Synergistic effect of Ni(ii ) and Co(ii ) ions on the sulfite induced autoxidation of Cu(ii )/tetraglycine complex
| Autor: | María V. Alipázaga, Nina Coichev, Ruben G. M. Moreno |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Autoxidation
Cations Divalent Induction period Inorganic chemistry chemistry.chemical_element Cobalt Catalysis Oxygen Inorganic Chemistry Metal chemistry.chemical_compound Nickel chemistry Sulfite Oxidation state Ionic strength visual_art visual_art.visual_art_medium Sulfites Oligopeptides Oxidation-Reduction |
| Zdroj: | Dalton Trans.. :2036-2040 |
| ISSN: | 1477-9234 1477-9226 |
| DOI: | 10.1039/b404047c |
| Popis: | The synergistic effect of Ni(II) and Co(II) on the sulfite induced autoxidation of Cu(II)/tetraglycine was investigated spectrophotometrically at 25.0 degrees C, pH = 9.0, 1 x 10(-5) mol dm(-3)or = [S(IV)]or = 8 x 10(-5) mol dm(-3), [Cu(II)]= 1 x 10(-3) mol dm(-3), 1 x 10(-6) mol dm(-3)or = [Ni(II)] or [Co(II)]or = 1 x 10(-4) mol dm(-3), [O2] approximately 2.5 x 10(-4) mol dm(-3), and 0.1 mol dm(-3) ionic strength. In the absence of added nickel(II) or cobalt(II), the kinetic traces of Cu(III)G4 formation show a large induction period (about 3 h). The addition of trace amounts of Ni(II) or Co(II) increases the reaction rate significantly and the induction period drastically decreases (less than 0.5 s). The effectiveness of Cu(III)G4 formation becomes much higher. The metal ion in the trivalent oxidation state rapidly oxidizes SO3(2-) to SO3*-, which reacts with oxygen to produce SO5*-. The strongly generated oxidants oxidize Cu(II)G4 to Cu(III). |
| Databáze: | OpenAIRE |
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