The trapping of carbon radicals. The competition of oxygen and iodine for the 1,1-diphenylethyl radical

Abstract

Carbon-centred radicals react rapidly with oxygen and numerous radical-scavenging compounds. The competition between oxygen and radical scavengers for a tertiary alkyl radical has been studied under conditions that simulate the initiation step of a hydrocarbon autoxidation. Iodine effectively captures the 1,1-diphenylethyl radical give in the presence of oxygen, the resultant alkyl iodide undergoing decomposition by loss of hydrogen iodide to give the corresponding olefin. An approximate value of k(O₂)/k(I₂)= 6 for the relative reactivity of the 1,1-diphenylethyl radical towards oxygen and iodine has been obtained.