Photo-initiated oxidation of C-H bonds by diimine complexes of vanadium(v)†

The photochemical activation of carbon-hydrogen bonds by vanadium(v)-dioxo and vanadium(v)-oxo-peroxo diimine complexes is described. Reactions were carried out using a selection of organic substrates with C-H bond dissociation free energy values between 70 and 97 kcal mol(-1). The ability to activate C-H bonds using vanadium(v)-dioxo and vanadium(v)-oxo-peroxo diimine complexes varies with different bond dissociation free energy. Compounds with weaker C-H bonds are oxidized in minutes, rather than in days for thermal oxidations by the corresponding complexes. Dioxygen is necessary for substrate consumption, which suggests that the electronically excited V complexes are radical reaction initiators via H-atom abstraction from the organic substrate.

Automated summary

The photochemical activation of carbon-hydrogen bonds by vanadium(v)-dioxo and vanadium(v)-oxo-peroxo diimine complexes allows for the rapid oxidation of organic substrates with weak C-H bonds, requiring dioxygen for substrate consumption.