Vibrational Spectra of Fluorinated Aromatics. III. 1,4-Difluorobenzene

Abstract
The infrared absorption spectra of gaseous and liquid 1,4‐difluorobenzene have been obtained in the regions 2–22μ and 2–38μ, respectively, with the aid of LiF, NaCl, KBr, and KRS−5 prisms. The Raman spectrum of the liquid phase has been photographed with a three‐prism glass spectrograph of linear dispersion 15A/mm at 4358A. Depolarization ratios have been measured for the stronger Raman bands. A complete assignment of fundamental vibration frequencies has been made, and the spectra have been interpreted in detail. The nonplanar frequencies have been calculated with the aid of force constants determined for related molecules