Rotational Isomerism and the Vibrational Spectrum of 1,2-Dibromoethane

Abstract

An assignment of the vibrational frequencies of CH₂BrCH₂Br and CD₂BrCD₂Br has been made. The Raman spectra of these compounds have been redetermined using the new ``Toronto''‐type mercury arcs. It was possible, in the case of CH₂BrCH₂Br, to obtain a number of combination and overtone bands which were of assistance in the assignment. The liquid phase infra‐red spectra of both compounds have been redetermined with greater resolution and spectral range than had been previously reported. The solid infra‐red spectra of the same compounds were also determined in order to separate bands due to the trans isomer from those due to the skew isomer. Evidence for the C₂ symmetry of the high energy form has been given.