Quatemaiy ammonium

Data obtained for three different leaving groups are presented in Table 6.7. The results show that syn elimination is extensive for quatemaiy ammonium salts. With better leaving groups, the extent of syn elimination is small in the polar solvent DMSO but quite significant in benzene. The factors which promote syn elimination will be discussed shortly. 

Talafloc A process for decolorizing cane sugar syrup by precipitating the eoloring impurities with a long-chain quatemaiy ammonium salt. Invented in 1967 by M. C. Beimett at Tate and Lyle, United Kingdom. 

In order to avoid the necessity of adding a quatemaiy ammonium compound to solubilize the organotin derivative, a number of new, anionic, tributyltin salts of the type (RaR P) (BusSnCl ), where R = Ri = "Bu or Ph R = Ph, R = Bz, were prepared (440, 536). Although these contain discrete, trigonal, bipyramidal tributyldichloro-stannate anions (440), their solubility in water was found to be very low. 

The immobilisation of antibacterial coatings onto conductive materials such as stainless steel or carbon fibre used in orthopaedic implants was investigated by two methods. The formation of thin films by electrodeposition of polypyrrole doped with polyanions able to complex silver ions, and their characterisation by SEM, FTIR and microbiological testing is described. The alternative method, involving chemical grafting of a thin film of a quatemaiy ammonium polymer using a surface initiator, is also discussed. 2 refs. 

A non-woven web having antimicrobial properties is made from a melt extmdable composition, which contains a polyolefin and an antimicrobial siloxane quaternary ammonium salt, which may be a trisiloxane having a pendent quatemaiy ammonium group and a molec.wt. of from about 600 to 1,700 or an ABA-type siloxane having a polydispersity of up to about 3.0 and a weight-average molec.wt. of from about 800 to 2,000 in which a central siloxane moiety is terminated at each end by a quatemaiy ammonium salt group. The anion can be any anion, which does not adversely affect the thermal stability of the salt. 

The ion pair reagents for anions are usually quatemaiy ammonium salts such as phosphates and hydrogen sulfates. Several are shown in Table 19-3. ... 

Acetoqoat [Aceto] Quatemaiy ammonium salts germicide, sanitizing agent... 

Rematard. (Hoechst AG] Quatemaiy ammonium compds. retarders for dyeing c aaylic fibm with carbonic dyes. 

Tanaqiiad. [Sybron] Quatemaiy ammonium con wetting agent bactericide, sanitizer, dye retardant antistat... 

Noxandnm. [CecaSA] Quatemaiy ammonium derivs. antistatic, bactericidal emulsifier. 

The aforementioned poly(aminoamides) can be subjected to additional derivatization reactions. Some potential reactions include reaction with epichlorohydrin (to generate reactive functionalities), degradation of the polyamide chain (for repulping purposes), reaction with Quat 188 (to add pendant quatemaiy ammonium groups to the polymer chain), and reaction with 1,3-dichloropropane (to increase the molecular weight and to crosslink the polymer). 

Wenzl, S. Deutzmann, R. Hett, R. Hochmuth, E. Sumper, M., Quatemaiy Ammonium Groups in Silica-Associated Proteins. Angew. Chem. Int. Ed. 2004, 43, 5933-5936. 

A quatemaiy ammonium salt containing an electron-withdrawing group Z on one of the caibons attached to the nitrogen is treated with a strong base to give a rearranged tertiary amine. 

Anion Exchange. Extensive values of the selectivity coefficients for strongly basic anion resins of the quatemaiy ammonium types have been tabulated by Bauman and Wheaton, Kunin and McGarvey, and Gregor et al. " Gregor and cowoikers have shown two classes of ions those that exhibit little chimge in selectivity coefficient with resin composition, and those with composition-dependent selectivity coefficients. The latter presumably form clusters within the resin phase white the former are distributed randomly at equilibrium. 

The action of redox metal promoters with MEKP appears to he highly specific. Cohalt salts appear to he a unique component of commercial redox systems, although vanadium appears to provide similar activity with MEKP. Cohalt activity can he supplemented hy potassiiun and zinc naphthenates in systems requiring low cin-ed resin color lithium and lead naphthenates also act in a similar role. Quatemaiy ammonium salts (14) and tertiary amines accelerate the reaction rate of redox catalyst systems. The tertiary amines form beneficial complexes with the cobalt promoters, facilitating the transition to the lower oxidation state. Copper naphthenate exerts a imique influence over cin-e rate in redox systems and is widely used to delay cure and reduce exotherm development during the cross-linking reaction. 

Quatemaiy ammonium ions have four alkyl and/or aryl groups bonded to nitrogen, resulting in a positively charged species. 

The selectivity of the molecularly-imprinted NO3 ISE is much improved versus those based on the quatemaiy ammonium salts. For example, the log for perchlorate in this case is -1.24 relative to nitrate (fixed interference method). Thiocyanate, which was also a major interferent for the quatemaiy ammonium salt-based ISE, with log of 1.7 (24 is better discriminated against by the molecularly-imprinted ISE. For this nitrate-selective ISE the most important interference is chloride. 

The uncatalyzed epoxy reaction occurs far too slovdy for high-speed integrated circuit packaging procedures, which require reaction to be essentially complete in a few minutes at temperatures around 170°C. Tighter control over the reaction selectivity leads to greater product consistency and reliability. An appropiate catalyst or combination of catalysts can speed up the reaction and provide titter control over the reaction selectivity. Many types of catalysts have been used these include acids and bases, group 5a compounds (tertiary amines, phosphines), and quatemaiy ammonium complexes,... 

Linear low density polyethylene (LLDPE) of mark Dowlex-2032, having melt flow index 2.0 g/10 min and density 926 kg/m that corresponds to crystallinity degree of 0.49, used as a matrix polymer. Modified Na -montmorillonite (MMT), obtained by cation exchange reaction between MMT and quatemaiy ammonium ions, was used as nano filler MMT contents makes up 1-7 mass% [4]. 

Wittig rearrangement of benzylic quatemaiy ammonium salts upon treatment with alkali metal amides via die ammonium ylide intermediates. 

Chem. Descrip. Alkyl quatemaiy ammonium chloride and ethoxylated alkylamine... 

Cocamidopropyl) (2-hydroxy-3-sulfopropyl)ditnethyl quatemaiy ammonium compounds, hydroxides, inner salt. See Cocamidopropyl hydroxysuHaine Cocamidopropyl hydroxysuKaine... 

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