Dissociative electron attachment to polyatomic molecules: ion kinetic energy measurements

Abstract

Dissociative electron attachment to SO₂, NO₂, NF₃ and H₂O₂ is studied in terms of the kinetic energies of the dominant fragment ions. The O⁻ data from SO₂ show that the two major resonances at 4.6 and 7.2 eV respectively have the same dissociation limit. Similarly, the resonances at 1.8 and 3.5 eV in the O⁻ channel in NO₂ appear to have same dissociation limit of NO (X²Π) + O⁻, while the resonance at 8.5 eV appears to dissociate to give NO (a4Π_i) along with O⁻. We find considerable internal excitation of the neutral fragments in all these cases along with that of NF₃, whereas the negative ion resonance in H₂O₂ appears to fragment almost like a diatomic system with very little internal excitation of the OH and OH− fragments.