High Temperature Reaction of S + SO2 → SO + SO: Implication of S2O2 Intermediate Complex Formation

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2003-12, Vol.107 (50), p.10996-11000
• Main Authors: Murakami, Yoshinori, Onishi, Shouichi, Kobayashi, Takaomi, Fujii, Nobuyuki, Isshiki, Nobuyasu, Tsuchiya, Kentaro, Tezaki, Atsumu, Matsui, Hiroyuki
• Format: Article
• Language: English
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp030471i

The rate constant for the reaction S + SO2 → SO + SO (1) has been investigated by measuring time profiles of S atoms behind reflected shock waves using two experimental systems:  S atoms were provided by the thermal decomposition of COS in the high-temperature range (2020−2800 K) and by excimer laser photolysis of COS in the low-temperature range (T = 1120−1540 K). The results of these experiments yield the rate constant with a non-Arrhenus temperature dependence, k 1 = 10-39.73 T 8.21 exp(4828.5/T) cm3 molecules-1 s-1, over the extended temperature range (1120−2800 K). By comparing the rate constants with that derived from a conventional transition-state theory based on the potential energy surface calculated by the G2M(CC1) methodology, a reaction mechanism including a contribution of the singlet state of the reaction intermediate S2O2 is discussed.