Anionic Reactions Degrading SF₆ Using Metals: Insights From the Gas Phase

Alkali metals have been used to degrade SF₆ in liquid ammonia. The products include metal fluorides. In this study, we reacted K^- and Ag^- with SF₆ in a triple quadrupole mass spectrometer. The atomic metal anions were formed by in-source collision-induced dissociation (CID) of their respective oxalate salts as previously described by our group. The only two reaction products observed were SF₆ ^- and SF₅ ^-. At low collision energy, the latter was deduced to be formed via an abstraction by the metal of F from SF₆ ^- formed by electron transfer in the encounter complex between the metal anion and neutral SF₆. As the collision energy was increased, there was evidence of a CID contribution to SF₅ ^- directly from SF₆ ^-.