Rotationally resolved nonresonant two-photon ionization of SH

Abstract

The threshold photoelectron (PE) spectrum for nascent SH formed in the ultraviolet photodissociation of H2S has been measured using the nonresonant two-photon pulsed field ionization (N2P-PFI) technique. The rotationally resolved N2P-PFI-PE spectrum of SH indicates that photoionization dynamics favor the rotational angular momentum change ΔN≤0 with the ΔN values up to −3, an observation similar to that found in the PFI-PE spectra of OH (OD) and NO. The ionization energy for SH(X 2Π3/2) is determined to be 84 057.5 ± 3 cm−1 (10.4219 ± 0.0004 eV). The spin–orbit splitting for SH(X 2Π3/2,1/2) is 377 ± 2 cm−1, in agreement with the literature value. This study illustrates that the PFI-PE detection method can be a sensitive probe for the nascent internal energy distribution of photoproducts.