Infrared and Raman spectra of fluorinated ethanes: Part XVII. CF 2ClCH 2Cl and CF 2BrCH 2Br

Abstract

The infrared absorption spectra of gaseous, liquid and solid CF 2ClCH 2Cl, and of gaseous and solid CF 2BrCH 2Br, have been obtained with a Perkin-Elmer Model 112 double-pass spectrometer equipped with CsBr, NaCl, and LiF prisms. The Raman spectra of both compounds in the liquid state have been photographed with a 3-prism glass spectrograph of reciprocal linear dispersion 15 Å/mm at 4358 Å. In the gaseous and liquid states these compounds exist as a mixture of rotational isomers. In the solid state only one isomer is present. Tentative assignments of fundamentals for each isomer have been made. For CF 2ClCH 2Cl the standard enthalpy difference between the rotational isomers was found to be Δ H° (gas) = 430 ± 100 cal/mole. For CF 2BrCH 2Br Δ H° (gas) = 1030 ± 100 cal/mole.