Nucleophilic Reactivity of Hydroxide and Hydroperoxide Ions in Aqueous-Alcoholic Media and of HCO 4 − Ion in Water

Abstract

Nucleophilic reactivity of hydroxide and hydroperoxide ions toward ethyl 4-nitrophenyl ethylphosphonate, diethyl 4-nitrophenyl phosphate, 4-nitrophenyl 4-toluenesulfonate, and 4-nitrophenyl dimethylcarbamate in the system H2O2-KOH was studied in aqueous-alcoholic solutions at 25°C. The rate of reactions of both anions with ethyl 4-nitrophenyl ethylphosphonate, diethyl 4-nitrophenyl phosphate, and 4-nitrophenyl dimethylcarbamate and of hydroxide ion with 4-nitrophenyl 4-toluenesulfonate increases with rise in the fraction of the alcohol in mixtures of water with isopropyl and tert-butyl alcohols, while the reaction rate of hydroperoxide ion with 4-nitrophenyl 4-toluenesulfonate decreases. The rate of reactions of both anions with all the above substrates in mixtures of water with ethylene glycol decreases as the fraction of the latter rises. The apparent rate of the reaction of ethyl 4-nitrophenyl ethylphosphonate with anionic nucleophiles in the system H2O2-HO−-HCO 3 − in water at pH 8.5 almost does not depend on the concentration of ammonium hydrogen carbonate up to a value of 1 M, and it increases when the NH4HCO3 concentration exceeds 1 M. Mixtures of water with the lower monohydric alcohols were recommended for use as components of H2O2-HO−-HCO 3 − systems for oxidative decomposition of ecotoxicants.