Aminolysis ofO-alkylO-4-nitropyenyl chloromethylphosphonates in reverse micellar solutions of the nonionic surfactant

The reaction ofn-hexylamine withO-alkylO-4-nitrophenyl chloromethylphosphonates in toluene solutions of poly(ethylene glycol)-600 monolaurate (PM) has been studied by spectrophotometry. The reverse micelles of the nonionic surfactant increase more than tenfold the observed rate constant of aminolysis. The catalytic activity of the surfactant is practically independent of the alkyl radical length of phosphonate. An increase in the concentration of amine results in a decrease in the catalytic efficiency. The character of the dependence of the rate constant on the concentration of PM is affected by the alkyl chain length of the substrate. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1735–1738, September, 1998.     

The influence of the structure of tetracoordinate phosphorus acid esters on the catalytic effect of the sodium dodecyl sulfate-hexanol-water ternary reverse micellar system

The catalytic effect of the sodium dodecyl sulfate-hexanol-water ternary reverse micellar system in the alkaline hydrolysis ofO-alkylO′-aryl chloromethylphosphonates as a function of the substrate structure was studied. The micellar effect is mainly determined by a change in the electronic properties of the substituents, while the hydrophobicity plays a secondary role. The kinetic data were examined in the framework of the pseudo-phase model of micellar catalysis. The rate constants of the reaction in the surface layer and the partition constants of the reactants were calculated. Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1366–1370., August, 2000.     

Alkylation reaction of amines by dimethyl phosphite

The alkylation reaction kinetics of a series of amines of different structures by dimethyl phosphite have been studied. Two-parameter correlation equations have been deduced, relating reactivity to steric and inductive effects of substituent s attached to the nitrogen atom in the amine; a Swain-Scott equation has also been deduced, establishing a correlation between the rate of alkylation and the nucleophilicity of the reaction site. When steric conditions at the nitrogen atom are fixed, as in the case of orthoaminomethylphenols, the reactivity follows a Brönsted equation.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1129–1133, May, 1990.     

Reaction of 2-alkylaminomethylphenols with 4-nitrophenyl-bis(chloromethyl)phosphinate in toluene micellar solutions of polyethylene glycol-600 monolaurate

The effect of polyethylene glycol-600 monolaurate (PEG-ML) reversed micelles on the reaction of 2-alkylaminomethylphenols (AMP) with 4-nitrophenyl-bis(chloromethyl) phosphinate in toluene has been investigated. PEG-ML increases the observed rate constant of the reaction by more than one order of magnitude. AMP concentration in solution affects the position of the maximum on the concentration dependence of the micellar-catalyzed-reaction rate constants. The reaction rate constant in the micellar phase and the binding constant of the substrate with micelles depend on the alkyl chain length and AMP concentration. Inhibition of the reaction studied is observed in the presence of high PEG-ML concentrations and low AMP concentrations.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2134–2138, December, 1994.     

Hydrolysis of bis(4-nitrophenyl) ethyl phosphate in micellar solutions of dicationic surfactants

The effect of dicationic surfactants on the hydrolysis of bis(4-nitrophenyl) ethyl phosphate in a borate buffer is studied. The presence of long-chain surfactants results in a significant (up to 50-fold) increase in the observed rate constant (k _obs) of the process. The catalytic effect of micelles increases with increasing alkyl chain length due to the strengthening of binding of the reagents by micelles. The presence of two cationic centers in the surfactant molecule enhances the catalytic properties of micelles. The dependence ofk _obs of hydrolysis of the substrate on the borate buffer concentration is studied. Alkaline hydrolysis is more sensitive to the added surfactant than the reaction involving borate ions.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1576–1580, September, 1994.     

Micellar effects of cation-active surfactants on the reaction of (o-aminomethyl)phenols with ethylp-nitrophenyl chloromethylphosphonate

The reaction of (o-aminomethyl)phenols with ethylp-nitrophenyl chloromethylphosphonate in aqueous micellar solutions of cation-active surfactants has been studied. The effect of the structure of the surfactant and the nucleophile, pH of the medium, and temperature on the reaction rate in the micellar phase has been investigated. The rate constants in micelles are much higher than those in water.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2065–2068, December, 1993.     

Micelle-Forming and Catalytic Properties of n-Alkyl(2-hydroxyethyl)dimethylammonium Bromides in the Phosphorylation of Tetrakis(dimethylaminomethyl)calixresorcin[4]arene

Micelle formation by n-alkyl(2-hydroxyethyl)dimethylammonium bromides in chloroform was studied by dielcometric titration and kinetic method. Increase in the length of the hydrocarbon chain leads to reduced critical micelle concentration. The region of structural reorganization of micelles was determined. n-Alkyl(2-hydroxyethyl)dimethylammonium bromides catalyze phosphorylation of tetrakis(dimethylamino- methyl)calixresorcin[4]arene. The catalytic activity of micelles depends on the hydrophobic properties and concentration of the surface-active substance, as well as on structural features of its aggregates.     

The inverted micellar catalysis of the reaction of 2-aminomethylphenols with 4-nitrophenyl bis(chloromethyl)phosphinate

The parameters of the reaction ofpara-substituted 2-aminomethylphenols with 4-nitrophenyl bis(chloromethyl)phosphinate in toluene catalyzed by reversed micelles of polyethylene glycol-600 monolaurate depend on the nucleophile structure. The efficiency of the catalytic action increases in the series of substitutes C₉H₁₉ ⁱ<H<Cl. An increase in the catalytic activity of micelles in the region of structural rearrangement of micelle aggregates was observed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 275–278, February, 1999.     

The reactivity of phosphonic esters in aqueous micellar solutions of cationic surfactants

The micellar effect of cationic surfactants in alkaline hydrolysis of O-alkyl-O-aryl-chloromethyl phosphonates involves a positive contribution of concentrating the reagents and a negative effect of the micellar environment due to a loss in the activation entropy. The reactivity of substrates in micelles depends on both electronic and hydrophobic characteristics of substituents in the aryl group.     

The Influence of the Structure of Phosphorus Acids Esters on their Reactivity in Aqueous and Nonaqueous Micellar Solutions

Abstract

The kinetics of the basic hydrolysis of O-alkyl-O-p-nitrophenyl-chloromethylphosphonate in aqueous micellar solutions of cetylpyridinium bromide (CPB) and the aminolysis of these substrates by n-hexylamine in the reverse micelles of polyethylene glycole-600-monolaurate (PM) in toluene has been studied.