Publication Type |
Journal Article |
Title |
A new binuclear oxovanadium(V) complex as a catalyst in combination with pyrazinecarboxylic acid (PCA) for efficient alkane oxygenation by H2O2 |
Authors |
Manas Sutradhar Nikita V. Shvydkiy M. Fátima C. Guedes da Silva M Kirillova Yuriy N. Kozlov Armando J.L. Pombeiro Georgiy B. Shul'pin |
Groups |
CCC BioMol |
Journal |
DALTON TRANSACTIONS |
Year |
2013 |
Month |
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Volume |
42 |
Number |
33 |
Pages |
11791-11803 |
Abstract |
A new binuclear oxovanadium(V) complex [\VO(OEt)(EtOH)\(2)L] (1) where H4L is bis(2-hydroxybenzylidene)terephthalohydrazide has been synthesized and fully characterized. The combination of 1 with pyrazine-2-carboxylic acid (PCA; a cocatalyst) affords a catalytic system for the efficient oxidation of saturated hydrocarbons, RH, with hydrogen peroxide and air in acetonitrile solution at 50 degrees C to produce alkyl hydroperoxides, ROOH, as the main primary products. Very high turnover numbers (TONs) have been attained in this reaction: for example, after 2220 min, TON = 44 000 and initial TOF (turnover frequency) = 3300 h(-1) per molecule of complex 1. The estimated activation energy of the cyclohexane oxygenation in the presence of 1/PCA is E-a = 16 +/- 2 kcal mol(-1). This value is identical to that obtained for the cyclohexane oxidation with H2O2 catalyzed by the (n-Bu4N)[VO3]/PCA combination (17 +/- 2 kcal mol(-1)). The dependences of initial oxidation rates W-0 on the initial concentrations of all components of the reaction mixture have been determined. Based on these kinetic data and on the regio- and bond-selectivity parameters measured in the oxidation of linear and branched alkanes a mechanism of the oxidation has been proposed which includes the generation of hydroxyl radicals in the crucial stage. |
DOI |
http://dx.doi.org/10.1039/c3dt50584g |
ISBN |
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Publisher |
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Book Title |
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ISSN |
1477-9226 |
EISSN |
1477-9234 |
Conference Name |
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Bibtex ID |
ISI:000322525100007 |
Observations |
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