Kinetics of Cleavage of Paraoxon and Parathion by Cetyltrimethylammonium Iodosobenzoate

Abstract

Micellar cetyltrimethylammonium iodosobenzoate, (CTA)IBA, is highly reactive toward paraoxon (1) and parathion (2). In aqueous solution at pH 9, excess (CTA)IBA mediates their hydrolyses with kobs(max) ) 0.014 and 0.0030 s -1 , respectively, corresponding to half-lives of 50 s and 3.8 min. Comparisons with other phosphorolytic reagents suggest that (CTA)IBA merits serious consideration for the remediation of paraoxon or parathion contamination.

Nucleophilicity of functional surface active substances in the transfer of phosphoryl groups

“…From the preceding results it follows that the supernucleophilicity of surfactant IV is not only unsurpassed insensitivity, but it also exceeds known systems based on imidazolium [3][4][5][6], pyridylium [12,13], iodobenzoates [14], and other surfactants. The conclusion that the order of reactivity in the series of functional surfactants is retained on modifying the nucleophilic fragment was confirmed from data cited in the literature [12][13][14]. One of the clearest examples is the reactivity of surfactants containing the pyridine ring and the oxime unit (V-VII) with respect to NPDEP [12].…”

Enhanced nucleophilic reactivity of hydroxamate ions in some novel micellar systems for the cleavage of Parathion

“…In aqueous solution at pH 9.0, excess (CTA/IBA) mediates hydrolysis of parathion with k obs (max) 0.003 s −1 with half-life 3.8 min. Similarly cationic micelles of cetyltrimethylammonium bromide accelerate the reaction of OH − with parathion [20].…”

“…According to Buncel et al [18] the electrostatic attraction of cationic head groups of the surfactant at the micelle surface to the nucleophilic anion counterions lead to augmentation of the local concentration of nucleophile, while incorporation of the substrate in the micelle leads to higher local concentration of substrate, which accounts for higher reaction rate. Moss et al [19,20] studied kinetics of cleavage of parathion by the functional iodosobenzoate {(CTA)IBA}. In aqueous solution at pH 9.0, excess (CTA/IBA) mediates hydrolysis of parathion with k obs (max) 0.003 s −1 with half-life 3.8 min.…”

Preparation of cationic latexes with different length alkyl groups on their quaternary ammonium ions and their use as supports for IBA catalyst in the hydrolysis of PNPDPP

“…It is well established that this valance tautomeric form (2) is the dominant form in basic conditions [9]. After the discovery of the remarkable catalytic efficiency of IBA, the catalytic activities of it and various iodosyl compounds in micellar media and microemulsions have been investigated for the hydrolysis of various organophosphate esters at slightly basic conditions [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. In addition, polymer, silica, and titanium attached IBAs have been prepared as solid decontaminants and used for the same purpose [25][26][27][28].…”

“…Micelles function as the solubilizing medium for organophosphate esters as well as the binding site for IBA. This group intensively investigated IBA mediated hydrolysis of various organophosphate esters especially in the micellar medium of hexadecyltrimethylammonium chloride (CTACl) [9][10][11][12][13][14][15][16][17][18]. The hydrolysis reaction occurs via a nucleophilic attack and the tautomer of 1, namely 1-hydroxy-1,2-benziodoxolin-3-one (2), acts as the superior nucleophile in micellar medium.…”