Electrochemical synthesis and characterization of cobalt(II), cobalt(III), and nickel(II) complexes with pyrimidine-2-thionato ligands

The electrochemical oxidation of anodic metal (cobalt and nickel) in acetonitrile solutions of the appropriate pyrimidine-2-thione derivatives (RpymSH, where R = 4-CF3, 4,6-CF3Me, 4,6-MePh, 4,6-CF3Ph, 4,6-Ph-2) afforded complexes of composition [M(RpymS)(2)], M = Co, Ni or [Co(RpymS)(3)]. When 2,2'-bipyridine (bipy) or 1,10-phenanthroline (phen) was added to the electrolytic cell, adducts of cobalt(II) and nickel(II) compounds with these coligands were obtained: [M(RpymS)(2)bipy] and [M(RpymS)(2)phen]. All of the compounds were characterized by microanalysis, electronic, vibrational spectroscopy and FAB mass spectrometry, and, in the cases of the compounds [Co(RpymS)(3)], by H-1 and C-13, NMR spectroscopy. The compound [Co(4-CF(3)pymS)(3)] was also characterized by X-ray diffraction. The crystal structure consists of monomeric molecules in which the central CsS3N3 unit has a slightly distorted octahedral coordination with the ligands adopting a meridional disposition.