SYNTHESES AND ELECTROCHEMISTRY OF SOME TRANSITION-METAL COMPLEXES WITH 2-MERCAPTOPYRIDINE N-OXIDE AND CRYSTAL-STRUCTURE OF BIS(2-MERCAPTOPYRIDINE N-OXIDE)NICKEL(II)

The complexes M(mpo)n (M = Mn, Ni, n = 2; M = Fe, Co, n = 3) (Hmpo = 2-mercaptopyridine N-oxide) were prepared by reacting the appropriate metal chloride with either Nampo or dtpo [2,2-dithiobis(pyridine N-oxide)] in the presence of sodium methoxide. The structure of the complex Ni(mpo)2 was determined by X-ray diffraction. The nickel atom is in a square planar environment of two mpo- ligands in the cis configuration. The four complexes were investigated by physicochemical methods especially by H-1 NMR spectroscopy and cyclic voltammetry.