Benzene-chloroform complex

The CH/tt interaction is very weak in most cases. The interaction energies of benzene complexes with methane, ethane and ethylene are around -2 kcal/mol, as summarized in Table 6. The attraction is enhanced when electronegative substituents (chlorine and fluorine atoms) are attached to the carbon atom of the C - H bond [112]. The interaction energy of the benzene-chloroform complex (- 5.6 kcal/mol) is considerably greater than that of the benzene-methane complex (- 1.5 kcal/mol). The enhancement of the attraction was explained by the increased electrostatic interaction. The substituent increases the positive charge on the hydrogen atom of the C - H bond and thereby increases the attractive electrostatic interaction. The electrostatic energy in the benzene-chloroform complex (- 2.4 kcal/mol) is 2.2 kcal/mol... 

In a paper recently published 2>, we point out that, except for a bromine-benzene complex studied by Duchesne, the results reported in the literature do not offer any clear evidence for charge transfer. A systematic observation of both nitrogen and chlorine resonances in some complexes led us to admit the existence of a small transfer (0.05 electron) in chloroform complexes with amines and pyridine derivatives. Though the number of compounds studied is still small, the observed effects are not thought to be due to mere coincidence, and it appears very desirable to extend such experiments especially for stronger complexes. 

Dinitrogen trioxide-Boron trifluoride, NjOs-BF.,. The components react at —70 to form a stable white 1 1 complex. It is a weak nitrating agent but a powerful diazo-tizing agent in nonaqueous solution (benzene, chloroform). The diazonium salt which separates as a solid can be thermally decomposed to form fluoro derivatives (Schiemann reaction) or used in Gomberg-Bachmann arylation. 

Both complexes precipitate as extremely minute crystals. The olive-green mono(dipyridylamine) complex is stable in air up to a temperature of 290°, whereas the bis(dipyridyl-amine) complex is stable up to 235°. Both compounds are very slightly soluble in acetone, ethyl ether, benzene, chloroform, and carbon tetrachloride. The mono(dipyri-... 

Di-/i-chlorotetrakis(cyclooctene)diiridium(I) is an air-sensitive yellow solid. Upon exposure to air, it readily decomposes to a dark-green solid which eventually blackens. It is soluble in benzene, chloroform, and acetone solutions in these solvents are extremely sensitive to oxygen. The complex may be stored for a prolonged period of time in vacuo in a vacuum desiccator. Other physical properties of the complex are given in the literature.5... 

The complex is moderately soluble in benzene, chloroform, and dichloromethane. 

Hydridotetrakis(triphenylphosphine)rhodium(I) forms yellow microcrystals which melt at 145-147° in air and at 154—156° in a capillary sealed under nitrogen. The infrared spectrum shows a band at 2156 (m) cm.-1 attributable to v(RhH). The complex is soluble in benzene, chloroform, and dichloromethane. 

This section has thus presented a quick synthesis and analysis method for two simplified infinite reflux cases. Just like simple columns, it can be generally stated that if a design is considered feasible at infinite reflux conditions, then a feasible design can be found at finite reflux too. This fact is particularly useful for nonideal systems. An illustration of a more complex infinite Petlyuk column example is given in the following example for the azeotropic acetone/benzene/chloroform system. 

Blake and Kubota have convincingly shown that in anhydrous benzene, chloroform and ether, as in the gaseous reaction on the solid complex, hydrogen halides (HX) and /m -[Iry(CO)(PPh3)2] (T = halogen) react to give octahedral cw-addition products (i.e. H and X cis). In contrast in wet solvents, and in such solvents as dimethylformamide, acetonitrile and ethanol, mixtures of cis and trans products are formed. Whether these solvents cause rapid halide-ion exchange before the addition reaction or in the products is yet to be demonstrated. ... 

The term cotton wax includes all lipids found in the cotton fiber surface, including waxes, fats, and oils [Lawson and Hsieh, 2000 Brushwood, 2003 Bargel et al., 2006]. Cuticular lipids, of cotton, are complex mixtures of aliphatic and aromatic components, most of them resembling derivatives of nacyl alkanes. Benzene, chloroform, carbon tetrachloride, ethanol, isopropyl alcohol, alcohol-benzene mixture, and trichloroethylene have been recommended for extraction of the cotton wax. Lipase activity is often determined with reagents comprising a low concentration... 

Moreover, the copper and nickel complexes substituted by eight dodecyloxy chains displayed lyotropic Ncoi and Colh mesophases in contact preparations with organic solvents (linear alkanes, cyclohexane, benzene, chloroform). The lyomesophases were stable for the copper and nickel complexes, except for the binary mixture between the nickel complex and linear alkane, for which... 

Synonyms Bis (dibutyidithiocarbamato) zinc Carbamic acid, dibutyidithio-, zinc complex Dibutyidithiocarbamic acid zinc salt ZDBC Zinc bibutyidithiocarbamate Zinc bis (dibutylcarbamodithiato-S-S ) Zinc di-n-butyldithiocarbamate Zinc-N,N-dibutyldithiocarbamate Empirical CisH36N2S4Zn Formula Zn[SC(S)N(C4Hg)2]2 Properties Wh. powd., pleasant odor sol. in carbon disulfide, benzene, chloroform insol. in water m.w. 474.13 dens. 1.24 (20/20 C) m.p. 104-108 C... 

FIGURE 10 Examples of hydrogen-bonded compounds where an X-H group attaches o an bond, (a) Complex of chloroform with benzene, (b) Complex of hydrogen chloride with ethylene. 

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