Synthesis and structural characterization of cobalt(II) complexes based on 4-(1 H -imidazol-1-yl)aniline and arene-carboxylate ligands

Abstract The complexes Co(ima) 2 (nba) 2 (H 2 O) 2 ( 1 ) and Co(Hima) 2 (bta)(H 2 O) 2 ( 2 ) have been synthesized and characterized by single-crystal X-ray diffraction and IR spectroscopy (ima = 4-(1 H -imidazol-1-yl)aniline, Hnba = 4-nitrobenzoic acid, H 4 bta = benzene-1,2,4,5-tetracarboxylic acid). Complex 1 has a mononuclear structure while complex 2 exhibits a multinuclear chain structure. These components are further extended to afford kgd sheets for 1 and a three-dimensional fsc network for 2 , with the aid of abundant hydrogen-bonding interactions. The structural diversity indicates that the carboxylate ligands induce a change in the protonation state of the ima ligand in the two complexes, thereby playing a critical role in the increase of the dimensionality of the supramolecular substructures from 2D in 1 to 3D in 2 .