Slow photoelectron velocity-map imaging spectroscopy of C3O− and C3S−

Abstract

High-resolution photodetachment spectra of C3O− and C3S− using slow photoelectron velocity-map imaging spectroscopy are reported. Well-resolved transitions to the neutral X̃ Σ1+ state are seen for both species. The electron affinities of C3O and C3S are determined to be EA(C3O)=1.237±0.003 eV and EA(C3S)=1.5957±0.0010 eV, respectively. Several vibrational frequencies for gas phase C3O and C3S are determined for the first time. The long progression of bending modes observed in the spectra is consistent with electronic structure calculations predicting that the C3O− and C3S− have bent equilibrium geometries.