Ionic and radical processes in the γ radiolysis of tetrahalomethane-arene gaseous mixtures

The reactivity and selectivity of radiolytically (60Co γ rays) generated unsolvated CF3+ toward selected arom. substrates were measured under conditions where nonionic processes can be ruled out. The same situation could not be attained for CCl3+, owing to the interference of •CCl3, the major reactive species produced by γ radiolysis of CCl4(g). Unsolvated CF3+ is a moderate electrophile whose attack on differently substituted arom. substrates is rather indiscriminate; its positional selectivity toward PhMe (para/0.5 meta = 4.3) appears intermediate between that of i-C3H7+ (para/0.5 meta = 2.7) and that of the very mild t-C4H9+ (para/0.5 meta = 35).