Regioselectivity in the Semiconductor-Mediated Photooxidation of 1,4-Pentanediol

Article abstract of DOI:10.1021/jo00277a021

Optimum conditions have been established for the selective semiconductor-photocatalyzed oxidation by long-wavelength ultraviolet light of the primary alcohol functionality in 1,4-pentanediol.On platinized (2percent) TiO2 powder suspended in oxygenated aqueous (4 vol percent) acetonitrile, the initial rate ratio for oxidation of the primary/secondary alcohol site was > 7.Analysis of further oxidation products allowed for mechanistic delineation of the course of the semiconductor-mediated reaction.The selectivity is attributed to the essential role of adsorption, with the criticalphotoinduced electron transfer occurring at the surface of the irradiated particle.ZrO2 and SnO2 samples were much less active than TiO2 as photocatalysts.The effects of oxygen pressure, metal cocatalyst loading, and water content of acetonitrile are discussed.