Catalysis of the hydrolysis of phosphorus acids esters by the mixed micelles of long-chain amines and cetylpyridinium bromide

Mirgorodskaya, A. B.; Kudryavtseva, L. A.; Zuev, Yuri F.; Archipov, V. P.; Idiyatullin, Zyamil Sh.

doi:10.1070/mc1999v009n05abeh001127

Cited by 16 publications

(11 citation statements)

References 15 publications

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“…In the hydrolysis of 1 in the micellar CPB solutions, the ratio between the contributions from alkaline hydrolysis and hydrolysis catalysed by amines via the general-base mechanism, as well as the resulting micellar catalytic effect, depends on the hydrophobicity of the amines. 8 For the reaction in ME-1, the contribution from the general-base mechanism increases and becomes predominant with increasing amine concentration and decreasing pH (Figure 1); the influence of the hydrophobicity of the nucleophile is insignificant. Moreover, the high solubilising ability of ME-1 makes it possible to obtain systems with high amine concentrations.…”

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confidence: 99%

“…If the amines participate in the micelle formation or occur in micellar solutions of surfactants, the micellar catalytic effect leads to deviations from the Brönsted relation. 7,8 The kinetics of hydrolysis of 1 in ME-1 in the presence of primary amines was monitored spectroscopically under condi-tions of the pseudo-first-order reaction by measuring an increase in the absorbance due to the liberation of p-nitrophenolate (l = = 400 nm).…”

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confidence: 99%

“…Unlike micellar solutions, 8 the k obs = f(c am ) functions in CPBbased microemulsions are linear over a wide concentration range (up to 0.2 mol dm -3 ) for amines of various hydrophobicity (Figure 1). The second-order rate constants (k 2 ) averaged by volume are presented in Table 1.…”

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confidence: 99%

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Cetylpyridinium bromide-based microemulsions as media for the hydrolysis of phosphorus acids esters in the presence of primary amines

Mirgorodskaya

Kudryavtseva

Zuev

et al. 2000

Mendeleev Communications

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Cetylpyridinium bromide-based microemulsions as media for the hydrolysis of phosphorus acids esters in the presence of primary amines

Mirgorodskaya

Kudryavtseva

Zuev

et al. 2000

Mendeleev Communications

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“…Dependence of the observed rate constant for p nitro phenolat cleavage on the surfactant concentration in the pres ence(1)(2)(3)(4)(5) and in the absence (6) of amines (25 °C, pH 9.2) at C am = 0.0025 mol L -1 : 1 -Gem 16, decylamine, 2 -Gem 12, decylamine, 3 -CTAB, decylamine, 4 -Gem 16, octylamine, 5 -DdTAB, decylamine; at C am = 0.0074 mol L -1 : 4´ -Gem 16, octylamine.…”

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“…Dependence of the p nitrophenol pK а on the surfactant concentration: nonionic surfactant is Triton X 100 (1); ca tionic surfactants are DdTAB (2), CTAB (3), Gem 12 (4), and Gem 16(5).…”

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Mixed micellar systems of geminal alkylammonium surfactants and long-chain amines

et al. 2010

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Numerical characteristics of the aggregation behavior of geminal alkylammonium surfac tants in aqueous solutions (the size of micelles, the packing of surfactant molecules, the surface potential, the extent of counterion binding) were determined. The formation of mixed micelles geminal surfactant/decylamine resulted in substantial decrease in amine pK a ; this is the crucial factor determining the strong catalytic effect of the system in ester bond cleavage processes.The most important feature of aqueous micellar solu tions of surfactants is the capability of solubilization of reactive substances possessing different hydrophilic lipo philic properties; this substantially extends the possibility of their use as reaction media. 1-4 Transfer of the reactants from the bulk of solvent to the micellar pseudophase is accompanied by changes in their microenvironment, which in turn leads to changes in the reactivity, acid base properties, spectral, and other physicochemical parame ters. The most pronounced changes are observed for am phiphilic reagents (long chain aliphatic amines, alkylphe nols), 5-7 which can form mixed micelles with surfactants, containing functional groups sensitive to variation of pH values of the media and the component ratio.In the last decade, interest in the geminal (dimeric) surfactants and highly organized systems based on them increased sharply. Geminal surfactants contain two hy drophobic radicals and two head (usually, charged) groups linked by spacers with different rigidity. These compounds differ from their amphiphilic analogs containing only one head group and one hydrocarbon chain by lower values of the critical micelle concentration (CMC), high surface activity, and solubilizing action; they are also character ized by unusual morphological behavior. 8-11 A series of papers devoted to the study of the aggregation behaviour and the structural properties of geminal surfactants were published. 12-14 A number of studies 15-18 on the catalytic effect of micellar solutions of these compounds in the nucleophilic substitution reactions were reported.The present work is dedicated to elucidation of the possibility of using aqueous solutions of geminal cationic surfactants as media for reactions involving hydrophobic alkylamines. Taking n decylamine as an example, data on the solubilizing effect, aggregation properties, and cata lytic activity in ester bonds cleavage of two geminal alkyl ammonium surfactants with different length of hydropho bic fragments six methylene unit spacers [C 12 H 25 (CH 3 ) 2 N(CH 2 ) 6 N(CH 3 ) 2 C 12 H 25 ] 2+ •2Br -(Gem 12), [C 16 H 33 (CH 3 ) 2 N(CH 2 ) 6 N(CH 3 ) 2 C 16 H 33 ] 2+ •2Br - (Gem 16) were obtained.A comparative analysis of their properties and those of analogous monomeric cationic surfactants, dodecyltri methylammonium bromide (DdTAB) and cetyltrimethyl ammonium bromide (CTAB), was carried out. ExperimentalCommercially available CTAB and DdTAB (Sigma), n de cylamine, n octylamine, and also p nitrophenyl acetate (PNPA) (Fluka) with 99% purity were us...

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Structural Factors in Micellar Catalysis: NMR Self-Diffusion Study

Zuev

Idiyatullin

Fedotov

et al. 2002

Magnetic Resonance in Colloid and Interface Science

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Catalysis of the hydrolysis of phosphorus acids esters by the mixed micelles of long-chain amines and cetylpyridinium bromide

Cited by 16 publications

References 15 publications

Cetylpyridinium bromide-based microemulsions as media for the hydrolysis of phosphorus acids esters in the presence of primary amines

Cetylpyridinium bromide-based microemulsions as media for the hydrolysis of phosphorus acids esters in the presence of primary amines

Mixed micellar systems of geminal alkylammonium surfactants and long-chain amines

Structural Factors in Micellar Catalysis: NMR Self-Diffusion Study

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