PULSE-RADIOLYSIS, FLASH-PHOTOLYSIS, AND SHOCK-WAVE STUDY OF THE RECOMBINATION H + BENZYL-]TOLUENE AT 300-K AND 1300-1650-K

Pulse radiolysis, discharge flash photolysis, and laser flash photolysis have been employed to study the recombination reaction H + benzyl → toluene at room temperature. Both H atoms and benzyl radicals were monitored. The same reaction was studied directly in shock waves between 1300 and 1650 K. The value of the high-pressure recombination rate constant of (2.5 ± 0.8) × 1014 cm3 mol-1 s-1 was found to be independent of the temperature between 300 and 1650 K. It is argued that high-pressure rate constants for other recombination reactions should also have very small temperature coefficients over wide temperature ranges. Room temperature rate constants for addition of H atoms to toluene, cycloheptatriene, p-xylene, benzene, phenyl, and p-methylbenzyl are also reported. © 1990 American Chemical Society.