Photocatalytic C–H activation and the subtle role of chlorine radical complexation in reactivity

TLDR

Chlorine radicals are highly reactive atoms or molecules with an unpaired electron, and their role is often probed by trapping them with acceptor compounds. The study reinvestigated a photoinduced alkane oxidation reaction previously thought to involve alkoxy radicals. Spectroscopic, kinetic, and isotopic labeling studies showed that chlorine, not alkoxy, is the key radical intermediate, with prior trapping results arising from chlorine complexation with alcohols. Yang et al., Science, doi:10.1126/science.abc8408, p.847.

Abstract

A complex role for chlorine radicals Radicals are atoms or molecules that are highly reactive because they have an unpaired electron. A common means of investigating whether they are involved in a particular reaction is to try to trap them with an acceptor compound. Yang et al. reinvestigated a photoinduced alkane oxidation reaction for which a trapping study had previously implicated alkoxy radicals. Their spectroscopic, kinetic, and isotopic labeling studies revealed that chlorine, rather than alkoxy, was the key radical intermediate; the prior trapping results had stemmed from its complexation with alcohols. Science , abd8408, this issue p. 847