Ammonium compounds, substituted

Ammonium Compounds. Salts and hydroxides containing quadricovalent nitrogen are named as a substituted ammonium salt or hydroxide. The names of the substituting radicals precede the word ammonium, and then the name of the anion is added as a separate word. For example, (CH3)4N+I is tetramethylammonium iodide. 

Quaternary ammonium compounds are usually named as the substituted ammonium salt. The anion is Hsted last (3). Substituent names can be either common (stearyl) or lUPAC (octadecyl). If the long chain in the compound is from a natural mixture, the chain is named after that mixture, eg, taHowalkyL Prefixes such as di- and tri- are used if an alkyl group is repeated. Complex compounds usually have the substituents Hsted in alphabetical order. Some common quaternary ammonium compounds and their appHcations in patent Hterature are Hsted in Table 1. 

Copper alloys are attacked at high pH. However, attack is usually caused not by elevated pH alone but because of copper complexation by ammonia or substituted ammonium compounds. In fact, copper resists corrosion in caustic solutions. For example, corrosion rates in hot caustic soda may be less than 1 mil/y (0.025 mm/y). 

Ammonium hydroxide and substituted ammonium compounds corrode copper alloys. Wastage is faster when oxygen concentration and/or... 

The cationic agents used for their antimicrobial activity all fall within the group known as the quaternary ammonium compounds which are variously described as QACs, quats or onium ions. These are organically substituted ammonium compounds as shown in... 

Nitrite substitutes can be divided into seven chemical categories (1) amine benzoates (2) fatty acid amines (3) phosphate or carbonate silicates (4) organophosphates (5) amine borates (6) alkanolamines and (7) quaternary ammonium compounds ("quats"). Thus, the technology already exists for replacing nitrite with no loss in rust protection. However, most replacements for nitrite are more expensive, less effective, less likely to be compatible with other additives, and work by a different mechanism (12). It is therefore not surprising that fluids containing nitrite are still relatively com mon. 

Esterquats, quaternary carboxyalkyl ammonium compounds, have been developed as substitutes for the quats, especially DTDMACs which are applied as softeners in household products because they are resistant to degradation [42] and toxic [43,44]. Today, the esterquats are preferentially used (see Fig. 2.12.1(b)). As previously noted, the detection of all types of esterquats in environmental samples is difficult because of their tendency to adsorb at surfaces. Even in the inflows of wastewater treatment plants (WWTP) it is extremely difficult to find these compounds, which are reduced in toxicity [45] compared with the DTDMACs. One reason is that these carboxyalkyl ammonium compounds are not very stable in the environment. A second reason is that these compounds are not stable during the ionisation process. 

As the number of known coordination compounds increased, theories to explain their constitution were devised.35 Thomas Graham (1805-1869) is credited with originating the first theory of metal ammines, the so-called ammonium theory, in which metal ammines are considered as substituted ammonium compounds. Graham attempted to explain the constitution of compounds such as diamminecopper(II) chloride by the formula (1). 

Quaternary amines consist of four alkyl or aryl groups attached to an N atom and, therefore, may be considered substituted ammonium bases. Commonly, they are referred lo in the trade as quaternary ammonium compounds. An example is tetramethyl ammonium iodide. 

Si,Si-Dimethyl-Sila-Substituted Derivatives of Polymethylen-bis-Trimethyl-ammonium Compounds with Curare-Like Activity... 

The isomeric optically active substituted ammonium salts which have been reported by organic chemists are not readily explained by an ammonium theory such as has been wrongly assumed to have been established by the experiments of V. Meyer and M. T. Lecco—vide supra. J. C. Cain argued from the above hypothesis of the constitution of the ammonium compounds that the optical activity is the result of a similar spatial configuration as that assumed for the carbon compounds where the quadrivalent nucleus, say NCI", instead of quadrivalent carbon, is at the centre of a tetrahedron so that... 

Crown ethers of the type discussed in this section have been used as sensors, membranes, or materials for chromatography. Shinkai used cholesterol-substituted crown ether 10 as a sensor for chirality in chiral ammonium compounds (Scheme 16). It was found that the pitch of the cholesteric phase exhibited by 10 was changed upon addition of the chiral salt. As the wavelength of reflection for incident light depends on the pitch, a color change was observed that was visible to the naked eye [45, 46]. Such chirality sensing systems were known before but chromophores had to be bound to the crown ether in order to observe color changes [47]. This problem could be overcome by 10, which uses intrinsic properties of the chiral nematic phase. 

Quaternary compounds (substituted ammonium salts, methacholine chloride, mepenzolate bromide, phospholine iodide, etc.) approximately 10%... 

Extensive work by Yamaki and Tobishima was devoted to the effect of additives on Li cycling efficiency in ethers and alkyl carbonates [265], This included the use of cation complexing compounds (e.g., 12 crown 4, TMEDA), reactive organic compounds (e.g., quinoneimine derivatives), and adsorption compounds (e.g., large tetraalkyl ammonium chloride substituted with aromatic rings) [265],... 

The intermediate is a charged quaternary ammonium compound that results from Sn2 substitutions on three CH3I molecules by the amine nitrogen. E2 elimination occurs because the neutral N(CH3)3 molecule is a good leaving group. 

Most nonmetal borates reported in the literature are ammonium and substituted ammonium salts, hi general, boric acid forms salts with alkyl- or aryl-amines that are roughly as or more basic than pyridine. Depending on the reaction conditions, a number of different crystalline borates might be isolated from a given amine. However, the chemistry of substituted amine borates is dominated by the occurrence of pentaborates, and relatively few compounds in this class have been reported containing more basic borates anions. 

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