Carbon tetrachloride CAS

The decolonization of the yellow product (Note 11) is achieved by dissolving the product in an equal volume of carbon tetrachloride (ca. 12 ml.) and vigorously shaking the solution thus obtained with 1.5 ml. of a freshly prepared aqueous 35% sodium thiosulfate. The two layers are completely separated after 5 minutes. The colorless bottom layer is drawn off into a 50-ml. Erlenmeyer flask. The top layer is extracted three times with 1.5 ml. of carbon tetrachloride. The combined carbon tetrachloride solution is dried over 0.5 g. (Note 12) of anhydrous magnesium sulfate for 30 minutes. The solution is then filtered into a 50-ml. distilling flask, and the magnesium sulfate is washed several times with carbon tetrachloride (total 5 ml.). The solvent is removed, and the colorless product is distilled as described above, affording 14.7-15.8 g. (69-74% overall, based on hexanoic acid 88-92% for the decolonization step) of colorless 2-bromohexanoyl chloride, b.p. 45-47° (1.5 mm.), n22 d 1.4706 (Note 13), i 4 1.4017 (Notes 14 and 15). 

CARBON TETRACHLORIDE. [CAS 56-23-5], CCL, formula weight 82.82. heavy, colorless, nonflammable, noncombustible liquid, nip - 23°C. bp 76.75 C. sp gr 1.588 <2S C/25lC). vapor density 5.32 (air = 1.00). critical temperature 283.2cC. critical pressure 661 atmospheres, solubility 0.08 g in 100 g H 0. odor threshold 80 ppm. Dry carbon tetrachloride is noncorrosive to common metals except aluminum. When wet. CCL hydrolyzes and is corrosive to iron, copper, nickel, and alloys containing those elements About 9091 of all CCL manufactured goes into the production of chlorofluorocarbons ... 

Spektr T.T.T. http //www.spektr-ttt.ru Carbon tetrachloride CAS 56-23-5 EINECS/ELINCS 200-262-8 UN 1846 (DOT)... 

A chemical that does not ignite, does not bum, or is extremely difficult to bum. Example carbon tetrachloride, CAS 56-23-5... 

Manufacture. Phosphoms pentachloride is manufactured by either batch or continuous processing. In the former, the phosphoms trichloride usually dissolves in carbon tetrachloride before being treated with chlorine. A mixture of ca one part of phosphoms trichloride to one part of carbon tetrachloride is introduced to a water-jacketed vessel that contains an efficient stirrer and a tight cover with a redux condenser. The chlorine is passed into the vessel below the Hquid level, and crystals of phosphoms pentachloride form in the Hquid. When the reaction is completed, the suspension of crystals of phosphoms pentachloride in the carbon tetrachloride is drawn out of the vessel and the crystals are filtered and then dried by circulating hot water through the jacket of the filter. The clarified carbon tetrachloride is returned to the reaction vessel. 

Bulk polymerization has been studied at relatively low temperatures and in toluene and carbon tetrachloride solutions carried to low conversions (12). The effects of temperature and different organic peroxide initiators have been observed. The molecular weight of soluble polymer after 3% conversion is ca — 19,000 and is somewhat dependent on initiator concentration or temperature between 35 and 65 °C. With di-2-methylpentanoyl... 

Styrene is a colorless Hquid with an aromatic odor. Important physical properties of styrene are shown in Table 1 (1). Styrene is infinitely soluble in acetone, carbon tetrachloride, benzene, ether, / -heptane, and ethanol. Nearly all of the commercial styrene is consumed in polymerization and copolymerization processes. Common methods in plastics technology such as mass, suspension, solution, and emulsion polymerization can be used to manufacture polystyrene and styrene copolymers with different physical characteristics, but processes relating to the first two methods account for most of the styrene polymers currendy (ca 1996) being manufactured (2—8). Polymerization generally takes place by free-radical reactions initiated thermally or catalyticaHy. Polymerization occurs slowly even at ambient temperatures. It can be retarded by inhibitors. 

Halides and Oxyhalides. Vanadium(V) oxytrichloride is prepared by chloriaation of V20 mixed with charcoal at red heat. The tetrachloride (VCl is prepared by chlorinating cmde metal at 300°C and freeing the Hquid from dissolved chlorine by repeated freezing and evacuation. It now is made by chlorinating V20 or VOCl ia the presence of carbon at ca 800°C. Vanadium trichloride (VCl ) can be prepared by heating VCl ia a stream of CO2 or by reaction of vanadium metal with HCl. 

As chlorination proceeds from methyl chloride to carbon tetrachloride, the length of the C—Cl bond is decreased from 0.1786 nm in the former to 0.1755 nm in the latter (3). At ca 400°C, thermal decomposition of carbon tetrachloride occurs very slowly, whereas at 900—1300°C dissociation is extensive, forming perchloroethylene and hexachloroethane and Hberating some chlorine. Subjecting the vapor to an electric arc also forms perchloroethylene and hexachloroethane, as well as hexachlorobenzene, elementary carbon, and chlorine. 

Other options for the purification of CA include dissolution in hot water, aqueous ammonia, aqueous formaldehyde, or hot dimethylformamide followed by filtration to remove most of the impurities. The CA is recoverable by cooling the aqueous solution (84), acidifying the ammonium hydroxide solution (85), or cooling the dimethylform amide solution with further precipitation of CA by addition of carbon tetrachloride (86). Sodium hydroxide addition precipitates monosodium cyanurate from the formaldehyde solution (87). 

Medium Boiling Esters. Esterificatioa of ethyl and propyl alcohols, ethylene glycol, and glycerol with various acids, eg, chloro- or bromoacetic, or pymvic, by the use of a third component such as bensene, toluene, hexane, cyclohexane, or carbon tetrachloride to remove the water produced is quite common. Bensene has been used as a co-solvent ia the preparatioa of methyl pymvate from pymvic acid (101). The preparatioa of ethyl lactate is described as an example of the general procedure (102). A mixture of 1 mol 80% lactic acid and 2.3 mol 95% ethyl alcohol is added to a volume of benzene equal to half that of the alcohol (ca 43 mL), and the resulting mixture is refluxed for several hours. When distilled, the overhead condensate separates iato layers. The lower layer is extracted to recover the benzene and alcohol, and the water is discarded. The upper layer is returned to the column for reflux. After all the water is removed from the reaction mixture, the excess of alcohol and benzene is removed by distillation, and the ester is fractionated to isolate the pure ester. 

Isolation of the pure a,0 -ieomer, A 250-mL Erlenmeyer flask equipped with a magnetic stirring bar is charged with the isomeric nitriles (20 g, 0.165 mol), prepared in Part A above, and carbon tetrachloride (20 mL). A solution of bromine in carbon tetrachloride (1/9, v/v, ca. 25-30 mL) is added dropwise until the color of excess bromine persists. The reaction vessel is cooled in an ice bath for 30 min, filtered by gravity and the solvent evaporated under reduced pressure. The crude oil is distilled at reduced pressure (bp 40-42 0/0,15 mm) to give a colorless liquid (11-15 g, 55-75%) which is the pure a.p-1somer (Notes 9 and 10). 

The flask is removed from the oil bath and cooled to room temperature. To the reaction mixture are added successively 21.4 g. (0.12 mole) of finely powdered Nduomosuccininiide (l-bromo-2,5-pyrrolidinedione) (Note 4), 50 ml. of carbon tetrachloride, and 7 drops of aqueous 48% hydrogen bromide (Note 5). The flask is heated at 70 for 10 minutes (Note 6), and the temperature of the bath is then increased to 85° until the color of the reaction becomes light yellow (ca. 1.5 hours Note 7). The reaction mixture is cooled to room temperature, and the carbon tetrachloride and excess thionyl chloride are removed under reduced pressure (Note 8). The residue is suction filtered, and the solid (Note 9) is washed several times with carbon tetrachloride (total 20 ml.) and the combined filtrate collected in a 50-rnl. flask. The solvent is removed from the solution as before, and the residue is distilled into a dry ice-cooled receiver (short-path column) to give, after a small forerun, 16.1-17.1 g. (76-80%) of 2-bromohexanoyl chloride, b.p. 44-47 (1.5 mm.) as a clear, slightly yellow oil, n12 d 1.4707. This material is of sufficient purity for most synthetic purposes (Note 10). 

All of the samples analyzed were standard one-inch diameter polished thin sections. Whenever feasible the samples received a final, cleansing polish with 1 pm diamond compound made from commercial graded diamonds embedded in "vaseline". Commercial diamond paste has proved unsatisfactory due to high levels of K, Na, Cl, Si, F, and Ca. Samples are then cleaned with carbon tetrachloride, rinsed in ethanol, and coated with vacuum evaporator. This sample preparation technique was developed during our studies of minor elements [16,17] and has proved to produce consistently contamination-free samples. 

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