Spectral Observations on Molecular XeF6: Raman Scattering and Infrared, Visible and Ultraviolet Absorption in the Vapor and in Matrix Isolation

Raman spectra and visible and ultraviolet absorption spectra of XeF6 vapor have been studied as functions of temperature. The changes that occur in the observed spectra are interpreted as due to relative population changes of the three electronic isomers postulated in the preceding paper. Evidence is presented that, even at temperatures as high as 100°C, it may take tens of minutes to reach equilibrium among the isomers. Infrared spectra of both XeF6 vapor at 25°C and of XeF6 molecules isolated in a low temperature argon matrix have been studied for a variety of previous thermal treatments of the XeF6 samples. In the spectra of the matrix, large differences in the relative intensities of absorption bands were found, depending on the thermal history of the XeF6 used in the deposition. All the spectra observed are interpreted in terms of the three electronic isomers, and the assignments appear quite plausible.