Tetraethylammonium ions

Compare electrostatic potential maps for tetrabenzyl-ammonium ion and tetraethylammonium ion with that of benzyltrimethylammonium ion. Are they likely to be as effective or more effective as phase-transfer catalysts as benzyltrimethylammonium ion Explain. (Hint Predict solubility properties for the three ions.)... 

FIGURE 32.4 Potential dependence of the interfacial tension J and the capacity C for the interface between solutions of 5mM tetrabutylammonium tetraphenylborate in 1,2-dichloroethane and lOOmM LiCl in water. The potential scale E represents the Galvani potential difference relative to the standard ion transfer potential for tetraethylammonium ion, cP o EA+ = 0.02 V. 

TABLE 1 Tetra-alkylammonium Ion, R4N, Transferred from W to DCE by the Coupling with the Redox Reaction Between NADH in W and a Quinone Derivative in DCE. Results After Shaking W Containing 10 M NADH and 10 M (R4N )2 SO4 with DCE Containing 10 M Quinone [Q Chloranil (CQ) or Toluquinone (TQ)] for 1 h. TPenA, TBA, and TEA Denote Tetrapentylammonium, Tetrabutylammonium, and Tetraethylammonium ions. Respectively... 

When Cs in Eq. (1) was replaced by tetramethylammonium ion, TMA, the positive limit of the amplitude shifted to more negative potentials and the amplitude decreased to be 0.28 V as compared to 0.40 V with Cs. Employing tetraethylammonium ion, TEA, instead of Cs+, the oscillation was not observed regardless of the magnitude of the applied current and the concentration of TEA+TPhB or TPA" TPhB . 

Remarkable data on primary hydration shells are obtained in non-aqueous solvents containing a definite amount of water. Thus, nitrobenzene saturated with water contains about 0.2 m H20. Because of much higher dipole moment of water than of nitrobenzene, the ions will be preferentially solvated by water. Under these conditions the following values of hydration numbers were obtained Li+ 6.5, H+ 5.5, Ag+ 4.4, Na+ 3.9, K+ 1.5, Tl+ 1.0, Rb+ 0.8, Cs+0.5, tetraethylammonium ion 0.0, CIO4 0.4, NO3 1.4 and tetraphenylborate anion 0.0 (assumption). 

Armstrong, C.M. (1971) Interaction of tetraethylammonium ion derivatives with the potassium channels of giant axons. The Journal of General Physiology, 58, 413-437. 

Weingart R The permeability to tetraethylammonium ions of the surface membrane and the intercalated disks of sheep and calf myocardium. J Physiol (Lond) 1974 240 741-762. 

The compound damages the pars recta portion of the proximal tubule with the loss of the brush border. The result is renal failure detected as glycosuria, proteinuria, loss of concentrating ability, and reduction in the clearance of inulin, p-aminohippuric acid, and tetraethylammonium ion. 

Effect of cations other than TPA has also been studied and the results are given in Table 2 and Fig.3. The molar ratio of additional cation/CTA" was kept at 1.4. It can be seen that cations like tetramethylammonium or tetraethylammonium ions or even sodium also gives highly ordered MCM-41 structure The BET surface area of these samples was found to be >1000 m2/g. Fig.3 shows that the MCM-41 structures obtained with these additional cations have improved hydrothermal stability. The long range ordering was unaffected by 4 days of hydrothermal treatment. Moreover, the surface area and pore volume of the water-treated samples was only marginally lower than that of the calcined samples. 

An interesting compound (205), isolated in ca. 15% yield, is obtained from the electrochemical oxidation of indole in acetonitrile using tetraethylammonium perchlorate as an electrolyte (78MI30503). Although it is obvious that the 3-substituent arises from the tetraethylammonium ion, no mechanism for the reaction is immediately apparent. 

Tetrahedron 6 represents one of the rare examples of supramolecular assemblies where complete enantiomeric resolution can be achieved. Treatment of racemic 6 with the chiral auxiliary (S) - N-melhylnicolinium (s-nic, 38) preferentially precipitates the diastereomeric ion-pair of (AAAA)-638. Once resolved, the chiral auxiliary can be replaced by achiral counter-ions such as tetramethyl- or tetraethylammonium ions, while the tetrahedra maintain their enantiopurity for at least 8 months, even upon extended heating in D2O (Fig. 24) [119]. 

Figure 11.9. Isothenns for polar and non-polar molecules on alkylammomum-exchanged montmoril-lonite (from BaiTer and Reay, 1957). UT, untreated TM, tetramethylammomum ion treatment TE, tetraethylammonium ion treatment.

The current oscillation observed by applying wi-W2 = —0.48 V was inhibited when tetraethylammonium ion, TEA+ or glutamate was added to W1 to be more than 10- M. 

The passive flux of sodium ions was shown to be highly correlated (r = 0.98) to the inverse of the skin s impedance [16]. Note that since this impedance was measured at 0.2 Hz, it represents mainly the skin s electrical resistance. A weaker correlation was obtained for the passive flux of tritiated water [19]. This was found to be true both before and after the application of iontophoresis [16]. Since iontophoresis decreases the skin s impedance, the passive flux was greater after iontophoresis than before iontophoresis [16]. Inada et al. [27] have also demonstrated for tetraethylammonium ion and mannitol that their passive and iontophoretic fluxes are related to the reciprocal of the skin s resistance. In addition, Inada et al. [27] showed that the higher... 

A good phase-transfer catalyst must be soluble in both aqueous and nonpolar organic solvents. Use SpartanView to compare electrostatic potential maps ofbenzyltrimethyl-ammoniuni ion, tetraethylammonium ion, and tetrabenzylammoniuni ion. Which ion is likely to be the most water-soluble, and which the least water-soluble ... 

Tavcar et al have used sol-gel derived Ce02-Ti02 film deposited onto indium-tin-oxide (ITO) glass for amperometric detection of counter ions (Li+, Na+, K+, NH/ and tetraethylammonium ions). The amperometric sensor has linearity over the range, 4 x 10"4 -4.0 x 10"3 mol l"1 which is dependent on the Li+ concentration and detection limit is 2 x 10"5 mol/L [84],... 

Perchlorate salts of tetraalkylammonium ions were chosen as electrolytes for this study, because they reduce hydrogen evolution. The chain length of the alkyl group was varied, i.e., ethyl, propyl, butyl, and octyl. A decrease in photocurrent was observed when the carbon chain length was increased. The surface state resistance was found to increase with increase of chain length. Correspondingly, a decrease in surface state capacitance was observed. These results indicate that tetraethylammonium ions are adsorbed stronger than tetrabutylammonium ions. 

TABLE 3 Concentrations of Products After Shaking for 4 h W Containing 02 (Saturated with Air), 1CT3 M (R4N+)2S04 and 0.1 M Phosphate Buffer (pH = 7.0) with DCE Containing 10-3 M CQH2. TPenA+, TBA+ and TEA+ Denote Tetrapentylammonium, Tetrabutylammonium and Tetraethylammonium Ions, Respectively... 

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