Benzenes dielectric behavior

DIELECTRIC BEHAVIOR OF THE SYSTEM BENZYL CHLORIDE-BENZENE. 

Belaabed, B., Lamouri, S., Naar, N., Bourson, P., and Hamady, S.O.S. (2010) Polyaniline-doped benzene sulfonic add/epoxy resin composites stmctural, morphological, thermal and dielectric behaviors. Polym. J., 42, 546-554. 

Association constant — Solvents having a low dielectric constant (e.g., benzene er = 2.29) cannot split protons from acids. The acid/base behavior in these solvents is based on association reactions between acidic and basic components in the solution according to ... 

The adsorption of Ag(L)2 complex was carried out from its solutions (in benzene, ethanol, dimethylformamide (DMF)) of different composition on the solid s ilicon substrates using the layer-by-layer self-assembling method. Behavior of Ag(L)2 in ethanol and DMF was studied. The physical properties of these solvents, in particular, donor numbers and dielectric constants are rather different [3]. 

Electrochemical methods have played an important role in the recognition of cation radicals as intermediates in organic chemistry and in the study of their properties. An electrode is fundamentally an electron-transfer agent so that, given the proper solvent system, anodic oxidation allows formation of the cation radical without any associated proton or other atom transfer and without the formation of a reduced form in the immediate vicinity of the cation radical. Moreover, because the potential of the electrode can be adjusted precisely, its oxidizing power can be controlled, and further oxidation of the cation radical can often be avoided. Finally, the electrochemical experiment can involve both production of the cation radical and an analysis of its behavior, so that information about the thermodynamics of its formation and the kinetics of its reaction can be obtained, even if the cation radical lifetime is as short as a few milliseconds. There are some limitations, however, in the anodic production of cation radicals. The choice of solvent is limited to those that show reasonable conductivity with a supporting electrolyte (e.g. tetra-n-butylammonium perchlorate, TBAP). Acetonitrile, methylene chloride and nitrobenzene have been employed as solvents, but other favorites, such as benzene and cyclohexane, cannot be used. The relatively high dielectric constant of the suitable... 

Bruce and Harlow have presented additional evidence for this type of behavior. They did titrations in benzene, toluene, and gasoline. Figure 6 shows conductometric titrations in a solvent of very low dielectric constant. One of these phenols gives a conductometric curve with a very sharp peak at the point where half an equivalent of base has been added. The reason for the enhanced conductivity is that in solvents of low dielectric constant, these association complexes between the two molecules are greatly protonated. In the case ofthe other phenol, which is substituted in the 2,6- positions, this sort of association is sterically hindered. 

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