Dodecanesulfonate

Sodium 1-dodecanesulfonate [2386-53-0] M 272.4. Twice recrystd from EtOH. 

FIG. 24 ct-c Isotherms at 22°C for purified alkanesulfonates. The curve is fitted by the Frumkin isotherm. , Sodium n-decanesulfonate x, sodium /i-dodecanesulfonate. 

FIG. 28 Dependence of the interface dilatation modulus e on the concentration c of homologous alkanesuifonates and decylbenzenesulfonate according to Ref. 48. O, Sodium tetradecanesulfonate x, sodium decylbenzenesulfonate , sodium dodecanesulfonate A, sodium decanesulfonate). 

Sodium dodecyl sulfate was separated from sodium dodecylbenzenesulfonate and sodium dodecanesulfonate by TLC on activated silica gel G. The spots were located by charring at 250°C for 15 min [281,282]. 

Figure 1. Plot of yield versus time for the aldol reactions in the presence of the dodecanesulfonate salts...

RP-HPLC determination of trace impurities of the toxic 4-aminopyridine in the central system-stimulating drug 3,4-diaminopyridine can be performed on condition that the impurity has a lower retention time. This was accomplished on applying ion pairing with dodecanesulfonate to maximize selectivity LOD 50 ppm of the impurity in the drug154. 

Increased retention of the analytes can also be achieved by addition of various ion-pair reagents in the mobile phase Tetrabutylammonium cations have typically been used as counter ions, at around pH 6.5, to increase retention and improve the selectivity in the analysis of monobasic penicillins (105, 123). Alkyl-sulfonic acids have been also used to improve the separation of -lactams bearing an amine function in their side chain or having a neutral side chain. Heptanesul-fonic acid (80, 103), decanesulfonic acid (87, 93, 106), dodecanesulfonic acid (77, 107-110), or mixtures of octanesulfonic and dodecanesulfonic acids (73, 75, 78, 79) constitute the principal alkylsulfonic acids used in -lactam analysis. In some applications, heptafluorobutyric acid (74, 76) or sodium thiosulfate (90, 112, 115, 116, 121, 122) has also been used as an ion-pairing reagent. 

Alternatively, ionic compounds can be recovered from solution on hydrophobic sorbents using ion-pair SPE (IP-SPE). Carson [121] notes that advantages of IP-SPE over ion-suppression RP-SPE or ion-exchange SPE include selectivity, compatibility with aqueous samples and rapid evaporative concentration of eluents, and potential application to multiclass multiresidue analysis. IP reagents (e.g., 1-dodecanesulfonic acid for pairing with basic analytes or tetrabutylammonium hydrogen sulfate for pairing with... 

Benzene may be oxidised to phenol in an ionic liquid-aqueous biphasic system employing dodecanesulfonate salts of Fe3+, Fe2+, Cu2+, Co2+ and Ni2+ as catalyst and hydrogen peroxide as oxidant.[85] Ionic liquids with long alkyl chains like [C8Ciim][PF6] form one phase with benzene and at the same time dissolve the catalyst. As the phenol product is preferably soluble in the aqueous phase product isolation was facile. Yet, reaction rates were only moderate and after six hours at 50°C conversion of benzene was in the range of 35-55%. 

FIGURE 7.7. Cyclic voltanunograms of the transfer of dodecanesulfonate ions at 0.5 mmol dm in W in the absence (solid line) and in the presence (dotted line) of sorbitan monooleate. Scan rate 50 mV s . The location of the mid-point potential is shown as the thick vertical line. Arrows a, b, c and d indicates the potentials stepped in chronoamperometric measurements (Figure 7.8). 

FIGURE 7.8. Potential-step chronoamperometty measurements for the transfer of dodecanesulfonate ions at four different potentials stepped from 500 mV to 350 (a), 250 (b), 175 (c) and 150 (d) mV. Other conditions are the same as those in Figure 7.7. Adapted from Figure 7.6 in Ref. [14]. 

For sodium dodecanesulfonate, a classical IPR for positively charged analytes, the potential determining ion is dodecanesulfonate, while the counter ion is the sodium cation. The electrified interphase will carry a barely negative charge since... 

Because the micellar interior is far from being rigid, a solubilized substrate is relatively mobile. Like micelle formation, solubilization is a dynamic equilibrium process. Representative recent examples are the solubilization of benzene, naphthalene, anthracene, and pyrene in aqueous solution by the addition of 1-dodecanesulfonic acid [391], the solubilization of fullerene Ceo in aqueous solutions of the non-ionic surfactant Triton X-100 [392], and the solubilization of a cholesteryl-group bearing pullulane (a hydrophobized polysaccharide) [393]. 

More energetic oxidation of thiols leads to sulfonic acids, Thiophenol dissolved in a solution of potassium hydroxide in dimethylformamide is oxidized by oxygen at 23.5 °C over a 22-h period to benzenesulfonic acid in 91% yield [53], Lauryl mercaptan gives dodecanesulfonic acid in 100% isolated yield upon treatment with potassium peroxymonosulfate, 2KHS05 KHS04 K2S04, at room temperature for 30 min [205]. 

Sinou and co-workers [73] studied the influence of different surfactants on the palladium-catalyzed asymmetric alkylation of l,3-diphenyl-2-propenyl acetate with dimethyl malonate in presence of potassium carbonate as base and non-water-soluble chiral ligands. Best results in activity and enatioselectivity (> 90% ee) were observed with 2,2 -bis(diphenylphosphino)-l,l -binaphthyl (BINAP) as ligand and cetyltrimethylammonium hydrogen sulfate as surfactant in aqueous medium. Water-stable Lewis acids as catalysts for aldol reactions were developed by Kobayashi and co-workers [74]. An acceleration of the reaction was indicated in presence of SDS as anionic surfactants. An additional promotion could be observed by combination of Lewis acid and surfactant (LASCs = Lewis acid-surfactant-combined catalysts) as shown in Eq. (3). Surfactant the anion of dodecanesulfonic acid. 

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