An Experimental and Theoretical Investigation of the Skeletal Frequencies of the Paraffin Hydrocarbons and the Far Infra-Red Spectrum of Carbon Tetrachloride

The far infra-red spectra of the paraffin hydrocarbons and of carbon tetrachloride have been investigated. The following bands were located: propane at 370.6 cm−1, n-butane at 215 cm−1, and carbon tetrachloride at 315 cm−1, the latter showing isotope structure. The contours of the following near infra-red bands for n-butane were surveyed, and some fine structure was revealed: 1342.9 cm−1, 1295.6 cm−1, 1135.6 cm−1, 956.5 cm−1, and 740.0 cm−1. The assignment of the skeletal frequencies of vibration is made, and a theoretical analysis of the skeletal normal frequencies, assuming a valence potential for the molecules propane through pentane, is given.