Thiirene formation in the reactions of sulfur atoms with alkynes

• Published in: Canadian journal of chemistry 1983-10, Vol.61 (10), p.2268-2281
• Main Authors: Verkoczy, Bela, Sherwood, Alden G, Safarik, Imre, Strausz, Otto P
• Format: Article
• Language: English
• Subjects: Chemistry; Exact sciences and technology; Kinetics and mechanisms; Organic chemistry; Reactivity and mechanisms
• ISSN: 0008-4042; 1480-3291
• DOI: 10.1139/v83-393

The gas phase reactions of S( 1 D 2 ) and S( 3 P J ) atoms with alkynes have been studied by photolyzing COS in the presence of CH≡CH, CF 3 C≡CH, and CF 3 C≡CCF 3 . In the reactions with CH≡CH, CS 2 , benzene, and thiophene were formed; with CF 3 C≡CH, eight products were found with disubstituted thiophenes and trisubstituted benzenes as the major products. In the case of CF 3 C≡CCF 3 , only perfluorotetramethylthiophene was detected at low conversion but at long photolysis several new products were observed. Many of the reaction products characterized here have not been reported before.The formation and distribution of the reaction products could be rationalized by an overall mechanism in which the formation of the highly reactive primary adducts, thiirene and thioformylmethylene, is followed by bimolecular reactions yielding the principal end products. The formation of minor products could be explained by secondary photoisomerizations, secondary photolysis, and by secondary decompositions and the secondary reactions of sulfur atoms with primary products.