Carbodithioato derivatives of weak nitrogenous nucleophiles. I. Electronic structure and ground state properties of Ni(II) amide N-carbodithioates

Abstract

Nickel(II) complexes of the general type [Ni(S2CN(COR′)R)2] have been synthesized by the reaction of the appropriate Ni(II) N-alkyldithiocarbamate with acetic anhydride or benzoyl chloride in the presence of triethylamine. The complexes obtained were identified and characterized by elemental analyses, conductivity measurements, and ir and electronic spectra. It was concluded that the bonding mode of the dithiocarbamato ligands to the metal ion is not altered by the acylation reaction, the chromophore remaining square-planar NiS4. Moreover, EHMO-SCCC calculations have been used in the analysis of electronic structure, and related properties of the novel compounds. From the calculated molecular orbital description of the complexes and the frontier molecular orbital approach of chemical reactivity, plausible mechanisms of their formation reactions have been deduced. Keywords: Ni(II) amide N-carbodithioates, N-alkyldithiocarbamates, dithiocarbimates, electrophilic substitution reactions, EHMO-SCCC calculations.