Cobalt (III) chelates of tetradentate dioxime schiff bases

Abstract

The tetradentate dioxime schiff bases, 3,8-dimethyl-4,7-diazadeca-3,7-diene-2,9-dione dioxime (H₂Me₂en) and the corresponding phenyl analogue (H₂PhMeen), form a series of octahedral cobalt (III) complexes of the type [Co(HL)X₂] (H₂L = H₂Me₂en, H₂PhMeen; X = Cl, Br, I, CNS, CNSe). The ligands act as monoprotonated uninegative N₄ donors. The complexes react with BF₃·Et₂O forming the macrocyclic derivative with the O - BF₂- O bridge. The complexes have been characterised on the basis of elemental analyses, conductance, magnetic susceptibility, electronic, IR, NMR (^lH and ¹³C), ESCA spectral and thermal studies. The mass spectra of the complexes do not show any molecular ion peak but give the peaks due to the ligands only.