Direct Detection of S(P-3) and S(D-1) Generated in the O(D-1) + OCS Reaction: Mechanism of the Formation of S-2(X-3 Sigma(-)(g) and a(1)Delta(g))

作者：Tanimoto Haruka; Tendo Shogo; Orimi Kenichi; Goto Hiroki; Kohguchi Hiroshi; Yamasaki Katsuyoshi^*

来源：Journal of Physical Chemistry A, 2018, 122(8): 1948-1953.

DOI：10.1021/acs.jpca.7b11375

Highly vibrationally excited disulfur S-2 in the X-3 Sigma(-)(g) and a(1)Delta(g) states has been detected in the gaseous mixture of O-3 and OCS irradiated with light at 266 nm. Generation of CO2 in the reaction system has been reported; however, no direct detection of sulfur atoms (S(P-3) and S(D-1)) has been made. In the present study, we have employed the two-photon laser-induced fluorescence (2P-LIF) technique to detect S(P-3) and S(D-1) directly and recorded the time profiles of the atoms at varying pressures of OCS. Kinetic analyses of the profiles show that (i) S(D-1) is generated in the O(D-1) + OCS reaction and consumed by the S(D-1) + OCS reaction, and (ii) S(P-3) is mainly generated in the O(D-1) + OCS reaction instead of quenching of S(D-1) by collisions with OCS and ambient gases. The vibrational levels v = 19 and 10 of the respective electronic states X-3 Sigma(-)(g) and a(1)Delta(g) of S-2 were detected in the O-3/OCS/266 nm system. The two vibrational levels cannot be generated by the available energy of the S(P-3) + OCS reaction, giving evidence that S-2 in the X-3 Sigma(-)(g) and a(1)Delta(g) states are generated by the S(D-1) + OCS reaction.

• 出版日期2018-3-1