Solvatochromic parameters and linear solvation energy relationships for hydrolysis of hydroxamic acids

Abstract

Kinetic solvent effects on hydrolysis of hydroxamic acids of the type R.N (OH). C=O.R'[R=H; R'=CH₃, C₆H₅, C₆H₄-OH; R=CH₃-C₆H₄Rʹ = C₆H₅] in aqueous mixtures (10-70% <i>v/v) </i>of some polar protic, polar aprotic and low polarity basic

solvents have been studied. The solvatochromic parameters α for the hydrogen-bond-donating ability, β, for the hydrogen-bond- accepting ability and, π*, for the dipolarity/polarizability and linear solvation energy relationships have been used to quantify solvent effects. Kamlet and Taft's triparametric equation explain the greater than 70% of the effect of solvent on the hydrolysis. The other parameters i.e., D, E_T and Z have also been used.