Raman Spectra of MoF6, TcF6, ReF6, UF6, SF6, SeF6, and TeF6 in the Vapor State

Abstract

Raman spectra of MoF₆, TcF₆, ReF₆, UF₆, SF₆, SeF₆, and TeF₆ have been observed for the gaseous state using laser excitation. Some assignments of fundamental frequencies have had to be revised from previously accepted values. The overtone ${\text{2ν}}_6$ was observed for all these gaseous hexafluorides and several other overtones were observed for some of the molecules. Considerable broadening of the $e_g$ and $f_{\text{2g}}$ fundamentals was observed for TcF₆ and for ReF₆. This broadening is attributed to dynamic Jahn–Teller coupling. The best currently available measured values of fundamental frequencies for all 15 hexafluoride molecules of known $O_h$ symmetry are tabulated.