Ligational behaviour of pyridine-2,3-dicarboxylic acid with nickel(II) in presence of imidazoles

The mixed ligand complexes of stoichiometry NiABH, NiAB and NiAB2 have been detected in the Ni-pyridine-2,3-dicarboxylic acid(A)-imidazole, -benzimidazole, -histamine and -L-hisUdinc (B) systems. The results indicate that in NiABh species the extra proton resides with ligand B. In NiAB and NiAB2 complexes, pyd and hist are tridentate, hist is bidentate and him and him are monodentate.