Ethyl halides radical cations

TABLE 26. ESR parameters for some radical cations formed by irradiation of solutions of ethyl halides in freons... 

If the assumption of this reaction sequence is correct, the photolysis of tetraphenylphosphonium chloride must then only lead to biphenyl, diphenylphosphine, ethyl diphenyl-phosphinate and triphenylphosphine and its oxidation products. After 2 h of irradiation, biphenyl, diphenylphosphine and its oxidation products, triphenylphosphine and triphenylphosphine oxide, in a ratio of 3 1 5, along with raw material, are obtained. Ethyl diphenylphosphinate was detected in trace amounts7. These results support the postulate of the reversibility of phosphoranyl radical formation in such systems and indicate one-electron transfer processes15 in the formation and decomposition of the tetraarylphosphonium cation. This reaction is comparable to the observation of an electron transfer from halide ions to hydroxyl radicals or hydrogen atoms in aqueous solutions16,... 

In spite of the favourable steric arrangement, propargyl cations, although more stable than vinyl and ethyl cations, are less stable than allyl cations. This is indicated by the ionization potentials of the simple parent radicals, 8-25 and 8-16 eV (Lossing, 1963) respectively, and by the lower (by a factor of ca. 104) rate of unimolecular solvolysis in ethanol-water 4 1 of propargyl (174) than of allyl halides (175) (Burawoy and... 

The cationic polymerization of alloocimene, also ocimene and myrcene, has been achieved with metal halide catalysts (e.g., stannic chloride, aluminum chloride, or boron trifluoride) in liquid phase (e.g., ethyl chloride, ethylene dichloride, or benzene) at a temperature range of —35°C to about 200°C. MWs and microstructures of the products were not provided [40]. Cationic (or radical) copolymerizations of alloocimene (or myrcene) with for instance styrene yield resinous copolymers [42]. 

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