MOLECULAR CATALYSIS AND INTERACTIONS IN AQUEOUS SOLUTIONS

Results of an investigation of some of the mechanisms leading to the eventual hydrolysis of certain phosphonate esters are presented. Studies were concerned in general with nucleophilic exchange reactions involving these esters, and more particularly with the replacement reactions of isopropyl p-nitrophenyl methyl phosphonate 1370 and with the hydrolytic rates of certain other derivatives. Kinetic studies of hydrolysis of isopropyl o-hydroxyphenyl methyl phosphonate show that this compound hydrolyzes by three kinetically different mechanisms 1 water attack on the unionized molecule 2 hydrolysis of the ionized molecule by probable intramolecular catalysis and 3 hydroxyl attack on the innized molecule, with the subsequent formation of o-hydroxyphenyl methyl phosphonic acid and the elimination of the isopropyl group. Effects of various nuclear substituents on the rate of hydrolysis of the phenolate esters were also determined.