The influence of the hydroxylic solvents on the reaction rates of diazodiphenylmethane with cycloalkylcarboxylic and cycloalkenylcarboxylic acids

Abstract

The rate constants for the reaction of diazodiphenylmethane with cyclohexylcarboxylic, cyclopentylcarboxylic, cyclohex-3-enylcarboxylic and cyclopent-3-enylcarboxylic acids have been determined in ten alcohols at 30degreesC using the UV-spectroscopic method. In order to explain the kinetic results through solvent effects, the second order rate constants of the examined acids are correlated using the total solvatochromic equation, of the form: log k = A(0) sn* + aalpha + bbeta, where pi*, beta and alpha represent the solvent dipolarity/polarizability, solvent hydrogen bond acceptor basicities and hydrogen bond donor acidities, respectively. The correlation of the kinetic data were carried out by means of multiple linear regression analysis and solvent effects on the reaction rates have been analysed in terms of the initial state and the transition state contributions.