = 2,5-dimethylpyrazine), have been synthesized and characterized by spectroscopic and crystallographic methods. The structure of 1 contains CdO6 slightly distorted octahedral geometry around the Cd(II) atoms, axialy coordinated to two bridging water molecules forming the 1D chain and four oxygen atoms from four different mu-O,O'-bridging caboxylato groups of (Qux) in the equatorial plane. The ID chains are further held together through hydrogen bonds between the P-aqua molecule and the meta non-coordinated nitrogen atom of the quinoline moiety. In complex 2, two quinazoline ligands are linked to the central Cd(II) ion in a trans position through the meta hetero nitrogen atom and di(EE), (mu(1,3)-N-3) groups and show a two dimensional (2D) topology. In complex 3 the central cadmium(II) atom is simultaneously coordinated to di(EE), (mu(1.3)-N-3) groups (N-Cd-N, 180.0 degrees) forming a sheet structure in the bc plane and further bridging mu-N,N'-dimethylpyrazine ligand in the a-direction (N-Cd-N, 180.0 degrees) giving rise to a 3D network structure. The IR spectra of the three complexes were measured and they confirm the X-ray structural data. (c) 2005 Elsevier Ltd. All rights reserved.