Resonance enhanced multiphoton ionisation spectroscopy of dimethyl sulfide

Abstract

We report the first multiphoton study of the electronic spectrum of the dimethyl sulfied molecule. The interpretation we present is based on analysis of the two-and three-photon resonance enhanced multiphoton ionisation (REMPI) spectra and measurements of the kinetic energies of the photoelectrons resulting from the REMPI process. Members of four (possibly five) Rydberg series are identified and a refined value of the first ionisation limit of dimethyl sulfied is obtained: E_i= 8.710 ± 0.005 eV (70 250 ± 40 cm^–1). As in our previous study of the related divalent sulfide methanethiol, we detect the presence of slower electrons in the photoelectron spectra which can be interpreted in terms of near resonant inter-Rydberg state vibronic mixing.