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

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