Photodissociation dynamics of H2S+ near 325 nm

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+(S-4) products were measured at four photolysis wavelengths of 325.158, 325.200, 325.243, 325.307 nm, which correspond to the excitation to the A(2)A(1)(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 A(2)A(1) and (BB2)-B-2 states at C-2v configurations, as well as relaxation of the symmetry to C-s in the conical intersection region between the two states, plays a key role in the photodissociation process.

Automated summary

The photodissociation dynamics of H2S+ were studied using the VMI technique and high-accuracy calculations. Ion images of S+(S-4) products were measured at different photolysis wavelengths. The product rotational state and anisotropy parameter distributions were found to be dependent on the photolysis wavelength. Nonadiabatic coupling and symmetry relaxation were identified as key factors in the photodissociation process.