Photooxidation of sulfide, thiol, phenols, and cyclopentadiene by artificial light and solar light irradiation

Abstract

The photooxidations of the toxic products sulfide, 2-mercaptoethanol and phenols under partial mineralisation in aqueous alkaline solution and the photooxidation of cyclopentadiene in ethanol in order to produce fine chemicals is described. Because the employed photosensitizers such as metal phthalocyanines, a tetraphenylporphyrine, rose bengal or methylene blue absorb in the visible region of light, an inexpensive slide projector was used under laboratory conditions.Experiments under solar radiation were carried out by concentrating the solar light with a reflective satellite bowl. The oxygen consumption over time is measured with a gas burette. The formation of singlet oxygen by energy transfer from the excited photosensitizer followed by oxidation of the substrates is responsible for the photoinduced oxidations. The applicability of the experimental conditions described here for other visible and solar light driven oxidation reactions is obvious.