CHEMICAL AND ELECTROCHEMICAL SYNTHESIS OF TRANSITION METAL COMPLEXES OF BUTYLMALONIC ACID DIHYDRAZIDE AND ITS SALICYLOYL HYDRAZONE

摘要

Iron, cobalt, nickel and copper complexesof butylmalonic acid dihydrazide (H_2BMD) and itssalicyloylhydrazone (H_4BMS) have been prepared byinteraction of the ligands with the metal saltsolutions or by direct electrochemical oxidation of themetal in acetone solution of the ligand. Higher yields(85-90%) were obtained by the electrochemical method.IR spectra show that H_2BMD and H_4BMS behave as neutralor binegative ligands binding in a bidentate,tridentate and/or tetradentate manner, depending onthe preparative conditions. Different (octahedral,tetrahedral and square-planar) geometries aresuggested for the isolated complexes based on magneticand electronic spectral studies. The ligand fieldparameters of the Co(II) and Ni(II) complexes werecalculated and the variation of their values with thechange of coordination sites is discussed.