Communication: Revised electron affinity of SF6 from kinetic data

Abstract

Previously determined experimental data for thermal attachment of electrons to SF6 and thermal detachment from SF6- over the range 590-670 K are reevaluated by a third-law analysis. Recent high precision calculations of SF6- harmonic frequences and anharmonicities (for several of the modes) lead to considerable changes in modeled vibrational partition functions which then have to be accommodated for by a smaller value of the derived adiabatic electron affinity EA of SF6. The previously estimated value of EA = 1.20 (+/- 0.05) eV in this way is reduced to a value of EA = 1.03 (+/- 0.05) eV. In addition, the bond dissociation energy E-0,E-dis for SF6 -> SF5 + F is reduced to E-0,E-dis = 1.44 (+/- 0.05) eV. Finally, the consequences for modeled specific rate constants k(det)(E,J) of electron detachment from SF6- are discussed. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3698170]