Photodissociation dynamics of H2S+ near 325 nm

Abstract

We study the photodissociation dynamics of the hydrogen sulfide cations (H2S+) using the time-sliced velocity map ion imaging (VMI) technique and high-accuracy calculations. High-resolution ion images of the S+(4S) products were measured at four photolysis wavelengths of 325.158, 325.200, 325.243, 325.307 nm, which correspond to the excitation to the A2A1(0,13,0) K=1 state of H2S+. Rotational state-resolved total kinetic energy releases and angular distributions have been derived as a function of the photolysis wavelengths. Notably, photolysis wavelength dependent product rotational state and anisotropy parameter distributions have been clearly observed. Full-dimensional potential energy surface characterization suggests that nonadiabatic coupling between A2A1 and B2B2 states at C2v configurations, as well as relaxation of the symmetry to Cs in the conical intersection region between the two states, plays a key role in the photodissociation process.