Kinetic solvent effect on the hydrolysis of N-Benzylbenzohydroxamic acid in some binary aqueous solvent mixtures

Abstract

Abstract The rates of acidic hydrolysis of N-benzylbenzohydroxamic acid were measured over the temperature range 45–65°C in aqueous 1,4-dioxane, dimethylsulfoxide, N,N-dimethylformamide, tetrahydrofuran, sulfolane, acetone, and methanol of different composition [10–70% (v/v)]. The rate constant varies with the varying composition of solvent which is attributed to differential solvation of the transition state, solute solvent interactions, solvent structure, and dielectric behaviour of the medium. The solvatochromic parameters and linear solvation energy relationships ‘π” for the dipolarity/polarizability, ‘β’ for the hydrogen-bond accepting ability and ‘α’ for the hydrogen bond donating ability of solvent mixtures have been used through multiple regression of the rate constants. The activation parameters ΔH≠, ΔS≠, and ΔG≠ have also been evaluated.