A Study of the Kinetics and Mechanism of Oxidation of Fluorene by Alkaline Hexacyanoferrate(III)

Abstract

Kinetics of hexacyanoferrate (III) (HCF) oxidation of fluorene (Fl) in organic alkaline medium has been studied by spectrophotometric technique at a constant ionic strength of 0.15 mol dm -3 and at a temperature of 25°C. The reaction showed a first order kinetics with respect to [HCF] and fractional-first order dependences on both [Fl] and [OH -]. The oxidation rate was increased with the increase in the ionic strength of the reaction medium. The oxidation mechanism was suggested which involves formation of a 1:1 intermediate complex between fluorene and HCF species in a pre-equilibrium step. The final oxidation product of fluorene was identified by spectroscopic and chemical tools as 9H-fluorenone. The appropriate rate law expression was deduced and the reaction constants involved in the mechanism were evaluated. The activation parameters of the rate constant of the slow step along with the thermodynamic quantities of the equilibrium constants were evaluated and discussed.