Endoergic ion–molecule‐collision processes of negative ions. II. Collisions of I<sup>−</sup> on H<sub>2</sub>S, CS<sub>2</sub>, and COS
作者:Kamel M. A. Refaey
DOI:10.1063/1.433299
日期:1976.9
Investigations of the cross sections for the formation of various secondary ions by endoergic collisions of I− on H2S, CS2, and COS have been made with I− ions having laboratory kinetic energies ≃0–100 eV. H2S gives the secondary ions HS−, S−, IS−, H−, and possibly IHS−. Only the secondary ions S− and IS− are observed in the case of CS2. Collision of I− on COS gives the secondary ions S−, ICO−, and O−. Because of the fact that peaks due to secondary ions are broader than normal peaks, the ions HS− and S− appear as one peak. Similarly, the ions IS− and IHS− appear as one peak. Experimental thresholds are used to deduce the heats of formation as well as the electron affinities of various species. The electron affinities obtained are: E.A.(HS) =2.2 eV, E.A.(IS) ≃2.7±0.3 eV, E.A.(IHS) ≃1.1 eV, and E.A.(ICO) ≃3.15 eV. In addition, ΔHf(ICS) has been determined as 56.6 kcal mole−1.