Trapping of radical intermediates in the photoreduction of benzophenone

Abstract Radical intermediates formed during the photoreduction of benzophenone by alcohols, amines, phenols, sulphides, thiols, ethers, hydrocarbons and amides have been trapped by t-nitrosobutane and the resulting nitroxide radicals characterized in situ by ESR. In the case of 2,6-di-t-butylphenols and aliphatic sulphides evidence was obtained for radicals other than those expected.