Electronic structure of NS compounds. A CNDO study of transition metal thionitrosyl complexes Ni(S2N2H)2 and Pd(S2N2H)2

Conformational preferences, valence molecular orbitals and electronic charge distribution in thionitrosyl complexes Ni(S2N2H)2 and Pd(S2N2H)2 have been studied by means of CNDO calculations. Both complexes are predicted to exist in the cis conformation, in agreemetn with the experimental data. Valence molecular orbital energies and compositions show that covalent interactions between transition metal and ligand are important for the metal-ligand bonding. The population analysis gives evidence of inequivalent nitrogen and sulfur atoms and of rather polar SN bonds in the planar ring. The charge distribution is tentatively correlated with the available experimental XPS binding energies. © 1981.