The Raman spectra of gaseous and liquid cis- and trans-2-butene have been obtained with a three-prism glass spectrograph of linear dispersion 15A/mm at 4358A, together with polarization data for these compounds in the liquid state. For each compound six or seven fundamentals have been added to previous assignments, and one change has been made in the latter. The observed spectra have been interpreted in detail.
CHARLES M. RICHARDS and J. RUD NIELSEN, "Raman Spectra of Cis- and Trans-2-Butene in the Gaseous and Liquid States," J. Opt. Soc. Am. 40, 442-445 (1950)