Copper oxygen radicals, generation

Organic peroxo compounds are also obtained by autooxidation of ethers, unsaturated hydrocarbons, and other organic materials on exposure to air. A free-radical chain reaction is initiated almost certainly by radicals generated by the interaction of oxygen and traces of metals such as copper, cobalt, or iron. The attack on specific reactive C—H bonds by a radical X" gives first R, then hydroperoxides, which can react further ... 

Copper(I) chloride promotes the oxidation of benzene to phenols with molecular oxygen [37a], The active species is proposed to be a hydroxyl radical generated in the following manner ... 

The catalytic cycle of laccase includes several one-electron transfers between a suitable substrate and the copper atoms, with the concomitant reduction of an oxygen molecule to water during the sequential oxidation of four substrate molecules [66]. With this mechanism, laccases generate phenoxy radicals that undergo non-enzymatic reactions [65]. Multiple reactions lead finally to polymerization, alkyl-aryl cleavage, quinone formation, C> -oxidation or demethoxylation of the phenolic reductant [67]. 

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