Reactions of Thiyl Radicals. X. Photolysis of Ethyl Sulfide Vapor

Abstract

The photolysis of ethyl sulfide vapor at 2537 Å has been investigated as a function of substrate and CF4 pressure, time, and temperature. Reaction products with quantum yields in parentheses are ethyl disulfide (0.178), ethane (0.138), butane (0.086), ethanethiol (0.096), 4-methyl-3-thiahexane (0.034) and 4-methyl-3,5-dithiaheptane.Ethyl and ethylthiyl radicals are formed in the primary process and the product yields indicate a net primary decomposition quantum yield of 0.48. A reaction mechanism involving subsequent reactions of the primary fragments is proposed and explains the observed products and the observed variation in rates. Excited radicals and hot radical combination products play a minor role in this system, in contrast to the behavior of lower molecular weight sulfides. Secondary photolysis of the disulfide produced and consumption of ethanethiol are important factors in determining the time dependence of reaction rates in this system.