An Electron Spin Resonance Study of Some Reactions of Pentafluorosulfuranyl (SF5)

A kinetic electron spin resonance study of the self-reaction of SF 5 and a spectroscopic and kinetic e.s.r. study of the reaction of SF 5 with 1,1-di-t-butylethylene are reported. This radical undergoes self-reaction by a second-order process and the rate constants are given by the Arrhenius equation log 2k 1 (M − 1 s −1 ) = (10.3 ± 0.5) − (1.7 ± 0.5)/θ where θ = 2.303RT kcal mol −1 . It adds to 1,1-di-t-butylethylene to give (t-Bu) 2 CCH 2 SF 5 which decomposes by a first-order process with rate constants that obey the expression log k 2 (s −1 ) = (13 ± 0.4) − (10 ± 0.2)/θ. Both these rate constants are pertinent to kinetic studies of the photoinduced addition of SF 5 C1 to olefins.