Reactions and energy distribution in dissociative electron capture processes in sulfuryl halides

Abstract The sulfuryl halides, SO 2 F 2 , SO 2 Cl 2 , and SO 2 ClF form several ions by dissociative electron capture. The ionization efficiency curves are determined for each process. Where the ion intensity was great enough, the kinetic energy of the ion was measured over the greater part of the electron energy of the resonance. In most instances the kinetic energy of the ion increased linearly with electron energy over the range of the resonance. Extrapolation to zero kinetic energy release give the electron energy corresponding to the heat of the dissociation reaction. The kinetic energy released in the formation of F 2 − and Cl 2 − was only slightly greater than that predicted by the quasi-equilibrium theory, as would be expected from the fact that the molecule had to change its configuration during dissociation. Essentially all the excess energy was released in translation when SO 2 F − was formed. The ions F − from SO 2 F 2 and Cl − from SO 2 Cl 2 are formed in two separate resonances, and the kinetic energy lines extrapolate to thermal appearance potentials (Δ H r ) corresponding to the formation of SO 2 and the halogen atom. The Δ H r values for these reactions as well as that for Cl 2 − at their higher energy resonances appear to correspond to an electronic transition for SO 2 of 2.5 eV.