Photolysis of, and the reactions of H-atoms with, isopropanethiol

• Published in: Canadian journal of chemistry Vol. 66; no. 8; pp. 2025 - 2033
• Main Authors: Lam, W. W, Yokota, T, Safarik, I, Strausz, O. P
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 01.08.1988; National Research Council of Canada
• Subjects: Chemistry; Exact sciences and technology; General and physical chemistry; Photochemistry; Physical chemistry of induced reactions (with radiations, particles and ultrasonics)
• ISSN: 0008-4042; 1480-3291
• DOI: 10.1139/v88-326

Detailed investigation of the photolysis of i-C 3 H 7 SH has been carried out in the absence and presence of the inert gas, n-C 4 H 10 . A mechanism consisting of three primary photochemical steps: , ; , ; , ; six hot reaction steps and seven thermal reaction steps adequately explains all the experimental observations. As in the case of hot H* atoms both the H-atom abstraction, , and the SH-displacement, , reactions occur with thermalized H-atoms, with the rate constant ratio k 7 /k 8  = 19.2 ± 4.3 at 25 °C. The Arrhenius expressions have been determined over the temperature range 25-145 °C, to be: k 7  = (4.0 ± 0.7) × 10 12 exp [(−1066 ± 43)/RT] and k 8  = (2.8 ± 0.6) × 10 12 exp[(−2597 ± 114)/RT] cm 3 mol −1 s −1 . It was found that the overall mechanism for the photolytic decomposition of i-C 3 H 7 SH is analogous to that established for C 2 H 5 SH in previous investigations.