Synthesis, Characterization, Spectroscopic, and Thermal Studies of Imidazole Complexes of Metal Benzenesulfonates. Crystal Structure of [M(imH)(3)(H2O)(3)]center dot(BS)(2) [M=Ni(II) and Co(II)]

Abstract

Four novel transition metal benzenesulfonate (BS) complexes of imidazole (im) with a general formula [M(imH)(3)(H2O)(3)]center dot(BS)(2) [M=Mn(II) (1), Ni(II) (2), Co(II) (3)] and [Cu(BS)(imH)(3)]center dot(BS) (4) have been synthesized and characterized by physicochemical and spectroscopic methods. The complexes 2 and 3 have also been characterized by single X-ray diffraction technique. The BS anion in complexes 1-3 acts as a counter anion, while in complex 4, it acts as both ligand and counter anion. The Ni and Co complexes are isomorphous, crystallizing in the monoclinic crystal system with C2/c space group. Each metal(II) atom in 2 and 3 is octahedrally coordinated by three imidazole and three aqua ligands, adopting a mer-coordination mode with Ni(II) or Co(II) centers. In both 2 and 3, the H2C atom has bifurcated donor (O3 and O5) atoms, forming a bifurcated hydrogen bond. This hydrogen bond links the complex cation and BS anion, forming one-dimensional hydrogen-bonded supramolecular chains. The complexes exhibit different decomposition characteristics. Magnetic susceptibility measurement shows that complex 3 has orbital interactions.