Cadmium(II) and cobalt(II) complexes generated from benzimidazole-5-carboxylate: Self-assembly by hydrogen bonding and image interactions

Self-assembly of L− (HL=benzimidazole-5-carboxylic acid) with Cd(II) and Co(II), respectively, by layer-separating diffusion method at ambient temperature gives rise to two new supramolecular architectures [(CdL2·H2O)·2CH3OH]n (1) and {[CoL2(H2O)2]·2H2O}n (2), both of which are stabilized by the hydrogen bonding interactions and the intermolecular image interactions. 1 crystallizes in the triclinic system, space group image, with cell parameters image, image, image, image, image, image, image, image, image, image, image. 2 crystallizes in the monoclinic system, space group C2/c, with cell parameters image, image, image, image, image, image, image, image, wR2 image. Complex 1 displays a remarkable three-dimensional (3-D) structure with unusual channels generated from the interlayer voids. Complex 2 exhibits the 3-D structure consisting of 1-D zigzag chains. The thermal and fluorescence properties associated with their crystal structures have been measured, and complex 1 displays intense blue emission in the solid state.