Quaternary ammonium compounds properties

CH3)4NC1. A quaternary ammonium compound. Properties White, crystalline solid. D 1.1690 (20/ 4C), mp (decomposes). Soluble in water and alcohol insoluble in ether, also available as a 50% solution. 

Physical Properties. Most quaternary compounds are soHd materials that have indefinite melting poiats and decompose on heating. Physical properties are determined by the chemical stmcture of the quaternary ammonium compound as well as any additives such as solvents. The simplest quaternary ammonium compound, tetramethylammonium chloride [75-57-0] is very soluble ia water (163) and iasoluble ia nonpolar solvents. As the molecular weight of the quaternary compound iacreases, solubiUty ia polar solvents decreases and solubiUty ia nonpolar solvents iacreases (164—166). For example, trimethyloctadecylammonium chloride [112-03-8] is soluble ia water up to whereas dimethyldioctadecylammonium chloride [107-64-2] has... 

Disinfectants. Several disinfecting agents can be used in hatcheries and two are of particular interest. Because they are not considered dmg or food additive uses by FDA, povidone—iodine compounds can be used to disinfect the surface of eggs (9). Benzalkonium chloride [68424-85-1] and benzethonium chloride (quaternary ammonium compounds), are allowed at 2 mg/L by FDA to disinfect water containing fish. These compounds are also known to have therapeutic properties, especially against external bacteria (9). 

Chemical disinfectants are limited in their use as air sterilants because of their irritant properties when sprayed. However, some success has been achieved with atomized propylene glycol at a concentration of 0.05-0.5 mgH and quaternary ammonium compounds (QACs) at 0.075% m be used. For areas which can be effectively sealed off for fumigation purposes, formaldehyde gas at a concentration of 1-2 mg H of air at a relative humidity of 80-90% is effective. 

It is difficult to prove that quaternary ammonium compounds can cross lipid bilayers using cell uptake experiments, since several mechanisms may be operative, and separating contributions from each may be very difficult [1]. It may be an advantage to use PAMPA to investigate transport properties of permanently ionized molecules. Of all the molecules whose permeabilities were measured under iso-pH conditions in 2% DOPC/dodecane, verapamil, propranolol, and especially quinine seem to partially violate the pH partition hypothesis, as shown in Figs. 7.47a-c. In Fig. 7.47c, the solid line with slope of +1 indicates the expected effective permeability if the pH partition hypothesis were strictly adhered to. As can be seen at pH 4... 

Taking into consideration its physico-chemical properties, removal efficiencies, low biodegradability, predicted environmental levels, toxicity, and the need to provide sufficient safety margins for aquatic organisms, the demand for alternative cationic surfactants arose. Since 1991, DTDMAC has been replaced in some European countries due to producer s voluntary initiatives with new quaternary ammonium compounds, the esterquats. These contain an ester function in the hydrophobic chain (Table 1.3) that can be easily cleaved, releasing intermediates that are susceptible to ultimate degradation [24-26]. The effects of the phasing-out and replacement of DTDMAC can be demonstrated by the results of a Swiss study, where the surfactant... 

The simultaneous ionic and covalent character of quaternary ammonium compounds (197a) is central to most of their applications. TV-Quatemized heteroaromatic compounds possess many of the properties of 197a, and will be mentioned occasionaly in this chapter. In Table 4 are listed some quaternary ammonium compounds that have found industrial application. Many analytical methods make use of this class of compounds both as essential reagents or as accessories however, in the present chapter quaternary ammonium compounds will appear only as analytes. 

Buscopan contains hyoscine butylbromide, which is a quaternary ammonium compound with antimuscarinic properties. It is used as an antispasmodic and therefore may be useful in irritable bowel syndrome. Hyoscine butylbromide, as with all antimuscarinics, must be used with caution in patients with prostatic hypertrophy, as they may lead to urinary retention. 

Paraquat (1,1 dimethyl, 4,4 bipyridyl) is a nonselective contact herbicide. It is used almost exclusively as a dichloride salt and usually is formulated to contain surfactants. Both its herbicidal and toxicological properties are dependent on the ability of the parent cation to undergo a single electron addition, to form a free radical that reacts with molecular oxygen to reform the cation and concomitantly produce a superoxide anion. This oxygen radical may directly or indirectly cause cell death. Diquat, l,T-ethylene-2,2 -dipyridylium, is a charged quaternary ammonium compound often found as the dibromide salt. The structure of diquat dibromide and that of the closely related herbicide paraquat can be seen in Fig. 4.5. 

Mechanism of Action A quaternary ammonium compound that has anticholinergic properties and that inhibits action of acetylcholine at postganglionic parasympathetic sites. Therapeutic Effect Reduces gastric secretions and urinary frequency, urgency, and urge incontinence. 

Some quaternary ammonium compounds arc potent germicides, toxic in small (mg/L range) quantities to a wide range of microorganisms. Bactericidal, algicidal, and fungicidal properties are exhibited, Many quaternaries are considered to be moderately to severely irritating to the skin and eyes. 

Most uses of quaternary ammonium compounds can be expected to lead to these compounds eventual release into wastewater treatment systems except for those used in drilling muds, Useful properties of the quaternaries as germicides can make these compounds potentially toxic to sewer treatment systems. It appears, however, that quaternary ammonium compounds are rapidly degraded in the environment and strongly sorbed by a wide variety of materials. 

In addition, the quaternary ammonium compounds mostly possess strong affinity for the cellulosic fiber, whereby the insoluble reaction product is anchored even more firmly with the dye on the fiber. This high affinity can, however, also result in nonuniform improvements in fastness properties. This behavior also prevents the use of circulating liquor dyeing machines, because even with addition of aftertreatment agent in portions (e.g., in the case of wound packages) completely uniform aftertreatment can not be guaranteed. 

The chloride is used to manufacture silicones, tetramethyl lead and triptane (2,2,3 trimethylbutane). Lesser uses include the manufacture of butyl rubber, higher halogenated methanes, methyl cellulose, quaternary ammonium compounds, methyl mercaptan, methionine, fungicides and pesticides (primarily the Me-arsenate herbicides). Recently the chlorinated fluorocarbons have replaced CH3CI as high volume refrigerants and propellants (ref. 32) Tables 12 and 13 list the chemical and physical properties and potential numbers of workers exposed to the monohalomethanes. 

Many quaternary ammonium compounds are known to possess bactericidal properties, a factor taken into account in the marketing of quaternary ammonium fabric softeners. However, in the spirit of the European REACH initiative (See Chapter 5), many of the ionic liquids in common use are being scrutinized for toxicity potential. For instance, in the aquatic world there are indications that exposure to as little as 10 mg/liter causes skin and gill hyperplasia in zebrafish, leading to respiratory... 

PVC antistatic agents Quaternary ammonium compounds Antistatic properties... 

Alkali is not capable of dissolving native cellulose. Only depolymerized cellulose fragments with a low degree of polymerization are alkali soluble. Certain quaternary ammonium compounds are more effective resulting in full solubility, A mixture of dimethyl sulfoxide and paraformaldehyde (DMSO-PF) has interesting properties as a cellulose solvent. However, its effect depends at least partly on the formation of a hydroxymethylcellulose derivative. The most important cellulose solvents are metal complexes of... 

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