Mixtures of 1,1,3,3-tetrafluoroacetone and perf luorodi-n-propyl ketone have been photolyzed together over the temperature range 50" to 200"C, and the disproportionation/combination ratio for n-C3F7 and CFzH radicals has been determined to be A(n-CsF7, CFZH) = 0.072 ? 0.003. A reevaluation of existing data on CH3 and CFzH radicals leads to a value of A(CH3, CFzH) = 0.35. The large variations in A for the reactions of alkyl and perfluoroalkyl radicals with CFzH radicals are discussed. 0 1992 John Wiley & Sons, Inc.