Methylammonium chloride

OL,, -Trinitro-Propionaldehyde methyl imide ( 03,7,7-Trinitro-Propyliden]-methyl-amine). CH3.N CH.CH(N02).CH(N02)2 mw 206.14 N 27.19% white crysts. V sol in acet si sol in w insol in eth. Prepn is by reacting a,j3 J3-trinitro-propionaldehyde suspended in ammonia with an excess of methylammonium chloride. The imide is recovered by acidifying the mixt with HC1... 

Self-Test 10.13A Estimate the pH of 0.10 m CH3NH3Cl(aq), aqueous methylammonium chloride the cation is CH3NH3. ... 

Concerning the SLN produced by hot homogenization as described by Olbrich et al. [19], as lipidic matrix Compritol ATO 888 or paraffin were used, as tenside a mixture of Tween 80 and Span 85 was used, and as charge carrier either EQ1 [N,N-di-(()-s(eaoryI e(liyI)-.V,A -di methylammonium chloride] or cetylpyridinium chloride were used. The resulting particles were characterized by size between 101 and 105 nm and showed zeta potentials around 40 mV at pH 7.4. 

In order to construct the L-asparagine derivative of per-O-acetylated 0-(2-acetamido-2-deoxy-/ -D-glucopyranosyl( 1 — 4)-2-acetamido-2-deoxy-D-glucose (7), Spinola and Jeanloz (13) used (the sensitive) silver azide for conversion of the a-chloro anomer of the chitobiose derivative 8 into the / -azido derivative 9. Kunz and associates (14,15) have accomplished the conversion of the a-chloro anomer of 8 into 9 using sodium azide in the presence of tri-n-octyl-methylammonium chloride as a phase-transfer catalyst in chloroform water. 

The third liquid catalyst-philic phase was constimted in the majority of cases by Aliquat 336 [tricapryl-methylammonium chloride, (CgHi7)3N CH3Cl A336], a well-known phase-transfer agent that is liquid at room temperature, and that dissolves in toluene and in iso-octane (Figure 6.15n). The peculiarity here is that, when water (even a drop) is added to the A336/isooctane solution, three liquid phases separate out (Figure 6.15h). 

Entropy of Methylammonium Chloride. Heat capacities for this solid in its various crystalline modifications have been determined [10] precisely down to 12 K. Some of these data are summarized in Figure 11.3. There are three crystalline forms between OK and 298K. One can calculate the entropy by integrating Equation (11.21) for each allotrope in the temperature region in which it is most... 

Figure 11.3. Heat capacities of the three allotropic forms, a, (3, and y, of methylammonium chloride [10]. The dashed curve represents the heat capacity of the metastable, supercooled y form.

Methylammonium chloride exits in several crystalline forms, as is evident from Figure 11.3. The thermodynamic properties of the (3 and 7 forms have been investigated by Aston and Ziemer [10] down to temperatures near 0 K. Some of their data are listed below. From the information given, calculate the enthalpy of transition from the (3 to the 7 form at 220.4 K. 

Ejfect of temperature Luisi et al. [26] reported that the temperature markedly affected the transfer of a-chymotrypsin in a chloroform-trioctyl-methylammonium chloride (TOMAQ system. By increasing the temperature from 25-40°C, about 50% higher transfer yield was realized. No appreciable transfer of glucagone took place at room temperature, whereas transfer at 37°C was possible. These results contradict work by Dekker et al. [27], who studied the back stripping (desolubilization) of a-amylase from a TOMAC/isooctane/octanol/Rewopal HV5 system by increasing the temperature. This caused a decrease in Wo with increasing temperature and, as a result, the a-amylase was expelled from the reverse micelle phase. 

As for solvents, liquid ammonia or dimethylsulfoxide are most often used. There are some cases when tert-butanol is used as a solvent. In principle, ion-radical reactions need aprotic solvents of expressed polarity. This facilitates the formation of such polar forms as ion-radicals are. Meanwhile, the polarity of the solvent assists ion-pair dissociation. This enhances reactivity of organic ions and sometimes enhances it to an unnecessary degree. Certainly, a decrease in the permissible limit of the solvent s polarity widens the possibilities for ion-radical synthesis. Interphase catalysis is a useful method to circumvent the solvent restriction. Thus, 18-crown-6-ether assists anion-radical formation in the reaction between benzoquinone and potassium triethylgermyl in benzene (Bravo-Zhivotovskii et al. 1980). In the presence of tri(dodecyl)methylammonium chloride, fluorenylpi-nacoline forms the anion-radical on the action of calcium hydroxide octahydrate in benzene. The cation of the onium salts stabilizes the anion-radical (Cazianis and Screttas 1983). Surprisingly, the fluorenylpinacoline anion-radicals are stable even in the presence of water. 

Dimethylxylaramide 1- To a 250 mL round-bottom flask equipped with a magnetic stirrer was added methanol (50 mL) and the xylaric acid - methanol esterification product (6.7 mmol in 10 mL of methanol) prepared as described above. Triethylamine (6.5 mL, 46 mmol) and methylammonium chloride (1.0 g, 14.7 mmol) were then added to the methanol solution and the reaction mixture was refluxed with stirring overnight. The mixture was concentrated and the residue was washed several times with methanol. The... 

Bases can be considered in the same way. Thus, methylamine will react with aqueous HCl to produce methylammonium chloride and water. 

A solution of 50 mmol of the hydrochloride of the amino acid ethyl ester 5 is dissolved in 100 mL of ethanol and added during 1 h to 100 mL of 8M methanamine in ethanol at 0 C. After 4 h the mixture is allowed to reach 20 CC and stirred at that temperature for 30 h. 300 mL of diethyl ether is added, the mixture is cooled to — 20 JC and the methylammonium chloride is filtered off. The solvents are evaporated off under vacuum and the residue is dissolved in 40 mL of CH2C12, recooled to — 20 °C and additional precipitated methylammonium chloride is filtered off. After evaporation of the solvent the residual A-methylamide is sufficiently pure to use in the next step without further purification. 

Indeed, we have found that N-(3-chloro-2-hydroxypropyl)trimethylam-monium chloride is readily converted with sodium hydroxide to glycidyltri-methylammonium chloride, which obviously further reacts at a slower rate with lignin nucleophiles to form cationic lignin derivatives. 

You should learn to recognize whether a compound is acidic or basic. The salt methylammonium chloride, for example, dissociates in aqueous solution to give methylammonium cation and chloride ... 

Methylammonium ion, being the conjugate acid of methylamine, is a weak acid (Reaction 6-28). Chloride is the conjugate base of HC1, a strong acid. In other words, Cl- has virtually no tendency to associate with H+, or else HC1 would not be a strong acid. Methylammonium chloride is acidic because methylammonium ion is an acid and Cl is not a base. 

Difluoromethoxy-2-chloro-l,l,l-tnfluoroethane and potassium fluoride produce 2-difluoromethoxy-1,1,1,2-tetrafluoroethane [50] The yield of the latter reaction is improved by adding a phase transfer catalyst or crown ether, tetra-methylammonium chloride, tetrabutylammomum chloride, or 18-crown-6 with a solvent like sulfolane can be used for this purpose [57] (equation 32)... 

Potassium r-butoxide-Hexamethyl-phosphoric triamide, 252 Potassium r-butoxide-Xonotlite, 254 Potassium hydroxide, 258 Potassium hydroxide-18-Crown-6, 258 Potassium hydroxide-Tricaprylyl-methylammonium chloride, 258 Sodium hydroxide-Methyltrioctyl-ammonium chloride, 192 Sodium hydroxide-Triethyl(2-methyl-butyl)ammonium bromide, 239 Sodium hydroxide-N-(p-Trifluoro-methylbenzyl)cinchoninium bromide, 325... 

Exercise 14-12 Would you expect 4-bromonitrobenzene or (4-bromophenyl)-tri-methylammonium chloride to be more reactive in bimolecular replacement of bromine by ethoxide ion Why ... 

Many compounds have been tested simultaneously with (2-chloroethyl)tri-methylammonium chloride on Thatcher wheat, to ascertain, if possible, whether these chemicals were affecting a particular metabolic process. Other cholinesterase inhibitors such as eserine, diisopropyl fluorophosphate, and nitrogen mustard, neither negated the effect from (2-chloroethyl)trimethylammonium chloride nor altered the growth of the plant themselves. Many other substances were also without effect on the action of (2-chloroethyl)trimethylammonium chloride. A very slight reversal of the alteration by (2-chloroethyl)trimethylam-monium chloride was obtained by 10 2 and 10 3 M choline, betaine, and adenine. Only gibberellin completely and rapidly reversed the shorter growth pattern of a plant which had been treated with (2-chloroethyl)trimethylammonium chloride. 

During the polymerization, DADMAC acts not only as a monomer, but also as a low molecular weight electrolyte which suppresses the Coulombic interactions. The addition of neutral low molecular salts (NaCl [10], NaBr [52], tetra-methylammonium chloride [13]) leads in the same manner to a polymerization rate increase. Even though the viscosity of the monomer solution increases with the concentration (Fig. 5), it should be taken into account that the viscosity in the polymerizing system is more strongly influenced by the polymer than by the monomer, even at low conversions [51]. 

Sol-gel methods have been used to form membranes on sensor surfaces by the mixing of the ion-sensitive molecule with alkoxysilanes which then crosslink to form a hard, transparent coating on the sensor. For example, tridodecyl-methylammonium chloride-doped films were used as a chloride sensor and showed Hofmeister-type selectivity [91]. Long cure times (several days), however, represent a disadvantage in this process [91]. 

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