Molecular electron affinities from collisional ionization of cesium. II. SF6 and TeF6

Abstract

The relative cross sections for the production of mass selected negative ions resulting from collisions of Cs with SF₆ and TeF₆ have been studied as a function of the incident cesium atom energy from 0 to 40 eV. Electron affinities (E.A.) for SF₆ and TeF₆ are derived from accurate measurements of the threshold for ion‐pair production with the results $\mathrm{E.A.}\mathrm{\hspace{0.17em}(}{\mathrm{SF}}_6{\text{)=0.54}}_{\text{−0.17}}^{\text{+0.1}}\hspace{0.17em}\mathrm{eV}$ and $\mathrm{E.A.}\mathrm{\hspace{0.17em}(}{\mathrm{TeF}}_6{\text{)=3.34}}_{\text{−0.17}}^{\text{+0.1}}\hspace{0.17em}\mathrm{eV}$ . Dissociative ionization studies resulted in E.A.(SF₅) ≥ 2.8 ± 0.2 eV and $\mathrm{D(}{\mathrm{SF}}_6^{-}-\mathrm{F}\text{)=1.05± 0.1\hspace{0.17em}}\mathrm{eV}$ .