Tetrachloromethane conductivity

Scheme 5.6). The reaction can be conducted under basic liquidiliquid conditions but, in order to minimize hydrolysis of the phosphite and to prevent carbene formation, a milder solid (KHCO, liquid system with tetra-/i-butyIammonium bromide is preferred. Under these conditions, yields are almost quantitative [38]. Tetra-bromomethane is generally recommended, in preference to tetrachloromethane, for reactions with weakly basic aryl-amines. 

Prengle et al. (1996) studied the photooxidation by UV/H202 of waterborne hazardous Q-Q compounds in drinking water. Their work was conducted in a photochemical batch stirred-tank reactor, with medium pressure mercury arc immersion lamps of 100 and 450 W, covering the visible UV range, (578.0 to 222.4 nm). Tetrachloromethane, tetrachloroethane, dichloro-ethane, dichloroethene, trichloroethane, trichloroethene, and benzene were the compounds studied. Dark oxidation rates and photooxidation rates were determined. The latter rate constants were 104 to 10s greater than those under dark conditions. 

A further useful application of SC-CO2 as a reaction medium is the free-radical side-chain bromination of alkylaromatics, replacing conventional solvents such as tetra-chloromethane or chlorofluorohydrocarbons having no abstractable hydrogen atoms [920]. For example, bromination of ethylbenzene in SC-CO2 at 40 °C and 22.9 MPa yields 95 cmol/mol (1-bromoethyl)benzene, with practically the same regioselectivity as obtained in conventional tetrachloromethane as the solvent. Even the classical Wohl-Ziegler bromination of benzylic or allylic substrates using A-bromosuccinimide (NBS) can be conducted in SC-CO2 [920]. Irradiation of a solution of toluene, NBS, and AIBN (as initiator) in SC-CO2 at 40 °C and 17.0 MPa for 4 hours gave (bromomethyl)-... 

For instance, polyacetylene that has been produced in silicone oil with a specially treated catalyst shows surprisingly high conductivities after being doped with iodine (tetrachloromethane saturated with iodine at 25 C). 

FIGURE 8.29 UV-Vis-NIR spectra of PPy-DBSA films cast from the solutions in (a) chloroform, (b) chlorobenzene, and (c) tetrachloromethane containing extra DBSA which is removed by washing after evaporation of the solvent. (From Song, K.T., Synthesis of electrically conducting soluble polypyrrole and its characterization. Ph.D. thesis, 2000. With permission.)... 

The rate data in radiation-induced bulk polymerization of vinyl fluoride revealed a heterophase process.Polymerization was conducted aty-ray dosage rates of 13-100 rad/s using Co. The rate of polymerization at 3 8°C was proportional to the dosage rate to the power 0.42. Gas-phase polymerization of VF with y-rays has been studied in the range of 10-100 rad/s. Polymerization rate increased sharply with the increase in dosage, leading to generation of active sites in the polymer chain and branches. Radiation polymerization of vinyl fluoride dissolved in solvents such as tetrachloromethane lead to chain transfer and incorporation of solvent in the polymer. Vinyl fluoride can also be polymerized in plasma. 

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