Premium
Aerobic Photooxidation in Water by Polyoxotungstates: The Case of Uracil
Author(s) -
Bonchio Marcella,
Carraro Mauro,
Conte Valeria,
Scorrano Gianfranco
Publication year - 2005
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200500418
Subject(s) - chemistry , photocatalysis , photooxygenation , photochemistry , reactivity (psychology) , selectivity , isostructural , uracil , medicinal chemistry , oxygen , organic chemistry , catalysis , singlet oxygen , medicine , dna , biochemistry , alternative medicine , pathology , crystal structure
Uracil photooxygenation occurs in acidic water (pH = 1) at 25 °C, under oxygen (1 atm), irradiating with λ > 300 nm in the presence of selected polyoxometalates (POM). A marked diversity of photocatalytic behavior is registered for different POMs in terms of oxidation rate and selectivity. H 3 PW 12 O 40 (PW 12 ) appears to be the most reactive photocatalyst, by far superior to isostructural complexes, leading to a product distribution typical of OH · dominated oxidations, while Na 4 W 10 O 32 (W 10 ) and Na 12 [WZn 3 (H 2 O) 2 (ZnW 9 O 34 ) 2 ] (Zn 5 W 19 ) exhibit a preferential reactivity towards uracil glycol. Kinetic studies and radical scavenger probes, performed on target intermediates and model diols, highlight a substantial difference in the mechanism of photocatalysis by the three complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)