Progrès de la recherche en sciences appliquées Libre accès

Abstrait

Kinetics and mechanism of ruthenium(III) catalyzed oxidation of d-glucose by 12-tungstocobaltate(III) in aqueous hydrochloric acid medium

Babasaheb D. Bhosale and Gavisiddappa S. Gokavi

The oxidation of D-Glucose by 12-tungstocobaltate(III) catalysed by Ruthenium(III) proceeds with transfer of an electron from catalyst to 12-tungstocobaltate(III) generating Ru(IV), which reacts with D-Glucose with the formation of a free radical. The free radical rapidly reacts with second molecule of oxidant to give arabinose. Increase in H+ ion concentration decreases the rate of reaction, due to acid catalysed enolisation. Decrease in dielectric constant and increase in ionic strength of medium, increases the rate of reaction. Slight decrease in rate is observed by increasing chloride ion concentration, due to conversion of active catalytic species RuCl5(H2O)2- into inactive higher chloro-complex, RuCl6 3-. The activation parameters were also determined which supports the outersphere nature of transition state between catalyst and oxidant