Quarternary ammonium cation

The addition of polar molecules to electrolyte solutions effects a much larger change in conductance if low dielectric solvents are employed In a series of papers Gilkerson et a/. studied the ion-molecule interaction of tertiary and quarternary ammonium cations with Lewis bases in low dielectric solvents, like o-dichlorobenzene, chlorobenzene or 1,2-dichloroethane. The change of the ion-pair association constant with concentration of an additive L was attributed to the formation of 1 1 cation-molecule complexes ... 

Other functional core moieties include stable TEMPO-based radicals for controlled radical polymerization,342 crown ethers,343 344 hexacyclenes,170 poly-(quarternary ammonium) cations,345 ethylene thio-lates,346,347 calixarenes,348-352 cyclodextrins,178 inorganic clusters,93-95 340 353,354 dichalcogenides,355 and silses-quioxanes.356... 

Organic compounds used in binding studies with melanins were mostly bases, often positively charged (quarternary ammonium cations). Paraquat and diquat studied both in vitro and in vivo were found to bind strongly to eye melanin, and the cation-exchange mechanism was fully identified (344). 

Cationic, anionic, and amphoteric surfactants derive thek water solubiUty from thek ionic charge, whereas the nonionic hydrophile derives its water solubihty from highly polar terminal hydroxyl groups. Cationic surfactants perform well in polar substrates like styrenics and polyurethane. Examples of cationic surfactants ate quaternary ammonium chlorides, quaternary ammonium methosulfates, and quaternary ammonium nitrates (see QuARTERNARY AMMONIUM compounds). Anionic surfactants work well in PVC and styrenics. Examples of anionic surfactants ate fatty phosphate esters and alkyl sulfonates. 

Cationic Detergents Cationic detergents are quarternary ammonium salts of amines with acetates, chlorides or bromides as anions. Cationic part... 

Sulfonic acid cation-exchange resin Quarternary ammonium... 

The first two processes are called thermal, because they can also be induced by classical Joule- or non-laser radiative heating, usually in conjunction with heat conduction to the sample surface. Thermal evaporation of cations of quarternary ammonium salts and anions of sodium tetraphenylborate has been demonstrated by several groups (13. 1, 15). Such a thermal evaporation of ions, common for metals and inorganic salts such as alkalihalides, had not originally been expected to occur for organics as well. It should be most pro-... 

Enantiomers (dansyl Cationic polyelectrolyte amino acids) (393) quarternary ammonium... 

The catalytic activity of quarternary ammonium salt usually depends on the corresponding catalyst cation and counter anion[2]. For a series of tetraalkylammonium chlorides, the activity increased in the order of TP AC < TBAC < TOAC. Bulky quaternary salts, having longer distance between cation and anion, are generally known to exhibit higher activity in activating anions[3]. This explains why they are more effective in nucleophilic attack of the anion to oxirane ring of GVE. Table 1 also shows that the rate constant with different halide anions of the quaternary ammonium salts decreases in the order of Cf > Bf > T. This is consistent with the nucleophilicity of the halide anions. 

Electrochemical syntheses of Zintl ions were proposed and preliminarily investigated by E. Zintl himself as early as 1933, but was not revitalized until the 1980s.f This synthetic route, as currently applied by Haushalter et involves the application of a cathodic current to an electrode made from the alloy under study in a supporting electrolyte of large cations (typically, solutions of quarternary ammonium or phosphonium salts). The cathodic production of polyanions is rapid and normally allows for the isolation of crystalline compounds in a few days. 

For the synthetic fibre poly(ethylene terephthalate) it is very important to impart antistatic properties to it [175]. Studies on the effect of the structure of cationic surfactants on the half-life time of static charge decay and surface resistivity (Rs) of PET fibres show best results with a methylated quarternary ammonium salt of a stearyl amine-ethylene oxide adduct or hydrochloride of a lauryl amine-EO adduct with 10 EO. 

Cationic copolymers of acrylate and methacrylates bearing quarternary ammonium groups Eudragit RL 30D (aqueous dispersion), insoluble and pH-independent polymer for sustained-release formulations, high-permeability films... 

Long-chain quarternary ammonium compounds (QACs) are cationic surface active agents according to the general formula... 

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