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Photodegradation of atrazine and ametryn with visible light using water soluble...
Rebelo, Susana; Melo, A.; Coimbra, R.; Azenha, M.; Pereira, Mariette; Burrows, Hugh; Sarakha, MohamedAbstract The photodegradation of the herbicides atrazine and ametryn with visible light in aerated neutral aqueous solutions and 5, 10, 15, 20-tetrakis (2,6-dichloro-3-sulfophenyl) porphyrin or 5, 10, 15, 20-tetrakis (4-sulfophenyl) porphyrin as sensitizers are reported for the first time. Our findings show that the degradation percentage reached 30% for atrazine and 63% for ametryn. The final photoproducts we...
Oxidation of Δ4- and Δ5-Steroids with Hydrogen Peroxide Catalyzed by Porphyrin ...
Rebelo, Susana L. H.; Simões, Mário M. Q.; Neves, M. Graça P. M. S.; Silva, Artur M. S.; Cavaleiro, José A. S.; Peixoto, Andreia F.In this paper we describe a new environmentally friendly method to promote the stereoselective epoxidation of Delta4- and Delta5-steroids. Metalloporphyrins efficiently catalyze the epoxidation reactions of 17beta-acetoxy-4-androstene (1), 4-cholestene (2) and 3beta-acetoxy-5-cholestene (3) in the presence of H2O2 as oxygen donor. Modeling the molecular structure of the porphyrin as well as the central metal al...
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