Oxidation of hydrates of cyclic ketones by alkaline hexacyanoferrate(III)

The kinetics of the reaction between cyclopentanone and cyclohexanone with hexacyanoferrate(III) ion in alkaline medium has been investigated at five temperatures. The data show that the reactions are quite fast and follow second order kinetics with respect to hydroxide ion concentrations while the rate follows direct proportionality with respect to the concentrations of hexacyanoferrate(III) ion and cyclic ketones. Rate of the reaction is not affected by the external addition of hexacyanoferrate(II) concentrations. Overall rate of the reaction may be given by−d[Fe(CN)63−]dt=kK1K2[S][OH−]2[Fe(CN)63−][H2O]2.

Graphical abstractOxidation of cyclopentanone and cyclohexanone by alkaline hexacyanoferrate(III) is quite fast. Second order in [OH−] indicates that oxidation proceeds through the formation of hydrates. Rate constant and thermodynamic parameters at five temperatures were calculated. Dicarboxylic acid was confirmed by IR as the product. Rate law given was .Figure optionsDownload full-size imageDownload as PowerPoint slide