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Titolo:
Photocatalyzed degradation of polymers in aqueous semiconductor suspensions. IV - Theoretical and experimental examination of the photooxidative mineralization of constituent bases in nucleic acids at titania/water interfaces
Autore:
Horikoshi, S; Serpone, N; Yoshizawa, S; Knowland, J; Hidaka, H;
Indirizzi:
Iwaki Meisei Univ, Frontier Res Ctr, Tokyo 1918506, Japan Iwaki Meisei Univ Tokyo Japan 1918506 tier Res Ctr, Tokyo 1918506, Japan Concordia Univ, Dept Chem & Biochem, Montreal, PQ H3G 1M8, Canada Concordia Univ Montreal PQ Canada H3G 1M8 m, Montreal, PQ H3G 1M8, Canada Univ Oxford, Dept Biochem, Oxford OX1 3QU, England Univ Oxford Oxford England OX1 3QU Dept Biochem, Oxford OX1 3QU, England Iwaki Meisei Univ, Dept Chem, Tokyo 1918506, Japan Iwaki Meisei Univ Tokyo Japan 1918506 v, Dept Chem, Tokyo 1918506, Japan
Titolo Testata:
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
fascicolo: 1, volume: 120, anno: 1999,
pagine: 63 - 74
SICI:
1010-6030(19990104)120:1<63:PDOPIA>2.0.ZU;2-9
Fonte:
ISI
Lingua:
ENG
Soggetto:
PESTICIDE PERMETHRIN; TIO2 SEMICONDUCTOR; ESCHERICHIA-COLI; PHOTODEGRADATION; SURFACTANTS; DISPERSIONS; CELLS; STERILIZATION; INACTIVATION; PARTICLES;
Keywords:
photooxidation; photodegradation; pyrimidine base; purine base; molecular orbital calculations; photocatalysis; titanium dioxide;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
29
Recensione:
Indirizzi per estratti:
Indirizzo: Hidaka, H Iwaki Meisei Univ, Frontier Res Ctr, 2-1-1 Hodokubo, Tokyo 1918506, Japan Iwaki Meisei Univ 2-1-1 Hodokubo Tokyo Japan 1918506 506, Japan
Citazione:
S. Horikoshi et al., "Photocatalyzed degradation of polymers in aqueous semiconductor suspensions. IV - Theoretical and experimental examination of the photooxidative mineralization of constituent bases in nucleic acids at titania/water interfaces", J PHOTOCH A, 120(1), 1999, pp. 63-74

Abstract

The mechanistic sequence(s) in the TiO2-photocatalytic oxidation of constituent pyrimidine and purine bases in nucleic acids is examined theoretically by molecular orbital calculations of frontier electron densities and point charges on all atoms, and experimentally by UV-Vis spectroscopy and gas chromatography to assess how the chemical structure of the bases affects their photocatalyzed mineralization. Rates of formation of NH4+ and NO3- ions in the pyrimidine bases are closely dependent on the existence of the carbonyl and amino groups; for example, formation of NO3- ions is faster than formation of NH4+ ions for uracil (Ura) and thymine (Thy) having the carbonylfunction. By contrast, NH4+ ions are produced faster than NO3- ions in thecase of cytosine (Cyt) which possesses a primary amine function. In comparison with uric acid, which has no amino group, the photocatalyzed mineralization of the purine bases adenine (Ade) and guanine (Gua) generates a greater quantity of NH4+ ions than NO3- ions, in the initial stages. In nearly all cases examined, formation of NO3- ions takes place only after an induction period and originates mostly from the ring nitrogen atoms of the bases. (C) 1999 Elsevier Science S.A. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 13/07/20 alle ore 18:11:13