Spectroscopic Studies of Rotational Isomerism. V. The Infra-Red Absorption Spectra of Six Solid Hydrocarbons in the Region 1600–650 cm−1

The infra-red absorption spectra of six hydrocarbons have been measured at low temperatures. As with the Raman spectra, a considerable degree of simplification occurs on freezing, due to the existence of only one rotational isomer in the solid state. It has not proved possible to obtain accurate values of the energy differences between the isomers from this data. The possible ways of obtaining energy difference from spectroscopic data are discussed.