Reactivity of aliphatic compounds towards hydroxyl radicals

The rates of reaction of hydroxyl radicals with a large number of aliphatic compounds have been determined. These include carboxylate ions, alcohols, glycols, and ethers, as well as two series of substituted methanes and acetate ions. The reactivities of aliphatic compounds towards OH radicals are dependent on both the inductive and the resonance effects, as expressed by Hammett's σ-function. The reactivities of long-chain compounds are the sum of the partial reactivities of C-H bonds at different positions in the molecule. This corroborates the assumption that the general pattern of reactions of OH radicals with aliphatic compounds involves the abstraction of H atoms in the rate-determining step. Only in specific cases was a charge-transfer mechanism indicated. A general parallelism is observed between the reactions of OH radicals and those of H atoms.