Cross-disproportionation to combination ratios for CF2H and n-C3H7 radicals have been determined (the hydrogen acceptor radical is given first) to be A(n-C3H7,CF2H) = 0.30 2 0.01 and A(CF2H, n-C3H7) = 0.057 ? 0.006.

Three complexes were obtained during reactions of 6-amino-1-methyl-5-nitrosouracil, 6-methylamino-1-methyl-5-nitrosouracil and 6-methylamino-1-benzyl-5-nitrosouracil with K 2 PtCl 4 . The complexes were isolated in good yields as powdery precipitates and characterized through elemental analysis, infrared and 1 H NMR spectroscopies, and thermal analysis. The pyrimidine bases easily substitute chloro ligands as a neutral monodentate ligand form. The exocyclic oxygen atoms are the probable binding sites rather than ring or exocyclic nitrogen atoms. trans Square planar structures were proposed in all cases.

A redetermination of the disproportionation/combination ratio for n-CsF7 and CzH5 radicals gives a value of A(n-C3F7, CtH,) = 0.13 t 0.01, independent of the temperature. The radicals were produced by the photolysis of n-C3F&OC2Hs. The previous determinations of this ratio are discussed and are found to be largely incorrect. The values for A(CF3, CzH5) and A(CzF5, C2H5) are also re-evaluated, and the recommended values are 0.10 2 0.02 and 0.12 t 0.02, respectively. Systems involving perfluoroalkyl and ethyl radicals are complicated due to rapid perfluororadical addition to the ethylene formed in the disproportionation process. The extent of this reaction, and its consequences, are discussed and evaluated. The role of the propionyl (C2H5CO) radical in the room temperature photolysis is also assessed. However, it is found that the A values determined by the intercept method used in this work are not affected by the secondary reactions that occur. It is concluded that high cross-combination ratios are general to perfluoroalkyl-alkyl radical interactions. For C3F7 and CzHs radicals the ratio is 2.7-2.8. Above 100°C ratios exceed 3 due to secondary reactions.

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ChemInform Abstract (generated by photolysis of n-C3F7-CO-C2H5).