Quaternary ammonium salt groups

The procedure recommended for amination is that of Pepper et al. (13). Polymers containing quarternary, tertiary, secondary, and primary amines were prepared. In all cases, the dried polymer had to be swelled with a solvent such as THF or dioxane. The amine was then added, which reacted with the chloromethyl groups to produce polymer-bound amine groups. All the steps were carried out under an inert atmosphere. Quaternary ammonium salt groups were obtained by reacting 20 g of polymer swollen in dioxane and 100 ml of cold anhydrous trimethylamine at 0°C. The mixture was kept at 0°C for 2 days with stirring under N . The polymer was then washed sequentially with 2N HC1, 0.1N NaOH, 2N HC1, 2N NaCl, and finally deionized water until the effluent was chloride free. 

These fibres are made from a melt-extrudable composition containing a polyolefin and an antimicrobial siloxane quaternary ammonium salt, which can be a trisiloxane having a pendant quaternary 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 moiety is terminated at each end by a quaternary ammonium salt group. The anion can be one, which does not adversely affect the heat stability of the salt. 

A silane containing hydroxyl and quaternary ammonium salt groups was treated with a triisocyanate to prepare a biocidal film that was active against Escherichia coli for as long as 1 month.188 Cellulose was treated with the appropriate trimethoxysilane to attach a phosphonium salt.189 Polyphosphonium salts based on polystyrene have been prepared with spacers of varying lengths between the aromatic ring and the phosphorus atom.190 Polymeric dichlorohydantoins were used to disinfect potable water... 

Synthesis and Antibacterial Properties of Polysiloxanes-bearing Quaternary Ammonium Salt Groups... 

Allylic amine is a less reactive leaving group[7], but the allylic ammonium salts 214 (quaternary ammonium salts) can be used for allylalion(l30,131]. Allylic sulfonium salts are also used for the allylation[130]. The allylic nitrile in the cyclic aminonitrile 215 can be displaced probably via x-allylic complex formation. The possibility of the formation of the dihydropyridinium salts 216 and subsequent conjugate addition are less likelyfl 32],... 

Ammonium salts that have four alkyl groups bonded to nitrogen are called quaternary ammonium salts... 

In spite of being ionic many quaternary ammonium salts dissolve m nonpolar media The four alkyl groups attached to nitrogen shield its positive charge and impart lipophilic character to the tetraalkylammonium ion The following two quaternary ammonium salts for example are soluble m solvents of low polarity such as benzene decane and halo genated hydrocarbons... 

Quantum (Section 13 1) The energy associated with a photon Quaternary ammonium salt (Section 22 1) Salt of the type R4N X The positively charged ion contains a nitrogen with a total of four organic substituents (any combination of alkyl and aryl groups)... 

Basic Extractants. Only long-chain quaternary ammonium salts, R3NCH3 X , ia which R represents Cg—0 2 groups and X nitrate or thiocyanate, are effectively used for REE separations (see Quaternary ammonium compounds). The extractant reacts with REE according to an anion-exchange reaction ... 

The quaternary ammonium salts (QAS) are widely used as ionofores of ion-selective electrodes and extractants of metals halogenic anion complexes. The influence of the QASes nature with various methyl groups contents on the cadmium extraction from bromide media has been investigated. 

The amino functional group is not commonly encountered in steroid synthesis except perhaps in steroidal alkaloids. However, certain elimination reactions have been shown to have theoretical and limited preparative importance, largely due to the efforts of McKenna and co-workers. The Hofmann rule for 2 elimination predicts that alkaline elimination of quaternary ammonium salts will occur towards the carbon carrying the most hydrogen atoms cf. the converse Saytzeff orientation, above). In cyclohexyl systems, the requirement for diaxial elimination appears to be important, as in other 2 eliminations, and the Hofmann rule frequently is not obeyed [e.g., (116) (117)]. 

Tertiary amines from quaternary ammonium salts by migration of an alkyl group... 

Compounds containing a nitrogen atom with four attached groups also exist, but the nitrogen atom must carry a formal positive charge. Such compounds are called quaternary ammonium salts. 

Quaternary ammonium salt (Section 24.1) An ionic compound containing a positively charged nitrogen atom with four attached groups, R4N+ X-. 

The dialkylamino, especially the dimethylamino, group in a cyclopentenone of type 67 can be alkylated with methyl iodide to yield a quaternary ammonium salt. Upon treatment with a base, these quaternary ammonium salts undergo... 

This is an Sn2 process, since inversion is found at R. Another good leaving group is NTS2 ditosylamines react quite well with acetate ion in dipolar aprotic solvents RNTs2 4- OAc — ROAc. Ordinary primary amines have been converted to acetates and benzoates by the Katritzky pyrylium-pyridinium method (p. 447). Quaternary ammonium salts can be cleaved by heating with AcO in an aprotic solvent. Oxonium ions can also be used as substrates RsO -f R COO —> R COOR R2O. 

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