Vacuum ultraviolet photodissociation dynamics of OCS via the F Rydberg state: The O (3PJ=2,1,0) product channels.

ABSTRACT

We study the vacuum ultraviolet (VUV) photodissociation dynamics of carbonyl sulfide (OCS) by using the time sliced velocity map ion imaging technique. Experimental images of the dissociative O (3PJ=0,1,2) products were acquired at five VUV photolysis wavelengths from 133.26 to 139.96 nm that correspond to the F Rydberg state of OCS. High vibrational states of the carbon monosulfide (CS) co-products are partially resolved in the images. The product total kinetic energy releases, angular distributions, and the product state branching ratios were derived from the experimental images. Notably, it is found that the anisotropic parameters change systematically with the photolysis wavelength. The anisotropic parameters and the product state branching ratios are significantly sensitive to the J quantum number of the O (3PJ) products. The phenomenon indicates that multiple nonadiabatic pathways are strongly involved in the photodissociation processes.