EPR studies on H-abstraction from methylbenzenes by “magic blue” reagent

After mixing a methylbenzene 4 with “magic blue” solution in F113 (CClF2CCl2F) containing bis{perfluoro[1-(2-fluorosulfonyl)ethoxy]ethyl}nitroxide 2 and perfluoro-1-nitroso-1-[1-(2-fluorosulfonyl)ethoxy]ethane 3 at room temperature, benzylic H-atom of 4 could be selectively abstracted by 2, and benzyl radical 5 thus generated was immediately trapped by 3. Based on hyper-fine splitting constants (hfsc), the structure of the spin adducts perfluoro[1-(2-fluorosulfonyl)ethoxy]ethyl benzyl nitroxides 6 derived from seven methylbenzenes have been identified. The mechanism of the H-abstraction/spin trapping process is also discussed.