Influence of environment on torsional vibrations. Part 1.—n-Propyl halides

Abstract

The far infra-red spectra of n-propyl chloride, bromide and iodide have been examined to 60 cm^–1 in the vapour, liquid and crystalline phases; these permit the vibrational assignment to be completed. The influence of the phase on the skeletal torsion frequency is discussed in the light of theories of the origin of torsional barriers.