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8707358 
Journal Article 
A Ruthenium(III) Analogue of the Udenfriend System: Ru(III)-EDTA-Ascorbate-Molecular Oxygen in the Effective Oxygen Atom Transfer Reaction of Saturated and Unsaturated Organic Compounds 
Taqui Khan, MM; Shukla, RS; Rao, AP 
1989 
Yes 
Inorganic Chemistry
ISSN: 0020-1669
EISSN: 1520-510X 
28 
3 
452-458 
English 
WOS:A1989T279600016 
The oxidation of cyclohexane, cyclohexanol, and cyclohexene by a ruthenium(III) analogue of the Udenfriend system, involving Ru(III)-EDTA-ascorbic acid and molecular oxygen, was investigated at 30 °C and μ= 0.1 M KNO3in a 50% (v/v) mixture of 1,4-dioxane and water in acidic medium. The kinetic parameters of the complicated oxidation reactions were determined by potentiometric, spectrophotometric, and manometric techniques. The rates of oxidation of the substrates are first order with respect to the Ru(III)-EDTA complex, ascorbic acid, and molecular oxygen concentrations and inverse first order with respect to the hydrogen ion concentration. A first-order dependence with respect to cyclohexene and cyclohexanol and a fractional-order dependence in cyclohexane concentration were observed. The oxidation of cyclohexane gives cyclohexanol, m-l,3-cyclohexanediol, and cyclohexanone whereas the oxidation of cyclohexene gives 100% of the epoxide. The hydroxylation of cyclohexanol gives exclusively cis-l,3-cyclohexanediol. The rate of oxidation of substrates with the Ru(III)-EDTA complex in the absence of ascorbic acid is slower than that of the Ru(III)-EDTA-ascorbate system. On the basis of kinetics and experimental results, the rate laws for all the oxidation reactions were derived and their mechanisms discussed. The order of the reactivity of the substrates is cyclohexane < cyclohexanol < cyclohexene. 1989, American Chemical Society. All rights reserved.