THE FORMATION OF PAIRS OF WIDELY SPACED METHYL RADICALS FOLLOWING FLUORINE PHOTOLYSIS IN SOLID METHANE AT 10-15 K

Quantum yields of CH3 radicals (Y(R) = 0.95+/-0.2) and CH3F...HF compl exes (Y0 = 0.6+/-0.1), formed by UV photolysis in CH4-F2 solid mixture s (70:1), have been measured using EPR and IR spectroscopy. Since 1/2Y (R) + Y0 congruent-to 1, fluorine atoms do not recombine in a cage; ap proximately half of them are involved in formation of the complexes wh ile the rest gives CH3 radical pairs. The fraction of pairs with an in ter-radical spacing > 20 angstrom is 0.1-0.15.