Why is there no in-plane H-atom transfer from aryloxy radicals? A theoretical and experimental investigation

Abstract

A combined experimental and theoretical study of the mechanisms and energies associated with intramolecular H-atom transfers from methyl groups with varying numbers of phenyl substituents to oxygen atoms of aryloxy radicals is reported. It is shown that the transfers within the six aryloxy radicals investigated would have high activation energies and, in all but one case, are endothermic. A detailed analysis of the calculated reaction coordinates indicates proton-coupled electron transfers as the favored mechanisms.