Raman Spectra and Calculations of the Normal Vibrations of some Organotin Compounds

Abstract

Low frequency Raman spectra of a series of tin compounds; tetramethyl-tin Me₄Sn, hexamethyldistannane Me₆Sn₂, bis (trimethylstannyl) dimethyl-tin (Me₃Sn)₂-SnMe₂, tris (trimethylstannyl) organotin (Me₃Sn)₃ SnR (R = Me, Et, Bu, i–Bu, n-pentyl and phenyl) and tetrakis (trimethylstannyl) tin (Me₃Sn)₄Sn, were recorded and assigned in the region 0–600 cm^–1. The normal vibrations of these compounds have been calculated and discussed in relation to the observed spectra. It was evident from the data that on going from Me₈Sn₃ → Me₁₀Sn₄ → Me₁₂Sn₅, the change in the vibration frequencies was very small and no shifts are observed for the C–Sn–Sn–stretching vibrations. On the other hand the symmetric and asymmetric stretching vibrations of Sn–Sn display a systematic decrease in the frequencies, which is in harmony with the calculated data. The decrease in vibration frequencies correlate well with published data of ¹J(Sn–Sn) coupling constant.