Vacuum ultraviolet photolysis of sulfur hexafluoride and its derivatives in argon matrices. The infrared spectrum of the SF5 radical

Abstract

Vacuum ultraviolet photolysis at 1048, 1067 Å of sulfur hexafluoride and its derivatives, SF5X (where X=Cl, Br, and SF5) in dilute argon matrices at 8 K produced two new infrared absorptions at 811.6 and 552.1 cm−1 which were also observed in the argon matrix reactions of fluorine atoms with SF4 molecules. Both features were assigned to the SF5 radical, a new species of C4v symmetry. A weaker absorption at 682.4 cm−1 was tentatively assigned to the SF3 radical, while, in the sulfur–fluorine experiments, secondary reactions produced the known SF−5 anion. The photolytic production of significant yields of SF4 and XF indicated the presence of a simultaneous molecular photoelimination process which, in the case of SF5Br, afforded the direct observation of the BrF fundamental at 650.5 cm−1.