Resonance-Raman spectra of copper(II) and nickel(II) diethyldithiocarbamates

Abstract

Copper(II) and nickel(II) diethyldithiocarbamates display a resonance-Raman spectrum when excited with laser lines at wavelengths approaching that of the first allowed charge-transfer (c.t.) transition. Both spectra show the preferential intensity enhancement of four bands in the M–S stretching and SCS, SCN, MSC, and SMS bending region at 157–367 cm^–1. Except for one deformation mode, all the bands are polarized. Assignments of these bands have been made by comparison with normal-co-ordinate analysis data for dithiocarbamato-complexes. The experimental intensity dependence on Albrecht frequency factors suggests a Raman activity derived from mixing between one c.t. and one ligand transition. The two electronic transitions involved have been assigned by taking into account depolarization ratios and using polarized absorption data and molecular-orbital calculations from the literature.