Organothiometallic compounds. Part I. Infrared and Raman spectra of some di(alkylthio)mercury(II) compounds

Abstract

I.r. and Raman spectra in the range 800–100 cm^–1 of a series of di(alkylthio)mercury(II) compounds Hg(SR)₂(I; R = Me, Et, Prⁿ, Prⁱ, Buⁿ, Buⁱ, or Bu^t) have been recorded and discussed. The main fundamentals have been identified in the following ranges: ν(C–S), 575–725, ν(S–Hg–S), 200–338 in the solid and 209–371 cm^–1 in solution. The spectral features agree with a linear S–Hg–S structure and with the characteristic two-co-ordination of mercury. Spectra of the solid (I; R = Bu^t) differ from those of the other compounds and are interpreted on the basis of a polymeric centrosymmetric structure. The spectral pattern of some of the compounds (I) suggest the existence in solution of more than one rotational isomer. The frequency ν(S–Hg–S) in the solid, related to the strength of the mercury–sulphur bond, decreases with increasing electron-releasing ability of the alkylthio-groups. However, a strictly linear correlation between ν(S–Hg–S) and the basicity of the alkyl radicals does not exist.