Raman and Infrared Spectral Data for CH2Br2, CHDBr2, and CD2Br2

Abstract

Raman displacements, relative intensities, and depolarization ratios have been observed for CH₂Br₂, CD₂Br₂, and CHDBr₂ in the liquid phase, and the wavenumbers and relative intensities for the infrared bands from 400–4000 cm⁻¹ have been obtained for both the liquid and vapor phases. All but five of the 90 bands observed for the liquid phases of these methanes have been assigned to fundamentals, first overtones, and binary combinations. The assignments for the fundamentals of CH₂Br₂ are in agreement with previous assignments of Plyler, Smith, and Acquista, but the assignment for the b₁ fundamental of CD₂Br₂ at 2313 cm⁻¹ differs from that of Dowling. The assignments for CD₂Br₂ were made by comparison with those for CH₂Br₂, and those for CHDBr₂ were made with the aid of the Brodersen and Langseth complete isotopic rule. The present assignments are in better agreement with that rule than are the previous assignments.