Vibrational Spectra of Fluorinated Aromatics. XIII. Benzotrifluoride

Abstract

The infrared absorption spectrum of gaseous benzotrifluoride has been obtained with a 1-m cell and a Perkin-Elmer double-pass spectrometer equipped with NaCl and CsBr prisms. The Raman spectrum of liquid C6H5CF3 has been photographed with a 3-prism glass spectrograph of reciprocal linear dispersion 15 A/mm at 4358 A, and depolarization ratios have been measured for most of the Raman bands. Under the assumptions that the molecule has approximately the symmetry C2v and that phenyl and CF3 vibrations are weakly coupled, all but 3 of the vibrational fundamentals have been assigned and classified as follows: Species a1: 336, 770, 1004, 1028, 1072, 1180, 1457, 1614, 2995, 3022, and 3096 cm—1; Species b1: 199, 618, 902, 1127, 1237, 1362, 1457, 1614, 3022, and 3096 cm—1; Species b2: 139, 485, 695, 770, (800), and 923 cm—1; Species a2: 235, 844, and (ca 950) cm—1; CF3 vibrations: (ca 150), 321, 398, 596 (2 funds.), 657, 1152 (2 funds.), and 1328 cm—1. The spectra have been interpreted in detail.