Raman spectra and structure of B2F4 in the gaseous and solid states

Abstract

The Raman spectra of B2F4 have been recorded from 25 to 1500 cm−1 with the sample in both the gaseous and crystalline states. An assignment of the normal vibrations of the molecule in the planar form is presented. No evidence could be found for the conversion from the D2h form in the solid to a nonplanar D2d form in the gas as had been previously reported. It appears that the rule of mutual exclusion is retained in the spectra for the vapor and liquid states and that the molecule has D2h symmetry in all physical states. The optically active translations and librations have been observed in the low frequency infrared and Raman spectra of the solid, respectively. Intermolecular force constants have been calculated.