The hydrolysis of Brilliant Green and some derivatives. Part 2. The kinetics of the hydrolysis of 3- and 4-substituted derivatives of Brilliant Green

Abstract

Rate constants have been measured for the reactions of hydroxide ion with the following derivatives of Brilliant Green in aqueous solution: 3-X (X = Cl, OMe, CF₃, Me, NO₂, NMe₂, or OH); 4-X (X = Cl, OMe, CF₃, Me, NO₂, or NMe₂). The substituents affect the rate of hydrolysis to an extent linearly related to the appropriate Hammett substituent constant. Thermodynamic parameters ΔH^‡ and ΔS^‡ have been obtained for each dye and the reaction is shown to be under entropy control.