The absolute rate constants for the addition of alkyl radicals to acrylonitrile and methyl acrylate are determined by evaluating the ratio of ligand-transfer oxidation and addition to the double bond. Secondary alkyl radic ̵ als appear to be more reactive than primary alkyl radicals, despite the less favourable energetics. The classical selectivity: reactivity relationship is reversed owing to the nucleophilic character of the alkyl radicals.
