QUANTUM YIELDS OF INTRAMOLECULAR HYDROGEN ABSTRACTION INDUCED BY LASER FLASH-PHOTOLYSIS OF ARENE CL PI-COMPLEXES/

Arene/chlorine atom pi-complexes were generated by pulse radiolysis of a wide variety of substituted benzenes in carbon tetrachloride at roo m temperature. Upon laser flash photolysis of the pi-complexes, intram olecular hydrogen abstraction was observed in times much shorter than the flash time (6 ns), with quantum yields between 0.05 and 0.18 depen ding on the sort and the number of the substituents but not on their p ositions. The effects of substituents on the photochemistry of arene/c hlorine atom pi-complexes were discussed in connection with the bond d issociation energy of the related atoms and with the structure of the pi-complexes.