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We have studied the effect of different surfactants on the rate of diethyl sulfide (Et 2 S) oxidation by hydrogen peroxide and peroxymonocarbonate in aqueous solutions. In all the studied cases, the rate of the reaction between Et 2 S and H 2 O 2 decreases as the surfactant concentration increases. The reaction of Et 2 S with HCO 4 − is catalyzed by cationic surfactants and inhibited by neutral and anionic surfactants.A very important endeavor is the search for new systems for rapid oxidation of organic sulfides, which are active components of toxic agents. This task involves solving two fundamental problems: replacing the toxic and aggressive derivatives of hypochlorous acid widely used for disposal of sulfides [1], and selecting solvents that on the one hand make it possible to considerably increase the solubility of toxic sulfides (often practically insoluble in water) and on the other hand to preserve their fast oxidation rate.One promising route to solving the first problem is activation of hydrogen peroxide with formation of peroxy acids, which have high activity in oxidation of sulfides. Bicarbonates [2], silicates [3], nitrites [4], molybdates [5, 6], phthalates [7], and other compounds can be used as the H 2 O 2 activators. Water-alcohol mixtures are used to improve the solubility of the sulfides [2].Recently [8] we studied the bicarbonate-catalyzed oxidation of diethyl sulfide (Et 2 S), modeling 2,2-dichloroethyl sulfide (mustard gas), by hydrogen peroxide in water and in aqueous alcoholic media of variable composition. We established that at pH 7-9, the reaction includes intermediate formation of peroxymonocarbonate:(1)The value of the equilibrium constant for peroxymonocarbonate formation (K (1) ≈ 27) is the same for aqueous and aqueous alcoholic media [2,8]. The rate constant for the reaction (k (2) ) is about 100 times higher than the corresponding value for oxidation of Et 2 S by hydrogen peroxide. In aqueous alcoholic media, the rates of both the catalytic route (with HCO 4 − ) andthe noncatalytic route (with H 2 O 2 ) are slowed down with an increase in the alcohol concentration and in the order HOC 2 H 4 OH > i-PrOH > t-BuOH, but the ratio of the rates is preserved.

The micellar effects of 1-cetyl-2-methyl-3-(2-hydroxyiminopropyl)imidazolium and 1-cetyl-3-hydroxyiminomethylpyridinium halides in acyl transfer reactions (phosphoryl, phosphonyl, and toluenesulfonyl) were investigated. Variation of the nature of the head group does not lead to change in the reactivity of the oximate group, while the nucleophilicity follows the basicity of the functional fragment. The increase of the observed reaction rates during transfer of the disintegration of the substrates from water to the micellar pseudophase is due both to concentration of the reagents and to change in the reactivity of the oximate group. The new detergent 1-cetyl-2-methyl-3-(2-hydroxyiminopropyl)imidazolium chloride is one of the most effective functional surfactants in the decomposition of organophosphorus compounds. Key words: functional surfactants based on pyridine and imidazole, nucleophilicity, micellar effects.Functional surfactants containing an a-nucleophilic fragment in the head group are usually characterized both by high nucleophilic reactivity and by effective solubilization of electrically neutral polar substrates, including excotoxicants of organophosphorus type [1-10]. During the design of new functional detergents an important role is played by the true solubility of the surfactant in water, the basicity of the functional group, and its reactivity. However, the introduction of the functional fragment often leads to a decrease in the solubility of the surfactant in water [1,2,5,8]. Therefore, during study of the micellar effects of such detergents, as during their use in systems for the decomposition of excotoxicants, it is necessary to introduce an inert surfactant -a co-detergent, and this makes the system multicomponent and less attractive from the practical standpoint. The nucleophilicity of functional detergents can be predicted on the basis of the reactivity of analogs not forming micelles [1,2,[7][8][9][10]. This opens up the possibility of specific modification of the structure of the surfactant with the aim of producing compounds with the required level of nucleophilicity. This is the approach that we used during the creation of functional detergents based on imidazole [7][8][9]. With variation of the position of the oximate group in the series of hydroxyiminomethyl-1-cetylpyridinium halides the variation of the observed rates of decomposition of 4-nitrophenyl diethyl phosphate corresponds likewise to the variation of the basicity of the a-nucleophilic fragment in hydroxyimino-1-methylpyridinium halides [1]. It is important to note that for oximes that are not micelle-forming compounds there is a single Brönsted relationship onto which the points for oximes containing both an imidazole ring and a pyridinium ring fit [11]. In so far as analysis of the experimental results in [1] in terms of the existing models for description of micellar effects was not made 0040-5760/08/4402-0093

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