Spectroscopic studies of organoselenium compounds—i : The structure of phenylselenium compounds

Abstract

The IR and UV spectra of diphenylselenium, diphenylselenium dichloride and triphenylselenonium chloride have been discussed. The splitting in the 750 cm -1 region for the phenyl selenium compounds is suggested to be due to one of the rings being non-equivalent with the other. The intensities of the bands in the 1100 and 1400 cm -1 regions have been used in support of the structure which is suggested to be angular for diphenylselenium and unsymmetrical tetrahedral for diphenylselenium dichloride and unsymmetrical pyramidal for the triphenylselenonium cation. The similarity of the UV spectra of II and III is suggested to be due to the electronic oscillations extending only through two phenyl groups. The non-equivalence of rings may be a result of the coulombic repulsions of the neighbouring phenyl groups or due to an intra-molecular interaction of the anion.