Ultraviolet photodissociation of the SD radical in vibrationally ground and excited states
Abstract
Ultraviolet (UV) photodissociation dynamics of the SD radical in vibrationally ground and excited states (X 2Π3/2, v″ = 0–5) are investigated in the photolysis wavelength region of 220 to 244 nm using the high-n Rydberg atom time-of-flight (HRTOF) technique. The UV photodissociation dynamics of SD (X 2Π3/2) from v″ = 0–5 are similar to each other and to that of SH studied previously. The anisotropy parameter of the D-atom product is ∼−1; the spin–orbit branching fractions of the S(3PJ) products are essentially constant, with an average S(3P2) : S(3P1) : S(3P0) = 0.51 : 0.37 : 0.12. The UV photolysis of SD is a direct dissociation from the repulsive 2Σ− state following the perpendicular 2Σ−–X 2Π excitation. The S(3PJ) product fine-structure state distributions approach that in the sudden limit dissociation on the single repulsive 2Σ− curve, but they are also affected by nonadiabatic couplings among the repulsive 4Σ−, 2Σ−, and 4Π states. A bond dissociation energy D0(S–D) = 29 660 ± 25 cm−1 is obtained.
- This article is part of the themed collection: Electronic structures and reaction dynamics of open-shell species