Phototochemistry of cation radicals in solution; photoinduced electron-transfer reactions between alcholos and the N,N,N′,N′,-tetraphenyl-p-phenylenediamine cation radical

Irradiation of the N,N,N′,N′-tetraphenyl-p-phenylanediamine cation radical (TPPD·+) with benzyl alchohol causes its reduction to TPPD and oxidation of the alcohol into benzaldehyde; with benzhydrol and 1-phenylethanol the corresponding symmetrical ethers are formed in a photocatalytic process in which TPPD·+ is recycled via two successive electron transfers.