Nascent vibrational distributions of S2X3Σg- generated in the S(1D) + OCS reaction and vibrational relaxation by collisions with He and CF4

Abstract Disulfur S 2 X 3 Σ g - was generated by irradiation of the pulsed laser light at 248 nm to the gaseous OCS. Single vibrational level of S 2 X 3 Σ g - , v = 0 - 4 was detected with laser-induced fluorescence (LIF) via the B 3 Σ u -  −  X 3 Σ g - transition. The kinetic analysis of the time-resolved LIF intensities recorded at varying pressures of CF4 has given the rate coefficients kv for vibrational relaxation of S 2 X 3 Σ g - , v to be kv/10−12 cm3 molecule−1 s−1 = 0.25 ± 0.07, 0.63 ± 0.06, and 1.2 ± 0.2 for v = 1, 2, and 3, respectively. The analysis also determined the relative detectabilities of the adjacent vibrational levels, deriving the nascent relative vibrational populations of the levels v = 0/1/2/3 to be 1/0.69 ± 0.05/0.47 ± 0.06/0.49 ± 0.07.