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

Abstract

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.

Phthalocyanines in Macromolecular Phases - Methods of Synthesis and Properties of the Materials

“…But under irradiation with visible light, much higher amounts of O 2 are consumed and sulfonic acids and sulfate, respectively, are formed (Equation (28), (29)). [118,151,190] Toxic phenol and also chlorinated phenols which are oxidized catalytically only in alkaline aqueous solution to quinones, are photooxidized by visible light radiation under partial mineralization to CO 2 (Equation (30)). [190,191] An example for the synthesis of a chemical was also examined.…”

“…[118,151,190] Toxic phenol and also chlorinated phenols which are oxidized catalytically only in alkaline aqueous solution to quinones, are photooxidized by visible light radiation under partial mineralization to CO 2 (Equation (30)). [190,191] An example for the synthesis of a chemical was also examined. Cyclopentadiene is photooxidized in ethanol solution via the endoperoxide in dependence on the reaction conditions to 4,5-epoxy-2-penten-1-on (Equation (31)) [152,192] Photooxidations were also investigated in the presence of some macromolecular photosensitizers.…”

“…Also sulfur compounds and phenols can be photooxidized under solar light more efficiently. [190] The reason for the high activities in Amberlite comes from the acceleration of the substrates and the monomolecular distribution of phthalocyanine derivatives in the polymer.…”

Synthesis of new carboran-based phthalocyanines and study of their activities in the photooxidation of citronellol

“…The carboranyl substituents do not reduce the photochemical activities. The photocatalytic activities and singlet oxygen quantum yields of the carborane containing phthalocyanines are comparable to the photosensitizer ZnPTS, which is used in the photooxidation of sulfur compounds and phenols [12,[17][18][19]. Partially sulfonated phthalocyanines are also employed as photosensitizers in PDT [7].…”

Porphyrins, phthalocyanines and related systems in polymer phases

“…Covalent binding was also realized on the surface of silica as shown for 2 [16][17][18][19]. Coordinative bonds were obtained by the reaction of silica gel modified with imidazolyl groups and Co-phthalocyanines, and electrostatic bonds with Si-phthalocyanine tetracarboxylic acid at polystyrene-based anion exchangers (examples are 3 and 4) [16][17][18][19]. The loading of the inorganic carriers is of the order of 10 À5 mol g À1 .…”