ABSOLUTE RATE CONSTANTS FOR ATOMIC FLUORINE IN SOLUTION - CHARACTERIZATION OF REACTION INTERMEDIATES IN THE LASER FLASH-PHOTOLYSIS OF XENON DIFLUORIDE

Laser flash photolysis of xenon difluoride in 1,1,2-trichlorotrifluoroethane (Freon-113) yields atomic fluorine, which can be detected via its loose complex with the solvent. This complex, with an absorption maximum at 320 nm, has a lifetime at ambient temperature of about 200 ns and is quenched with rate constants near the diffusion controlled limit by most substrates. In neat hexafluorobenzene as solvent, the heptafluorocyclohexadienyl radical is observed. In addition to the fluorine atom, a second species formed with lambda(max) = 345 nm is assigned to be the XeF radical, with a lifetime of ca. 25 mu s in acetonitrile at ambient temperature.