Aqueous methane

The decanted aqueous phase was extracted three times with a total of 150 ml of ethyl acetate. The combined organic solutions were filtered over Clarcel and extracted three times with a total of 150 ml of an Iced normal aqueous methane-sulfonic acid solution. The combined acid extracts were rendered alkaline on an ice bath with 30 ml of ION caustic soda solution. The separated oil was extracted four times with a total of 200 ml of ether. The combined ethereal extracts were washed twelve times with a totai of 360 ml of distilled water, dried over anhydrous magnesium sulfate in the presence of 0.3 g of animal charcoal and evaporated under reduced pressure on a water bath at 40°C. The oily residue obtained (3.8 g) was dissolved in 30 ml of boiling acetonitrile. After cooling for 2 hours at 3°C, the crystals formed were separated, washed with 5 ml of acetonitrile and dried at ambient temperature at low pressure. 

Fig. 10. Solubility of Ce(III/IV) in aqueous methane sulfonic acid and sulfuric acid. [132], cf also Ref. [134, 135]...

There are only few data sets of aqueous solubility for systems with hydrates (1) methane and ethane solubility in water as a function of temperature ramping rate (Song et al. 1997), (2) carbon dioxide solubility in water by Yamane and Aya (1995), (3) methane in water and in seawater (Besnard et al., 1997), (4) methane in water in Lw-H region [see Servio and Englezos (2002) and Chou and Burruss, Personal Communication, December 18,2006, Chapter 6], As a standard for comparison, Handa s (1990) calculations for aqueous methane solubility are reported in Table 4.3. 

Ravishanker G, Mezei M, Beveridge DL (1982) Monte Carlo simulation study of the hydro-phobic effect. Potential of mean force for aqueous methane dimer at 25 and 50 °C. Farad Symp Chem Soc 17 79-91... 

Among electron carriers used for indirect oxidation reactions, cerium salts [Ce -t- e Ce E° = -t-1.44 V vs. NHE] appear to be of particular interest when a mild oxidation has to be considered. Substituted toluenes and methylaryl compounds are easily functionalized to the corresponding aldehydes in high yields [125-129]. Acidic solutions are required (such as aqueous AcOH, aqueous methane sulfonic acid, or aqueous trifluorosulfonic acid). The conversion of aromatic compounds into quinones may also be conducted by means of electrogenerated ceric ions (see Table 3). Let us stress the example... 

Dimethyl-6-hydroxy-3,6-dihydro-2/f-l,3,4-oxadiazine (309), a cyclic hemiacetal, is formed by reaction of 2-methylhydrazonopropanal (MeNHN=C(Me)CHO) with aqueous methanal <85JCS(P1)81>. 

A y-ray and electron-pulse radiolytic study of aqueous methane has been effected. The absorption spectrum of the methyl free radical has been measured in the range 210—270 nm [at 210 nm, (CH8) = 8501 mol" cmr ), and by determining its rates of formation and decay the rate constants for the reactions ... 

Lin, C. L. and R. H. Wood. 1996. Prediction of the free energy of dilute aqueous methane, ethane, and propane at temperatures from 600 to 1200 degrees C and densities from 0 to 1 g cm using molecular dynamics simulations. Journal of Physical Chemistry. 100, 16399. 

It should be emphasized here that hydrophobic hydration shells are quite voluminous. Computer simulations can be used for estimating hydration numbers. For example, Jorgensen has reported hydration numbers of 20 and 34 for, respectively, methane and n-pentane. A C-NMR study gave a hydration number of 20 for aqueous methane. 

Although many problems still remain to be overcome to make the process practical (not the least of which is the question of the corrosive nature of aqueous HBr and the minimization of formation of any higher brominated methanes), the selective conversion of methane to methyl alcohol without going through syn-gas has promise. Furthermore, the process could be operated in relatively low-capital-demand-ing plants (in contrast to syn-gas production) and in practically any location, making transportation of natural gas from less accessible locations in the form of convenient liquid methyl alcohol possible. 

Under these first-order conditions the rates of nitration of a number of compounds with acetyl nitrate in acetic anhydride have been determined. The data show that the rates of nitration of compounds bearing activating substituents reach a limit by analogy with the similar phenomenon shown in nitration in aqueous sulphuric and perchloric acids ( 2.5) and in solutions of nitric acid in sulpholan and nitro-methane ( 3.3), this limit has been taken to be the rate of encounter of the nitrating entity with the aromatic molecule. 

Most of the HCl produced is consumed captively, ie, at the site of production, either in integrated operations such as ethylenedichloride—vinyl chloride monomer (EDC/VCM) plants and chlorinated methane plants or in separate HCl consuming operations at the same location. Captive use of anhydrous HCl accounted for 80—85% of the total demand in 1989. The combined merchant market for anhydrous and aqueous HCl in that same year was about 9.1 X 10 metric tons on the basis of 100% HCl (see Table 12) (73). 

On dehydration, nitro alcohols yield nitro-olefins. The ester of the nitro alcohol is treated with caustic or is refluxed with a reagent, eg, phthaUc anhydride or phosphoms pentoxide. A mil der method involves the use of methane sulfonyl chloride to transform the hydroxyl into a better leaving group. Yields up to 80% after a reaction time of 15 min at 0°C have been reported (5). In aqueous solution, nitro alcohols decompose at pH 7.0 with the formation of formaldehyde. One mole of formaldehyde is released per mole of monohydric nitro alcohol, and two moles of formaldehyde are released by the nitrodiols. However, 2-hydroxymethyl-2-nitro-l,3-propanediol gives only two moles of formaldehyde instead of the expected three moles. The rate of release of formaldehyde increases with the pH or the temperature or both. 

Methylene chloride is easily reduced to methyl chloride and methane by alkaU metal ammonium compounds in Hquid ammonia. When the vapor is contacted with reduced nickel at 200°C in the presence of excess hydrogen, hydrogen chloride and elementary carbon are produced. Heating with alcohoHc ammonia at 100—125°C results in hexamethylenetetramine, (CH2) N4, a heterocycHc compound with aqueous ammonia at 200°C, hydrogen chloride, formic acid, and methylamine are produced. 

Chloroform can be reduced to methane with 2inc dust and aqueous alcohol. In the presence of a catalyst or ammonia, the reduction yields methylene chloride as well as methane. 

Oxychlorination of Hydrocarbons. Methane was oxychlorinated with HCl and oxygen over a 4 3 3 CuCl—CUCI2—KCl molten mixture to give a mixture of chlorinated methanes, 60 mol % of which was carbon tetrachloride (28). Aqueous 20% HCl was used in the multistep process as the source of the acid. Anhydrous HCl is more typically used. Other oxychlorination processes can be made to yield high percentages of carbon tetrachloride starting from any of several hydrocarbon feeds (29—31). The typical reaction temperature is 400—600°C (see Chlorocarbons and chlorohydrocarbons. Methyl cm oRiDE Methylene cphoride and Cphoroform). 

An aiyl methane- or toluenesulfonate ester is stable to reduction with lithium aluminum hydride, to the acidic conditions used for nitration of an aromatic ring (HNO3/HOAC), and to the high temperatures (200-250°) of an Ullman reaction. Aiyl sulfonate esters, formed by reaction of a phenol with a sulfonyl chloride in pyridine or aqueous sodium hydroxide, are cleaved by warming in aqueous sodium hydroxide. ... 

Ferrocene (46.4 g., 0.250 mole) (Note 1) is added to a well-stirred solution of 43.2 g. (0.422 mole) of bis(dimethylamino)-methane (Note 2) and 43.2 g. of phosphoric acid in 400 ml. of acetic acid in a 2-1. three-necked round-bottomed flask equipped with a condenser, a nitrogen inlet, and a mechanical stirrer (Note 3). The resulting suspension is heated on a steam bath under a slow stream of nitrogen (Note 4) for 5 hours (Note 5). The reaction mixture, a dark-amber solution, is allowed to cool to room temperature and is diluted with 550 ml. of water. The unreacted ferrocene is removed by extracting the solution with three 325-ml. jiortions of ether. The aqueous solution is then looled in ice water and made alkaline by the addition of 245 g. 

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