Vacuum ultraviolet photodissociation of SH radical at 121.6 nm

Abstract

Vacuum ultraviolet (VUV) photodissociation of jet-cooled SH radical is studied at the photolysis wavelength of 121.6 nm using high- n Rydberg atom time-of-flight (HRTOF) technique. Both the ground-state S( 3P J ) and the excited-state S( 1D 2) and S( 1S 0) products are observed, with a branching fraction of S( 3P J ):S( 1D 2):S( 1S 0) = 0.07 ± 0.01:0.82 ± 0.01:0.11 ± 0.01. The spin–orbit branching fraction of the minor S( 3P J ) product is S( 3P 2):S( 3P 1):S( 3P 0) = 0.28 ± 0.12:0.54 ± 0.16:0.18 ± 0.09. The predominant production of S( 1D 2) is consistent with a direct dissociation from the repulsive 2 2Π state. The S( 3P J ) product fine-structure state distribution from SH photodissociation at 121.6 nm is significantly different from that in the UV region.