ISSN:
1434-1948
Schlagwort(e):
Kinetics
;
Oxidations
;
Iron
;
Oxygen
;
High pressure
;
Chemistry
;
General Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
The complicated oxidation kinetics of the reaction of [FeII(cdta)] [cdta = 1,2-(N,N′- cyclohexanediamine)tetraacetate] with molecular oxygen was investigated as a function of [FeII], [O2], pH, temperature and pressure. In the presence of an excess of [FeII(cdta)] three steps could be observed, for which the following rate constants were found at 25°C; k1 = 1080 ± 16 M-1 s-1, k2 = 103 ± 4 M-1 s-1 and k3 = 59 ± 5 M-1 s-1. These reaction steps can be accounted for in terms of the following mechanism: (1) [FeII(cdta)H2O]2- reacts with O2 by a substitution process to form [FeII(cdta)O2]2-; (2) electron-transfer to form an FeIII-superoxo species; (3) subsequent bridge formation followed by electron-transfer to give [(cdta)FeIII-O22--FeIII(cdta)]4-; and (4) a fast decomposition of the peroxide intermediate yielding the monomeric [FeIII(cdta)] and H2O2. Rate and activation parameters for these steps are reported and discussed in terms of the postulated mechanism and in reference to available literature data.Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2005/1999/98232_s.pdf or from the author.
Zusätzliches Material:
6 Ill.
Materialart:
Digitale Medien
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