Kinetic investigations of the reaction of brilliant green with alkalies. Influence of permittivity and temperature

Abstract

The influence of permittivity and temperature on the rate of reaction of brilliant green with hydroxyl ions has been examined. The variation of rate with the permittivity is anomalous, and indicates the existence of strong specific solvent effect. Kinetic data at different temperatures at varying ionic strength and permittivity have been utilized for the determination of thermodynamic quantities of activation ΔS^≠, ΔG^≠ and ΔH^≠. These quantities obey the following equations quantitatively : ΔS_I^≠= 2.3R(1.53Z_AZ_B)√I; ΔH₁^≠= 2.3RT(0.52Z_AZ_B)√I. The frequency factor increased in an acetone+water medium; this reflects an increase in solvation. A comparison of the frequency factors obtained by the collision theory and Debye and Christiansen theory has been made. The mechanism of the reaction is in agreement with the kinetic data.