Hydrolysis is a chemical transformation process in which an organic molecule, RX, reacts with water, forming a new carbon-oxygen bond and cleaving a carbon-X bond in the original molecule. Hydrolysis is likely to be the most important reaction of organic compounds with water in aqueous environments and is a significant environmental fate process for many organic chemicals. Hydrolysis is a family of reactions involving compound types as diverse as alkyl halides, carboxylic acid esters, organophosphonates, carbamates, epoxides, and nitriles. When an organic compound undergoes hydrolysis, a nucleophile (water or hydroxide ion) attacks an electrophile (carbon atom, phosphorus atom, etc.) and displaces a leaving group (chloride, phenoxide, etc.). The hydrolysis of organic chemicals in water is first-order in the concentration of the organic species; the rate of disappearance of RX is directly proportional to the concentration of the compound. Experimental measurement of the rate of hydrolysis should involve the determination of the form of the rate law, the magnitude of the rate constants, the products of reaction, temperature dependence (energy of activation). The rate of hydrolysis of organic chemicals increases with temperature. The quantitative relationship between the rate constant and temperature is frequently expressed by the Arrhenius equation. Hydrolysis reactions, which frequently involve ionic species as reactants, intermediates, and/or products, are affected by changes in the solvating power of the reaction medium. Estimation methods for hydrolysis include the application of linear free energy relationships, estimation of rate constant for specific acid-catalyzed hydrolysis by the Hammett, or Taft correlations, estimation of the rate constant for neutral hydrolysis by the Hammett correlation, estimation of the rate constant for specific base-catalyzed hydrolysis by the Hammett or Taft correlations or correlation with the negative log of the acid dissociation constant of a leaving group. (See also W91-07767) (Geiger-PTT)
Lyman, WJ; Reehl, WF; Rosenblatt, DH