Spectroscopic study of internal rotation in chloroethanes

Abstract

Torsional frequencies have been assigned in the far infra-red and Raman spectra of C₂H₅Cl, CH₃˙ CHCl₂, CH₂Cl ˙ CH₂Cl, CHCl₂CH₂Cl, CH₂Cl ˙ CCl₃, CHCl₂˙ CHCl₂ and CHCl₂˙ CCl₃. Barrier heights have been calculated for the symmetric top molecules; V₃ ranges from 3.3 to 14.2 kcal mole^–1. The problem of estimating barriers in asymmetric top molecules is more difficult. Nevertheless, for these molecules, barrier heights ranging from 5.1 to 12.0 kcal mole^–1 have been calculated, which are comparable in magnitude to those obtained for the symmetric top molecules.