Chlorobenzene, electrostatic

Chlorobenzene, electrostatic potential map of, 565 13C NMR absorptions of, 536 phenol from, 575 p-Chlorobenzoic acid, pKa of, 760... 

The reactions of chlorobenzene and benzaldehyde with ammonia over metal Y zeolites have been studied by a pulse technique. For aniline formation from the reaction of chlorobenzene and ammonia, the transition metal forms of Y zeolites show good activity, but alkali and alkaline earth metal forms do not. For CuY, the main products are aniline and benzene. The order of catalytic activity of the metal ions isCu> Ni > Zn> Cr> Co > Cd > Mn > Mg, Ca, Na 0. This order has no relation to the order of electrostatic potential or ionic radius, but is closely related to the order of electronegativity or ammine complex formation constant of metal cations. For benzonitrile formation from benzaldehyde and ammonia, every cation form of Y zeolite shows high activity. 

The simplest explanation of film rupture involves reaching a thermodynamically unstable state [20]. A typical example of thermodynamically unstable systems are foam films in which the disjoining pressure obeys Hamaker s relation. Such are films from some aqueous surfactant solutions containing sufficient amount of an electrolyte to suppress the electrostatic component of disjoining pressure as well as films from non-aqueous solutions (aniline, chlorobenzene) [e.g. 80],... 

Thus in the case of strong electrolytes the deviations are important even in very dilute solutions, and this is evidently related to the long range of action of electrostatic forces. On the other hand in some solutions, such as chlorobenzene + bromobenzene, where the two molecules are of closely similar chemical structure, the solutions deviate very little from ideality over the whole concentration range. Solutions which remain ideal at all concentrations are called perfect solutions. We shall return in the next paragraph to a consideration of the conditions which must be satisfied for a solution to be perfect. 

According to Pavlova (36) gaseous chlorobenzene, adsorbed on a silica gel plate, exhibits, in comparison with adsorbed benzene, a markedly smaller shift (40-90 cm i), which is an additional indication of the absence of an electrostatic interaction with the surface. The shift is somewhat different for the consecutive bands of the same progression. 

SULFURE de METHYLE (French) (75-18-3) Forms explosive mixture with air (flash point -36°F/-38°C). Reacts with water, steam, acids, acid fumes, producing hydrogen sulfide fumes, which can explode in air. Reacts violently with strong oxidizers, chlorobenzene-diazonium salts, mercurous chloride. Incompatible with zinc acetate. Flow or agitation of substance may generate electrostatic charges due to low conductivity. 

Compare the electrostatic potential maps of benzaldehyde (deactivated), chlorobenzene (weakly deactivated), and phenol (activated) with that of benzene. The ring is more positive (yellow) when an electron-withdrawing group such as -CHO or -Cl is present and more negative (red) when an electron-donating group such as -OH is present. 

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