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Pregled bibliografske jedinice broj: 135939

Oxidation of Hydroxyurea with Oxovanadium(V) Ions in Acidic Aqueous Solution


Gabričević, Mario; Bešić, Erim; Biruš, Mladen; Zahl, Achim; van Eldik, Rudi
Oxidation of Hydroxyurea with Oxovanadium(V) Ions in Acidic Aqueous Solution // Journal of Inorganic Biochemistry, 100 (2006), 10; 1606-1613 doi:10.1016/j.jinorgbio.2006.05.008 (međunarodna recenzija, članak, znanstveni)


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Naslov
Oxidation of Hydroxyurea with Oxovanadium(V) Ions in Acidic Aqueous Solution

Autori
Gabričević, Mario ; Bešić, Erim ; Biruš, Mladen ; Zahl, Achim ; van Eldik, Rudi

Izvornik
Journal of Inorganic Biochemistry (0162-0134) 100 (2006), 10; 1606-1613

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Dioxovanaium(V); Hydroxyurea; Redox; Mechanism; EPR spectroscopy

Sažetak
Hydroxyurea (HU) effectively reduces vanadium(V) into vanadium(IV) in acid aqueous solution via the formation of a transient complex species followed by the electron transfer process including the formation and subsequent fading out of a free radical. The measured g-value of the radical (g = 2.0067) shows that the unpaired electron is located predominantly in the p-orbital of the hydroxamate hydroxyl-oxygen atom. The visible and VIV-EPR spectroscopic data indicate that HU acts as a two-electron donor. The studied redox reaction can be delineated as: 2VVO2+ + HU ? ; ; ; 2VIVO2+ + products. FTIR data reveal that one of the products is isocynate, but there is no evidence of NO as the product. The 51V-NMR spectral data indicates protonation of dioxovanadium(V) ions according to equation ; and value of K calculated as 0.7 M-1. Spectrophotometric titration data of V(V)-HU system reveal following equilibria ; characterized by K0 = 5 M-1 and K1 = 22 M-1. When HU is in molar excess, and the above three reactions featuring fast equilibria, the following inner-sphere electron-transfer mechanism satisfies the kinetic experiments: (H2O)3VVOU2+ ? ; ; ; (H2O)3VIVOU? ; ; ; 2+ (slow, k1) (H2O)3VIVOU? ; ; ; 2+ + 2H2O ? ; ; ; (H2O)5VIVO2+ + U? ; ; ; (fast) U? ; ; ; + (H2O)4VVO2+ ? ; ; ; (H2O)5VIVO2+ + products (fast) characterized by k1 = 1.4 s-1. When V(V) is in excess, two outher-sphere electron-transfer pathways must be added: (H2O)3VVOU2+ + (H2O)4VVO2+ ? ; ; ; (H2O)3VVOU? ; ; ; 3+ + (H2O)4VIVO2 k4 (H2O)3VVOU2+ + (H2O)4VVO(OH)2+ ? ; ; ; (H2O)3VVOU? ; ; ; 3+ + (H2O)4VIVO(OH)+ k5 characterized by k4 = 22 s-1 mol-1 dm3, and k5 = 3.8 × 103 s-1 mol-1 dm3.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija



POVEZANOST RADA


Projekt / tema
0006441

Ustanove
Farmaceutsko-biokemijski fakultet, Zagreb

Profili:

Avatar Url Mario Gabričević (autor)

Avatar Url Erim Bešić (autor)

Avatar Url Mladen Biruš (autor)

Citiraj ovu publikaciju

Gabričević, Mario; Bešić, Erim; Biruš, Mladen; Zahl, Achim; van Eldik, Rudi
Oxidation of Hydroxyurea with Oxovanadium(V) Ions in Acidic Aqueous Solution // Journal of Inorganic Biochemistry, 100 (2006), 10; 1606-1613 doi:10.1016/j.jinorgbio.2006.05.008 (međunarodna recenzija, članak, znanstveni)
Gabričević, M., Bešić, E., Biruš, M., Zahl, A. & van Eldik, R. (2006) Oxidation of Hydroxyurea with Oxovanadium(V) Ions in Acidic Aqueous Solution. Journal of Inorganic Biochemistry, 100 (10), 1606-1613 doi:10.1016/j.jinorgbio.2006.05.008.
@article{article, year = {2006}, pages = {1606-1613}, DOI = {10.1016/j.jinorgbio.2006.05.008}, keywords = {Dioxovanaium(V), Hydroxyurea, Redox, Mechanism, EPR spectroscopy}, journal = {Journal of Inorganic Biochemistry}, doi = {10.1016/j.jinorgbio.2006.05.008}, volume = {100}, number = {10}, issn = {0162-0134}, title = {Oxidation of Hydroxyurea with Oxovanadium(V) Ions in Acidic Aqueous Solution}, keyword = {Dioxovanaium(V), Hydroxyurea, Redox, Mechanism, EPR spectroscopy} }

Časopis indeksira:


  • Current Contents Connect (CCC)
  • Web of Science Core Collection (WoSCC)
    • Science Citation Index Expanded (SCI-EXP)
    • SCI-EXP, SSCI i/ili A&HCI
  • Scopus
  • MEDLINE


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