Two-photon dissociation dynamics of the SH/SD radicals are investigated using the high-n Rydberg atom time-of-flight (HRTOF) technique. The H/D(2S) + S(1D) and H/D(2S) + S(1S) products are observed in the dissociation of the SH/SD radicals on the 22Π and B2Σ+ repulsive states, from sequential two-photon excitation via the A2Σ+ (v' = 0, J' = 0.5-2.5) state. The angular distributions of both H/D(2S) + S(1D) and H/D(2S) + S(1S) product channels are anisotropic. The anisotropy parameter (β) of the H(2S) + S(1D) products is ~ −0.8 ± 0.1 (−0.9 ± 0.05 for SD), and that of the H(2S) + S(1S) products is ~ 1.3 ± 0.3 (1.2 for SD). The anisotropic angular distributions indicate that the SH/SD radicals promptly dissociate on the repulsive 22Π and B2Σ+ potential energy curves (PECs) along with some non-adiabatic crossings, leading to the H/D(2S) + S(1D) and H/D(2S) + S(1S) products, respectively. The bond dissociation energy of the ground-state X2Π3/2 SH/SD to the ground-state H/D(2S) + S(3P2) products is measured to be D0(S−H) = 29253 ± 20 cm−1 and D0(S−D) = 29650 ± 20 cm−1, respectively. The dissociation energy of the A2Σ+ state SH/SD to the H/D(2S) + S(1D) products is derived to be D0[S−H(A)] = 7659 ± 20 cm−1 and D0[S−D(A)] = 7940 ± 20 cm−1.

Two-photon dissociation dynamics of the mercapto radical

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