Band Series in Infra-Red Absorption Spectra of Organic Compounds. I

The frequencies of a series of outstanding absorption bands characteristic of organic liquids, previously attributed by the author to vibrations between atoms of a carbon-hydrogen pair, are shown to fit the equation, νₙ·10^-12=47.37n-0.783n², where n=1, 2, ., 10. Many of the bands of secondary intensity in the spectra of compounds containing a carbon-carbon bond have their frequencies expressed by ν^'ₙ·10^-12=10.71n. where n=1, 2, .., 28. Practically all other bands observed below 7{μ} in such spectra can be accounted for by combinations of low frequency members of these two series, νc=νₘ+νₙ^'. Measurements on bands occurring between 2{μ} and 3{μ} were made from records obtained with a new registering spectrograph. A number of such spectra are shown.