Carbon tetrachloride basicity

Stannic Chloride. Stannic chloride is available commercially as anhydrous stannic chloride, SnCl (tin(IV) chloride) stannic chloride pentahydrate, SnCl 5H20 and in proprietary solutions for special appHcations. Anhydrous stannic chloride, a colorless Aiming Hquid, fumes only in moist air, with the subsequent hydrolysis producing finely divided hydrated tin oxide or basic chloride. It is soluble in water, carbon tetrachloride, benzene, toluene, kerosene, gasoline, methanol, and many other organic solvents. With water, it forms a number of hydrates, of which the most important is the pentahydrate. Although stannic chloride is an almost perfect electrical insulator, traces of water make it a weak conductor. 

The relative basicity of carbonyl oxygen atoms can be measured by studying strength of hydrogen bonding between the carbonyl compound and a hydrogen donor such as phenol. In carbon tetrachloride, values of for 1 1 complex formation for the compounds shown have been measured. Rationalize the observed order of basicity. 

C <4.7x10 Pa at 20 °C Water 20 mg at 20 °C Readily soluble in polar organic solvents Stable in neutral and weakly basic conditions Unstable in strongly acidic or basic conditions Stable in most of organic solvents such as acetone, acetonitrile and carbon tetrachloride Undergoes hydrolysis to yield methomyl oxime in alkaline solutions... 

Similar treatment of a trifluoroacetic acid solution of p-tolualdehyde with triethylsilane gives only a 20% yield of /7-xylene after 11 hours reaction time followed by basic workup. Use of 2.5 equivalents of dimethylphenylsilane enhances the yield to 52% after only 15 minutes. This reaction proceeds stepwise through the formation of a mixture of the trifluoroacetate and the symmetrical ether. These intermediates slowly form the desired /7-xylene product along with Friedel-Crafts side products under the reaction conditions (Eq. 192).73 Addition of co-solvents such as carbon tetrachloride or nitromethane helps reduce the amount of the Friedel-Crafts side products.73... 

Properties of the carbonyl group of ferrocenyl germyl ketones (15) were studied by IR, NMR and XRD. The carbonyl basicity was assessed based on hydrogen bonding with phenol in carbon tetrachloride solution (see also Tables 2 and 3). The spectra were compared with those of the analogous Si compounds and those of acetyl- and benzoylgermanes54. 

Amino groups may act not only as proton acceptor, but also as proton donor. Acidic N—H protons interact with basic solvents. In these cases an ortho-nitro group in an aniline system competes with the solvent by an internal hydrogen bond66, as depicted in 12. The stretching frequencies (by IR spectra in carbon tetrachloride) of vnh of complexes between A-methylaniline or diphenylamine (and some nitro-anilines66) and solvents depend on the proton accepting ability of the solvent (which is a moderate base)67. The frequency shifts are linearly related to the solvent s donor number (DN)3. 

Recently195, the hydrogen bond basicity scale (p.K hb as logarithm of the formation constant of 4-fluorophenol/base complexes in carbon tetrachloride, equilibrium 21) has been measured for several nitro derivatives (nitromethane, nitrobenzene, IV-nitrocamphorimine, 2-nitropropane, 4-nitro-o-xylene, 4-nitroanisole, lV,./V-diethyl-4-nitroaniline, l-dimethylamino-2-nitroethylene, l-piperidino-2-nitroethylene) ... 

In an interesting catalysed conversion of trichloroethene by secondary amines into aminoacetamides, the initial steps are thought to involve the p-elimination of HC1 to produce dichloroethyne (Scheme 9.1), which reacts with the secondary amine under the wet conditions to produce the amide [35] the reaction does not work with N-alkylanilines. Such a mechanism is realistic, as it is well known [36] that trichloroethene is converted into the inflammable and explosive dichloroethyne by bases, and quaternary ammonium salts catalyse the formation of the alkyne when trichloroethene is reacted with oxiranes [37]. Chloroethynes have also been obtained by the catalysed reaction of terminal ethynes with carbon tetrachloride under basic conditions [38]. 

In the case of halogen substitution the values of von he between those for benzene and carbon tetrachloride, i.e. the basicity of the aromatic substances, which is to be regarded as responsible for the formation of this TT-complex, decreases with halogen-substitution. These conclusions had already been deduced by Liittke and Mecke (1949) from their measurements. 

The hepatotoxic effects of carbon tetrachloride have been widely studied in animals. Indeed, carbon tetrachloride is used as a model chemical in many laboratory investigations of the basic mechanism of action of hepatotoxic chemicals. Oral exposure to carbon tetrachloride has been observed to result in a wide spectrum of adverse effects on the liver, the most prominent of which are destruction of the smooth and rough endoplasmic reticulum and its associated enzyme activities (Reynolds and Yee 1968), inhibition of protein synthesis (Lutz and Shires 1978), impaired secretion of triglycerides with resultant fat accumulation (Fischer-Nielsen et al. 1991 Recknagel and Ghoshal 1966 Recknagel and Glende 1973 Waterfield et al. 1991), centrilobular necrosis (Blair et al. 1991 Reynolds and Yee 1968 Waterfield et al. 1991 Waterfield et al. 1991 Weber et al. 1992), and eventually fibrosis and cirrhosis (Allis et al. 1990 Bruckner et al. 1986 Fischer-Nielsen et al. 1991 Weber etal. 1992). 

It is desirable to have means to measure organohalides such as carbon tetrachloride in situ in water and other environmental media. One approach to doing this has been demonstrated by the in situ analysis of chloroform-contaminated well water using remote fiber fluorimetry (RFF) and fiber optic chemical sensors (FOGS) (Milanovich 1986). With this approach, fluorescence of basic pyridine in the presence of an organohalide (Fujiwara reaction) is measured from a chemical sensor immersed in the water at the end of an optical fiber. Carbon tetrachloride undergoes a Fujiwara reaction, so its determination might be amenable to this approach. 

In the case of naphthalene, transitions to the two lowest excited states (again, often indicated with Lb and La) are two-photon forbidden, as in benzene. However, due to vibronic coupling, the Lb band is visible in the 2PA spectrum of naphthalene in the 575-650 nm region (see Fig. 5), while La gains intensity in the IPA spectrum and peaks around 275 nm [44-46], but is basically absent from the 2PA spectrum this is again in line with predictions based on the pseudoparity of the states. Polarization ratio data were used to aid the band assignment. A weak 0-0 peak of the Lb band can actually be seen in the 2PA spectrum (at 630.5 nm for naphthalene in cyclohexane [45] and at 631.8 nm in carbon tetrachloride [47]), probably because of local perturbation of the symmetry due to the solvent environment or other effects [44,45]. The 2PA... 

The compound is produced by evaporating hydrochloric acid solutions of polonium (IV) 6, 26, 74), by heating the dioxide in carbon tetrachloride vapor 74), in hydrogen chloride, thionyl chloride or with phosphorus pentachloride 6) and by heating the metal in dry chlorine at 200°C (6, 25, 74). It is hygroscopic and hydrolyzes in moist air to a white solid, possibly a basic chloride (7)). The tetrachloride is soluble in thionyl chloride and in water with hydrolysis, and is moderately soluble in ethanol, acetone, and... 

Figure 2 shows the positions of the N—H bands for various amines in carbon tetrachloride (as giving the frequency of the free N—II vibration) and in acetone (giving the bonded N—H frequency). Fig. S shows the frequencies in carbon tetrachloride and in pyridine. The amines are arranged in descending order of decreasing basicity, so far... 

In this chapter experimental approach to the study of a photochemical reaction is gradually developed starting from simple observations. It is expected that such an approach will promote basic understanding of the methodology and an appreciation for the use of sophisticated instruments necessary in photochemical studies. The case history of the reaction be tween anthracene and carbon tetrachloride has been taken up as this apparently simple reaction has many complexities and has been investigated bv a number of workers at various levels of sophistication. 

In an ESR study of the interaction of oxovanadium(IV) cupferronate with basic organic solvents, it has been shown that the coordination of basic solvent molecules leads to the destruction of the dimeric nature of the complex molecules.109 Parameters of the spin Hamiltonian of the ESR spectra of the adducts thus formed in 15 cases have been correlated with the basicity of the organic solvents. By contrast, VO(cupferronate)2 retains its diamagnetic dimeric form in the frozen solution of non-coordinating solvents such as chloroform, carbon tetrachloride, cyclohexane or benzene. 

Di-m-tolyl tellurium dichloride, (CH3.C6H4)2TeCl2,3 is formed when di-m-tolyl telluride in ether solution is chlorinated. The product appears as needles, sintering at 128° C. and melting at 131° to 132° C., readily soluble at the ordinary temperature in benzene, toluene, xylene, carbon disulphide, chloroform or carbon tetrachloride, less soluble in methyl or ethyl alcohol, insoluble in petroleum. When the dichloride is boiled with water a white powder separates on cooling this melts at 87° C. to a viscous oil which gradually becomes watery. Analysis shows this product to be a basic salt and not the anhydride. 

---