Mechanistic aspects of the reduction of ruthenium(III) catalyzed

Abstract

The kinetics of Ru I I I catalyzed reduction of hexacyanoferrate(III) [Fe(CN) 6 ] 3) , by atenolol in alkaline medium at constant ionic strength (0.80 mol dm )3 ) has been studied spectrophotometrically, using a rapid kinetic accessory. The reaction between atenolol and [Fe(CN) 6 ] 3) in alkaline medium exhibits 1:2 stoichiometry [atenolol:Fe(CN) 63) ]. The reaction showed first order kinetics in [Fe(CN) 6 ] 3) concentration and apparent less than unit order dependence, each in atenolol and alkali concentrations. Effect of added products, ionic strength and dielectric constant of the reaction medium have been investigated. A retarding effect was observed by one of the products i.e., hexacyanoferrate(II). The main products were identified by i.r., n.m.r., fluorimetric and mass spectral studies. A mechanism involving the formation of a complex between the atenolol and the hydroxylated species of ruthenium(III) has been proposed. The active species of oxidant and catalyst were [Fe(CN) 6 ] 3) and [Ru (H 2 O) 5 OH] 2+ , respectively. The reaction constants involved in the mechanism were evaluated. The activation parameters were computed with respect to the slow step of the mechanism, and discussed.

Mechanistic studies of uncatalyzed and ruthenium(III)-catalyzed oxidation of the antibiotic drug chloramphenicol by hexacyanoferrate(III) in aqueous alkaline medium: a comparative kinetic study

“…On the basis of the experimental results, a mechanism can be proposed for which all the observed orders in each constituent, i.e., [oxidant], [reductant], catalyst, and [OH − ], may be well accounted for. Oxidation of chloramphenicol by HCF(III) in NaOH media is a non-complementary reaction [18]. …”