Kinetic Study Regarding Molecularity, Bond?Fission and Reaction Mechanism In The Acid Hydrolysis of 5?Chloro, 2?Methyl Aniline Phosphate Triester

Kinetic study of the hydrolysis of 5chloro, 2methyl aniline triester has been done in 0.1 to 6.0 mol. dm-.3 HCl and pH 1.24 to 7.46 at 80 0.5oC in aqueous dioxan (v/v) mixture. The rate of hydrolysis was determined by measuring the rate of appearance of inorganic phosphates by Allens modified colorimetric method [1]. The concentration of triester in all kinetic runs was maintained at 5.0104 mol dm3. Conjugate acid and neutral species of the triester have been found to be reactive, but this discussion is based only on conjugate acid species. Effects of variable factors such as temperature, pH, ionic strength, concentrations etc. on the rate of hydrolysis of the triester have been studied in detail. Concepts such as Hammett acidity function [2], Bunnett parameters [3, 4], Zucker-Hammett hypothesis [5], isokinetic relationship [6] together with Arrhenius parameters [7] and comparative isokinetic data of other triesters of known mechanism were considered for deciding the molecularity, bond-fission and probable mechanism of the hydrolysis of the triester.