Dissociative electron attachment to S2F10, S2OF10, and S2O2F10

Abstract

The absolute cross sections for dissociative electron attachment to the molecules S2F10, S2OF10, and S2O2F10 were measured in an electron transmission experiment. The corresponding negative-ion fragments were identified in a separate mass spectrometric measurement. For S2F10, the attachment of thermal electrons (energy less than 0.1 eV) appears to result primarily in the formation of F− and SF5− with possibly a small fraction of SF4− and SF6−. The ions F− and SF5− are also produced from two attachment resonances at electron energies of about 4.5 and 9.5 eV. Both S2OF10 and S2O2F10 have unusually large dissociative attachment cross sections (on the order of 10−12 cm2) at energies near 0.1 eV. Electron attachment to S2OF10 yields primarily SOF5−, while S2O2F10 yields both SF5− and SOF5− with possible minor fractions of F− and SOF3−. Self-consistent-field calculations have been carried out on the neutral molecules and the corresponding anions to aid in the description of the observed dissociative attachment.