Collision-induced dissociation and charge transfer reactions of SF+x (x=1–5): Thermochemistry of sulfur fluoride ions and neutrals

Abstract

Guided ion beam mass spectrometry is used to measure the cross sections for collision-induced dissociation of SFx+ (x=1–5) with Xe. The energy dependences of the cross sections are analyzed to give the following 0 K bond dissociation energies (BDEs): D°(SF4+–F)=4.60±0.10 eV, D°(SF3+–F)=0.36±0.05 eV, D°(SF2+–F)=4.54±0.08 eV, D°(SF+–F)=4.17±0.10 eV, and D°(S+–F)=3.56±0.05 eV. The ionization energies, IE(SF)=10.16±0.17 eV, IE(SF3)=8.18±0.07 eV, IE(SF4)=11.69±0.06 eV, and IE(SF5)=9.60±0.05 eV, are also measured from analysis of endothermic charge–transfer reactions. From these BDEs and IEs, we derive heats of formation for the sulfur fluoride ions and neutrals that provide a self-consistent set of thermochemical data for the sulfur fluoride species. In some cases, the thermochemical values determined here are considerably different from available literature values. These differences are discussed in detail.