Interaction of low-energy electrons with dimethyl sulfide and dimethyl disulfide

Abstract

We report elastic integral cross sections for low-energy electron scattering by gas-phase dimethyl sulfide and dimethyl disulfide, obtained with the Schwinger multichannel method with pseudopotentials. Our symmetry-resolved cross sections for dimethyl sulfide reveal that the single broad structure at $3.25\phantom{\rule{0.16em}{0ex}}\mathrm{eV}$ observed in the electron transmission spectrum (assigned as a ${\ensuremath{\sigma}}_{\mathrm{CS}}^{*}$ shape resonance) would actually arise from two superimposed anion states in the ${B}_{2}$ and ${A}_{1}$ symmetry components of the ${C}_{2v}$ point group. We also obtained two low-lying shape resonances for dimethyl disulfide, in good agreement with the available electron transmission data. In view of the recently reported measurements on dissociative electron attachment to dimethyl disulfide [C. Matias, A. Mauracher, P. Scheier, P. Lim\~ao-Vieira, and S. Denifl, Chem. Phys. Lett. 605-606, 71 (2014)], we also calculated cross sections for stretched S--S bond lengths, which indicate a fast stabilization consistent with the experimental data.