Methyl chloride solutions

The first study with an oxygen compound which was sufficiently rigorous to provide evidence on the question of co-catalysis was that of Farthing and Reynolds [61]. They showed that 3,3-bischloromethyl oxetan could be polymerised in methyl chloride solution by boron fluoride only in the presence of water. Tater, Rose [62] obtained kinetic evidence for the need for a co-catalyst in the system oxetan—boron fluoride—methyl chloride, and he interpreted the low reaction rate when no water was added as due to residual water he also showed that water and a hydroxyl-terminated polymer could act as co-catalysts. 

Isobutylene polymerizations were carried out by charging isobutylene, methyl chloride, and the alkylaluminum compound in methyl chloride solution and adding the t-butyl halide initiator in methyl chloride rapidly. Polymerizations ensued immediately and were over in 5-10 min. The reactions were terminated after 15 min by the addition of prechilled methanol. The polymers were dried in vacuum at 40° to constant weight and were characterized by number average and viscosity average molecular weights. All reactions were carried out in duplicate. 

Rose also derived heats of polymerization. The values he obtained were 20.0 kcalmole for polymerization in methyl chloride solution at —20°C and 19.3 kcalmole" for polymerization in a mixture of ethyl chloride and methyl chloride at —9°C. It is at once a bit unfortunate that this elegant piece of work was carried out as early as 1956 before catalysts leading to less complicated kinetics were discovered, and a tribute to Rose s careful work that he was able to sort out the many complications involved. No other detailed kinetic study of the polymerization of oxetane was made until many years later. In 1971 Saegusa et al. [52], reported a kinetic study of the polymerization of oxacyclobutane initiated by a BF3—THF complex. 

At the normal dose rates used in radiolysis this abstraction reaction is not quantitative (37) owing to competing radical-radical reactions, so that the methane produced is not a true measure of the radical yield. For example, for methyl chloride solutions the methane observed in the absence of radical scavengers is only 75% of the methyl radical detected with iodine. For methyl iodide the methyl iodide is itself a radical scavenger... 

Table III. Effect of Cyclopropane on the Methyl Radical Yield from Methyl Chloride Solutions in Cyclohexane0...

One further comment can be made. The hydrogen yield observed for cyclohexane solutions 0.1 M in CH3I is 2.5 (65). This is lower (by 0.8) than the yield observed at similar concentrations of other electron scavengers (Figure 3). The total G(H2) + G(CH 3) 1 Gr(CH4)UnRcaveiiKeabl equals 6.0 which can be compared with the slightly lower totals indicated in Table IV for methyl chloride solutions. Thus, while studies of the effect of methyl iodide on the positive-ion reactions of cyclopropane indicate that the methyl iodide does undergo positive-ion reactions, these reactions do not seem to make more than a relatively minor contribution (possibly — 0.4) to the products under discussion. 

High-molecular-weight polyisobutylene (PIB) is produced by cationic chain polymerization in methyl chloride solution at — 70°C using aluminum chloride as the catalyst. Such polymers are currently available from Esso (Vistanex) and BASF (Oppanol). 

With the Al(CH3)3/t-C4H9Q system, polymerization of isobutylene occurs in methyl chloride solution but not in n-pentane. Methyl chloride may be considered as being a co-coinitiator in profoundly... 

Table 3. Synthesis of various hydrocarbons by reactitm of alkyl and aralkyl chlorides with A1 (CH3)3 in methyl chloride solution (28)...

Chandrasekhar, J., Smith, S,F,m Jorgensen, W.L. Theoretical examonation of the Stv2 reaction involving chloride ion and methyl chloride in the gas phase and aqueous solution. J. Amer. Chem. Soc. 107 (1985) 154-163. 

Figure 5.21 reprinted with permission from Chandrasekhar J, S F Smith and W L Jorgensen. Theoretical Examination of the 5 2 Reaction Involving Chloride Ion and Methyl Chloride in the Gas Phase and Aqueous Solution. The Journal of the American Chemical Society 107 154-163. 1985 American Chemical Society. 

Meanwhile add 4 drops of methyl-red and 1 ml. of 10% ammonium chloride solution to B. The colour will normally be yellow if so, add A//10 HCl from Bh drop by drop, until a red colour is just obtained. 

Separate the ketone layer from the water, and redistil the lattCT rmtil about one third of the material has passed over. Remove the ketone after salting out any dissolved ketone with potassium carbonate (5). Wash the combined ketone fractions four times with one third the volume of 35-40 per cent, calcium chloride solution in order to remove the alcohol. Dry over 15 g. of anhydrous calcium chloride it is best to shake in a separatory funnel with 1-2 g. of the anhydrous calcium chloride, remove the saturated solution of calcium chloride as formed, and then allow to stand over 10 g. of calcium chloride in a dry flask. Filter and distil. Collect the methyl n-butyl ketone at 126-128°. The yield is 71 g. 

Reaction of hexamethylbenzene with methyl chloride and aluminum chlonde gave a salt A which on being treated with aqueous sodium bicarbonate solution yielded compound B Suggest a mechanism for the conversion of hexamethylbenzene to B by correctly infemng the structure of A... 

Anhydrous stannous chloride, a water-soluble white soHd, is the most economical source of stannous tin and is especially important in redox and plating reactions. Preparation of the anhydrous salt may be by direct reaction of chlorine and molten tin, heating tin in hydrogen chloride gas, or reducing stannic chloride solution with tin metal, followed by dehydration. It is soluble in a number of organic solvents (g/100 g solvent at 23°C) acetone 42.7, ethyl alcohol 54.4, methyl isobutyl carbinol 10.45, isopropyl alcohol 9.61, methyl ethyl ketone 9.43 isoamyl acetate 3.76, diethyl ether 0.49, and mineral spirits 0.03 it is insoluble in petroleum naphtha and xylene (2). 

In the initial thiocyanate-complex Hquid—Hquid extraction process (42,43), the thiocyanate complexes of hafnium and zirconium were extracted with ether from a dilute sulfuric acid solution of zirconium and hafnium to obtain hafnium. This process was modified in 1949—1950 by an Oak Ridge team and is stiH used in the United States. A solution of thiocyanic acid in methyl isobutyl ketone (MIBK) is used to extract hafnium preferentially from a concentrated zirconium—hafnium oxide chloride solution which also contains thiocyanic acid. The separated metals are recovered by precipitation as basic zirconium sulfate and hydrous hafnium oxide, respectively, and calcined to the oxide (44,45). This process is used by Teledyne Wah Chang Albany Corporation and Western Zirconium Division of Westinghouse, and was used by Carbomndum Metals Company, Reactive Metals Inc., AMAX Specialty Metals, Toyo Zirconium in Japan, and Pechiney Ugine Kuhlmann in France. 

Dry methyl chloride is unteactive with all common metals except the alkaU and alkaline-earth metals, magnesium, 2iac, and alumiaum. In dry ether solution, methyl chloride reacts with sodium to yield ethane by the Wurt2 synthesis ... 

Methyl chloride can be converted iato methyl iodide or bromide by refluxing ia acetone solution ia the presence of sodium iodide or bromide. The reactivity of methyl chloride and other aUphatic chlorides ia substitution reactions can often be iacteased by usiag a small amount of sodium or potassium iodide as ia the formation of methyl aryl ethers. Methyl chloride and potassium phthalimide do not readily react to give /V-methy1phtha1imide unless potassium iodide is added. The reaction to form methylceUulose and the Williamson synthesis to give methyl ethers are cataly2ed by small quantities of sodium or potassium iodide. 

Methyl chloride reacts with ammonia alcohoHc solution or ia the vapor phase by the Hofmann reaction to form a mixture of the hydrochlorides of methylamine, dimethylamine, trimethyl amine, and tetramethyl ammonium chloride. With tertiary amines, methyl chloride forms quaternary derivatives. 

There is no specific color or other reaction by which methyl chloride can be detected or identified. QuaUty testing of methyl chloride for appearance, water content, acidity, nonvolatile residue, residual odor, methanol, and acetone is routinely done by production laboratories. Water content is determined with Kad Fischer reagent using the apparatus by Kieselbach (55). Acidity is determined by titration with alcohoHc sodium hydroxide solution. The nonvolatile residue, consisting of oil or waxy material, is determined by evaporating a sample of the methyl chloride at room temperature. The residue is examined after evaporation for the presence of odor. Methanol and acetone content are determined by gas chromatography. 

The sodium carbonate content may be deterrnined on the same sample after a slight excess of silver nitrate has been added. An excess of barium chloride solution is added and, after the barium carbonate has setded, it is filtered, washed, and decomposed by boiling with an excess of standard hydrochloric acid. The excess of acid is then titrated with standard sodium hydroxide solution, using methyl red as indicator, and the sodium carbonate content is calculated. 

Relationships connecting stmcture and properties of primary alkylamines of normal stmcture C, -C gin chloroform and other solvents with their ability to extract Rh(III) and Ru(III) HCA from chloride solutions have been studied. The out-sphere mechanism of extraction and composition of extracted associates has been ascertained by UV-VIS-, IR-, and H-NMR spectroscopy, saturation method, and analysis of organic phase. Tertiary alkylamines i.e. tri-n-octylamine, tribenzylamine do not extract Ru(III) and Rh(III) HCA. The decrease of radical volume of tertiary alkylamines by changing of two alkyl radicals to methyl make it possible to diminish steric effects and to use tertiary alkylamines with different radicals such as dimethyl-n-dodecylamine which has not been used previously for the extraction of Rh(III), Ru(III) HCA with localized charge. 

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