Electrolyte tetraethylammonium

The formation of the dicyclopropylmercury alone or in combination with the adsorbed radical type intermediates accounts for the observation that the substrate disappears at a faster rate than the reduction product appears The dicyclopropylmercury can then accept an electron to produce the anion and a cyclopropylmercury radical which in combination with the mercury surface becomes an adsorbed radical (equation 7) which can be recycled through the pathway of equation 5 or equation 6. The anions formed in equation 3, equation 5, and equation 7 react at the surface with acetonitrile solvent (equation 8) to yield the hydrocarbon. When deuterated acetonitrile was used the hydrocarbon isolated contained 76% deuterium The anion can also react with the electrolyte, tetraethylammonium bromide, in an elimination reaction (equation 9) to produce hydrocarbon, ethylene and triethylamine, all of which have been identified in the reaction mixture ... 

All chemicals, if not otherwise mentioned, were reagent grade and used without further purification. Polymerization solutions consisted of pyrrole monomer (Sigma Chemical Company) dopant electrolyte (tetraethylammonium-p-toluene) sulphonate, Alfa/Aldrich Chemical Company) and distilled water. The ratio of pyrrole dopant concentration was maintained at 3 1, as this has previously been found to be optimum, and the initial pyrrole concentration was 0.75 moll. ... 

In pioneering studies [47], the SECM feedback mode was used to study the ET reaction between ferrocene (Fc), in nitrobenzene (NB), and the aqueous mediator, FcCOO, electrochemically generated at the UME by oxidation of the ferrocenemonocar-boxylate ion, FcCOO. Tetraethylammonium perchlorate (TEAP) was applied in both phases as the partitioning electrolyte. The results of this study indicated that the reaction at the ITIES was limited by the ET process, provided that there was a sufficiently high concentration of TEAP in both phases. 

FIG. 9 Upper potential values, a.sds lower potential values, b.sds of the first oscillation at the interface between phases o and wl of the octanol membrane (A), interfacial potential of a two-phase octanol-water system in the absence of SDS, c.sds (B) and those in the presence of 10 mM SDS (in the case of inorganic electrolyte, 1 mM), d.sds (C)- TMACI tetramethylammonium chloride TEACI tetraethylammonium chloride TPACI tetrapropylammonium chloride TBACI tetra-butylammonium chloride AcNa sodium acetate PrNa sodium propionate, BuNa sodium n-butyrate VaNa sodium w-valerate. (Ref 27.)... 

Figure 2.62 The l/t transient obtained during the growth of a poly thiophene film on a 6.30 cm2 Pt electrode at 1.80V vs. SCE in acetonitrile/0,1 M tetraethylammonium tetrafluoroborate electrolyte. At f = 7 s, the potential was switched to OV to terminate the growth process. After...

Some typical results are shown in Table 2. The table shows that oxidation of conjugated dienes such as isoprene, piperylene (1,3-pentadiene), cyclopentadiene and 1,3-cyclohexadiene with a carbon anode in methanol or in acetic acid containing tetraethylammonium p-toluenesulfonate (EtjNOTs) as the supporting electrolyte yields mainly 1,4-addition products2. 1,3-Cyclooctadiene yields a considerable amount of the allylically substituted product. 

The original process used aqueous tetraethylammonium ethylsulfate as the electrolyte, a lead cathode, and a lead-silver alloy anode. The Mark II process, commercialized in the mid-1970s, uses an emulsion of acrylonitrile in aqueous sodium phosphate containing a salt of the hexamethylene-bis-(ethyldibutylammonium) cation. The process was invented in 1959 by M. M. Baizer at Monsanto Corporation, St. Louis, MO. It was commercialized in 1965 and has been continuously improved ever since. The process is also operated in Japan by Asahi Chemical Industry Company. In 1990, the world production of adiponitrile by this process was over 200,000 tonnes per year. 

Electrolysis of b-al Ionic ketone 61 at a controlled cathode potential of-2.43 V (versus Ag/AgI) in anhydrous DMF using tetraethylammonium p-toluenesulfonate as co-electrolyte provides the derived ketyl radical that undergoes a 5-exo-trig selective ring closure, presumably via transition structure 62 (Scheme 11.19). The cyclization product is further reduced and subsequently protonated to afford traus-configurcd cyclopentanol 63 as single diastereomer in a total yield of 55% [80]. 

Table 11 Anodic oxidation of ST-Bu4NNu in acetonitrile with tetraethylammonium perchlorate as supporting electrolyte."...

Pairs of platinum plate (2x5 cm) were set in a cell with 1 mm spacing as the working and the auxiliary electrode (Figure 2). Reference electrode was Ag/AgCl. The solution (50 ml) of phenol (0.005 mol) and electrolyte (0.01 mol) such as tetraethylammonium bromide and tetraethylammonium perchrolate was kept under nitrogen atmosphere in the cell. The electrolysis was carried out with constant potential or current density (10 mA/cm2) which was supplied by a potentiogalva-... 

The oxidation of enol ethers at a reticulated vitreous carbon anode [2, 3] (Scheme 1) in a mixture of methanol/THF containing tetraethylammonium tosylate as the electrolyte and 2,6-lutidine as the base leads to substituted tetrahydrofu-ran and tetrahydropyran rings in good yields (51-96%). The major product obtained had a trans-stereochemistry. The cyclization failed to make seven-membered ring products. In order to determine the... 

Yoshida and coworkers [63, 64] studied the oxidative cycloaddition of cyclic 1,3-dione (1,3-cyclopentanedione and some 1,3-cyclohexanediones) and olefins in various solvents and electrolytes. The best results were obtained in acetonitrile containing tetraethylammonium tosylate as electrolyte (97% yield with 5,5-dimethyl-l,3-cyclohexadione and styrene) (Scheme 45). 

The one-electron reduction of 3,4,5-trimethoxyphenyl glyoxal with potassium tert-butoxide in DMSO gives rise mainly to the ctT-semidione, whereas on electrolysis in dimethylformamide, in the presence of tetraethylammonium perchlorate as the carrier electrolyte, the main product is the trans isomer (Sundaresan and Wallwork 1972 Scheme 3.47). 

When a tetraalkylammonium cation is used as a counterion in solvents of high polarity, such as AN or DME, the alkyl groups of the cation hinder the mutual approach of species with different charges. Ion pairs with the potassium cation are stable. This follows from a comparison of the polarographic behavior of the three isomeric dinitrobenzenes in the same solvent (DMF) using tetraethylammonium or potassium perchlorate as the carrier electrolyte (Todres 1970). The halfwave potentials corresponding to the conversion of p- and m-dinitrobenzenes into anion-radicals are independent of whether tetraethylammonium or potassium counterions are employed. The anion-radical is formed from o-dinitrobenzene at a potential that is less negative by almost 100 mV when... 

Shono et al. (1979) recommend the use of thioanisole as a catalyst that allows lowering the electrode potential in the oxidation of the secondary alcohols into ketones. The cation-radical of thioanisole is generated at a potential of up to +1.5 V in acetonitrile containing pyridine (Py) and a secondary alcohol. (The background electrolyte was tetraethylammonium p-toluene sulfonate.) Thioanisole is recovered and, therefore, a ratio of RXR )CHOH PhSMe = 1 0.2 is sufficient. The yield of ketones depends on the nature of the alcohol and varies from 70 to 100%. 

Baizer, working at the Monsanto Company, showed that good yields of adiponitrile are obtained from aqueous solutions by reduction at mercury or lead in the presence of a high concentration of quaternary ammonium salt [62]. Tetraethyl-ammonium toIuene-4-sulphonate was favoured as electrolyte. The first commercial plant operating the process was commissioned in 1965. It used a divided cell system with a lead cathode and aqueous tetraethylammonium ethylsulphate as electrolyte, with the addition of acid to regulate the pH. A lead anode with an anolyte of dilute sulphuric acid was employed. 

Oxidation of amides at a rotating platinum electrode in acetonitrile with tetraethylammonium 4-toluenesulphonate as electrolyte. 

In dry aprotic solvents such as acetonitrile [28] with tetraethylammonium bromide as supporting electrolyte or dimethylformamide [29] with sodium perchlorate as supporting electrolyte, the ( ) / rneso ratio for pinacols rises substantially in favour of the ( )-form. Reduction of acetophenone in dimethylformamide in the presence of europium(ni) chloride leads to the ( )-pinacol only. Under these reaction conditions, europium(ii) is formed and dimerization occurs with the involvement of this ion and the ketone in a complex [30]... 

The electrochemical rate constants of the Zn(II)/Zn(Hg) system obtained in propylene carbonate (PC), acetonitrile (AN), and HMPA with different concentrations of tetraethylammonium perchlorate (TEAP) decreased with increasing concentration of the electrolyte and were always lower in AN than in PC solution [72]. The mechanism of Zn(II) electroreduction was proposed in PC and AN the electroreduction process proceeds in one step. In HMPA, the Zn(II) electroreduction on the mercury electrode is very slow and proceeds according to the mechanism in which a chemical reaction was followed by charge transfer in two steps (CEE). The linear dependence of logarithm of heterogeneous standard rate constant on solvent DN was observed only for values corrected for the double-layer effect. 

Polarographic Halt-Wave Potentials El, in Volts (vs. SCE), for Certain Metal Cations in the Presence of Either Amirfonia-Ammonium Chloride Mixture or Tetraethylammonium Hydroxide as the Indifferent Electrolyte... 

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