Theoretical and Experimental Chemistry, Vol. 47, No. 6, January, 2012 (Russian Original Vol. 47, No. 6, November-December, 2011) CLEAVABLE DICATIONIC SURFACTANT MICELLAR SYSTEM FOR THE DECOMPOSITION OF ORGANOPHOSPHORUS COMPOUNDS UDC 541.183:541.127:541.128 T. M. Zubareva, A. V. Anikeev, E. A. Karpichev, A. N. Red’ko, T. M. Prokop’eva, and A. F. Popov A dimeric (gemini) surfactant containing cleavable ester groups has been synthesized and studied. The new surfactant has a low critical micelle concentration (2.7·10 –5 mol/L) and Krafft temperature (£0 °C). Alkaline hydrolysis of 4-nitrophenyl diethyl phosphonate and 4-nitrophenyl diethyl phosphate in the presence of micelles of gemini surfactant I proceeds 30-144 times more rapidly than in water. Chemical cleavage of gemini surfactant I in an alkaline medium is achieved in 96 h. Key words: dimeric (gemini) surfactants, cleavable surfactant, organophosphorus compounds (OPC), alkaline hydrolysis, micellar catalysis. Gemini surfactants have attracted considerable attention during the past two decades. Gemini surfactant molecules consist of two hydrophobic fragments and two polar head groups connected by a bridge termed a spacer. Such surfactants have a number of unique properties including anomalously low critical micelle concentration (CMC), high surface activity, and good solubilizing properties [1, 2]. This set of physicochemical properties is undoubtedly reflected in the course of chemical reactions in organized molecular systems. Solutions of gemini surfactants, which meet the requirements of “green chemistry,” may serve as a basis of recipes for the decomposition of organophosphorus compounds (OPC) [3]. Despite numerous studies on the aggregational behavior and structural features of gemini surfactants [2], there has been much less work on the effect of such micelles on the rate of chemical reactions [4, 5]. Furthermore, in order to solve practical problems, special attention has been given to the preparation of surfactants containing chemical bonds, whose dissociation can be effected under given conditions [6, 7]. The mechanisms for the decomposition of such bonds can differ, entailing either alkaline or acid hydrolysis, the action of ultraviolet light, or thermal decomposition. A common property of cleavable surfactants lies in their stability under given conditions such as neutral pH along with their capacity to undergo dissociation upon a change in conditions. As a rule, the chemical bond cleaved is located between the polar head group of the molecule and the nonpolar tail. The major problem in the design of such surfactants is enhancing their biodegradability, which is directly related to ecological safety and reducing technological stress on the environment [7, 8]. In a search for efficient systems for the decomposition of ecotoxicants, we have already synthesized and studied gemini surfactants containing ester and hydroxyl groups in the bridge unit, which permits us to achieve high rates of decomposition of esters of phosphorus acids by the hydroxide ion using low surfactant concentrations without codetergents [5]. However, these compounds did not contain chemical bonds, which could undergo chemical or biological decomposition under relatively mild conditions. 0040-5760/12/4706-0377 ©2012 Springer Science+Business Media, Inc. 377 ___________________________________________________________________________________________________ L. M. Litvinenko Institute of Physical Organic Chemistry and Coal Chemistry, National Academy of Sciences of Ukraine, Vul. R. Luxemburg, 70, Donets’k 83114, Ukraine. E-mail: ekarpichev@gmail.com. Translated from Teoreticheskaya i Éksperimental’naya Khimiya, Vol. 47, No. 6, pp. 363-369, November-December, 2011. Original article submitted November 14, 2011.