Resonance energy alkyl free radicals

The reaction requires only very small activation energies, and, so, can even be used to start free radical polymerizations at —100°C. The alkyl free radicals produced are particularly poorly resonance stabilized, and so, can undergo a series of side reactions, for example, transfer reactions. 

The rapidity of the reaction can be seen by the large effect low pressures ( 1 torr) of oxygen can have on the free radical polymerization of a reactive olefin such as styrene [22]. The reaction rate coefficients are expected to be typical for exothermic radical—radical reactions with essentially no activation energy. Thus, if R is alkyl, log(feQ/l mole-1 s-1) would be 9.0 0.5, and be independent of temperature. For simple resonance-stabilized radicals, log(feD/l mole-1 s-1) would be 8.5 0.5. 

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