RADICAL-RADICAL REACTIONS IN DIFFERENT SOLVENTS . PROPYL, CYCLOHEXYL, AND BENZYL RADICALS

Rate constants for radical-radical reactions involving the propyl, cyclohexyl, and benzyl radicals have been determined in both cyclohexane and benzene. Steady-state radical concentrations were monitored using the thiol-triethyl phosphite reaction, and rate constants for the reaction R· + RSH → RH + RS· were also obtained. Both kR· + R· and kR· + RSH when measured in cyclohexane are larger than or equal to those found in benzene. The solvent effect is greatest for the propyl radical and essentially nonexistent for the benzyl radical with cyclohexyl intermediate in behavior. The results can be rationalized by using the assumption that the alkyl radicals interact with benzene to form a complex species.