Ligational Behaviour of bis(Biacetylmonoxime)carbo-hydrazone (H₃BMC) Towards Transition Metal Ions

Abstract

The synthesis and characterization of Fe(III), Co(III), Co(II), Ni (II), Cu (II), Zn (II), Cd (II) and UOć complexes of bis(biacetylmonoxime) carbohydrazone (H₃BMC) are reported. Elemental analyses, molar conductance, magnetic moment and spectral (i. r., visible and n. m. r) measurements have been used to characterize the complexes. I. r. spectral data show that the ligand behaves in a tetradentate and/or pentadentate manner. The behaviour of the ligand towards any metal ion depends on the type of anion and the preparative conditions. An octahedral structure is proposed for the Fe (III), Co (III), Co (II) and the Ni (II) complexes which were prepared from the chloride, bromide, nitrate or sulphate salts. A square-planar structure is proposed for Cu (II) and the Ni (II) complexes derived from the acetate and thiocyanate salts on the basis of magnetic and spectral measurements. H₃BMC acts as an oxidizing agent towards Co (II) chloride forming a diamagnetic Co (III) complex. All the complexes are non-electrolytes except [Ni (H₃BMC)](SCN)₂ which exhibits an electrolytic nature.