Tetradecyltrimethylammonium ions

Patil et al. fabricated PVC electrodes sensitive to dodecyltri-methylammonium ions (DTA" ) and tetradecyltrimethylammonium ions (TTA" ). The electrode was used for determination of critical micelle concentration of TTAB in water. Moreover the electrode was tested in the presence of nonaqueous polar solvents, i.e., dimethylformamide (DMF) and dimethylsulphoxide (DMSO). 

Other cationic surfactants such as TTAB, DTAB, DODAB, STAC, CEDAB, and DDDAB have been used in CL reactions with less frequency. Thus, tetradecyltrimethylammonium bromide [TTAB] has been used to increase the sensitivity of the method to determine Fe(II) and total Fe based on the catalytic action of Fe(II) in the oxidation of luminol with hydrogen peroxide in an alkaline medium [47], While other surfactants such as HTAB, hexadecylpiridinium bromide (HPB), Brij-35, and SDS do not enhance the CL intensity, TTAB shows a maximum enhancement at a concentration of 2.7 X 10 2 M (Fig. 11). At the same time it was found that the catalytic effect of Fe(II) is extremely efficient in the presence of citric acid. With regard to the mechanism of the reaction, it is thought that Fe(II) forms an anionic complex with citric acid, being later concentrated on the surface of the TTAB cationic micelle. The complex reacts with the hydrogen peroxide to form hydroxy radical or superoxide ion on the... 

It has been shown that the addition of a small amount of the anionic surfactant sodium dodecyl sulfate (SDS) to a microemulsion based on nonionic surfactant increased the rate of decyl sulfonate formation from decyl bromide and sodium sulfite (Scheme 1 of Fig. 2) [59,60]. Addition of minor amounts of the cationic surfactant tetradecyltrimethylammonium gave either a rate increase or a rate decrease depending on the surfactant counterion. A poorly polarizable counterion, such as acetate, accelerated the reaction. A large, polarizable counterion, such as bromide, on the other hand, gave a slight decrease in reaction rate. The reaction profiles for the different systems are shown in Fig. 12. More recent studies indicate that when chloride is used as surfactant counterion the reaction may at least partly proceed in two steps, first chloride substitutes bromide to give decyl chloride, which reacts with the sulfite ion to give the final product [61]. 

An example of exchange with an oxygen-containing functional group is given which utilises a micellar system. Cationic micelles of cetyltrimethylammonium chloride and bromide, and tetradecyltrimethylammonium chloride and bromide, accelerate the reaction of 2-(4-nitro-phenoxy)quinoxaline with hydroxide ion to give quinoxalin-2(l/f)-one. ... 

Fig. 8 The effect of the addition of the cationic surfactant tetradecyltrimethylammonium bromide (TTAB) in the separation buffer for the separation of ion complexes with the chelating agent EDTA. TTAB, 0.5 mM, was added to the separation buffer for the separation of N03 (1), Cu-EDTA, Pb-EDTA, EDTA (2), Cr-EDTA (3), and Fe-EDTA (4). (For details of experimental conditions, see Ref. 341.)...

Ion pairing Ionic surfactants (< critical micelle concentration) Cetyltrimethylammonium bromide, tetradecyltrimethylammonium bromide Polyvalent metal cations (Ca " ", Al-, etc.) CHES and other alkanesulfonic acids, perchlorate... 

TTAOH, tetradecyltrimethylammonium hydroxide ESI-IT-MS, electrospray ionization ion trap mass spectrometry SB- -CD, sulfobutylether-p-cyclodextrin PHWE, pressurized hot water extraction FPD, flame photometric detector SPE, solid-phase extraction MES, 2-[morphine]ethanesulphonic acid DDAOH, didodecyldimethylammonium hydroxide. 

Lopez-Leon T, Santander-Ortega MJ, Ortega-Vinuesa JL, Bastos-Gonzalez D (2008) Hofmeister effects in colloidal systems influence of the surface namre. J Phys Chem C 112 16060-16069 Lyklema J (2009) Simple Hofmeister series. Chem Phys Lett 467 217-222 Maiti K, Mitra D, Guha S, Moulik AP (2009) Salt effect on self-aggregation of sodium dodecylsulfate (SDS) and tetradecyltrimethylammonium bromide (TTAB) physicochemical correlations and assessment in the light of Hofmeister (lyotropic) effect. J Mol Liq 146 44-51 Marcus Y (1997) Ion properties. Dekker, New York... 

As pointed out above, fused silica used as a material for separation columns in capillary electrophoretic methods has normally a negative charge. Various ions, especially surfactants or big amphoteric ions, can be, however, adsorbed on the surface, which dramatically influences the zeta potential. For example, the addition of a small concentration of a suitable cationic surfactant like tetradecyltrimethylammonium bromide to the BGE causes its adsorption at the inner capillary wall and the reversal of the EOF in silica capillaries to the anodic side. Such surfactants are... 

An example of the last effect is the hydroxide-ion catalysed photochemical Nef reaction of (4-nitrophenyl)nitromethane. This requires a prior deprotonation to give (126), which reacts to form 4-nitrobenzaldehyde presumably via (127). In this case it is a favourable ground-state pre-equilibrium which leads to catalysis by cationic micelles. By contrast, the quantum yield for alkaline hydrolysis of 3,4-dinitroanisole is decreased in tetradecyltrimethylammonium chloride micelles, simply because the lifetime of the triplet excited state is greatly reduced in micelles, and this is the species which is reactive towards hydroxide ion (Scheme 7). 

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