Phenols o-chlorophenol

Fig. 8-6 Log /f - ApiC plot for ideal case, imidazole (pX = 6.95, donors glucose, phenol, HP207, p-nitrophenol, acetic acid) and acetylacetonate (pX = 9.5, donors H2O, glycerine, mannose, glucose, trimethylphenol, phenol, o-chlorophenol, w-nitrophenol, p-nitrophenol, dimedone, acetic acid, benzoic acid, chloraoetic acid, (Data from Eigen and Kruse [12],...

A phenol/o-chlorophenol (mole ratio 10/1) solution buffered at pH = 10.5 with NaOH was electrolyzed at Fe anodes by various potential differences applied during different times the resulting polyoxyphenylene coatings at the best were below 0.05 mg/cm. Conversely when to the same solution 1% ethylenediamine was added, under the same conditions of electrolysis homogeneous, good coatings reaching... 

The reaction products are chlorophenols and no effect of these species is observed in the kinetic data, the rates falling in the order phenol >w-chloro-phenol > o-chlorophenol > p-chlorophenol> 2,4-dichlorophenol. 

Dichlorophenols. Among all the dichlorophenols, C H Cl O, it is 2,4-dichlorophenol that is produced in greatest quantity. 2,4-Dichlorophenol is used in manufacturing 2,4-dichlorophenoxyacetic acid [94-75-7] (2,4-D) and 2-(2,4-dichlorophenoxy)propionic acid [720-36-5] (2,4-DP). Industrially, 2,4-dichlorophenol can be obtained by chlorinating phenol, -chlorophenol, o-chlorophenol, or a mixture of these compounds in cast-iron reactors. The chlorinating agent may be chlorine or sulfuryl chloride in combination with a Lewis acid. For example ... 

Poly(alkylene terephthalate)s are soluble only in solvents such as 1,1,2,2-tetrachloroethane-phenol or o-cresol-CHCl3 mixtures, o-chlorophenol,... 

Problem 19,14 Assign numbers from 1 for least to 4 for most to indicate the relative acid strengths in the following groups (a) phenol, m-chlorophenol, m-nitrophenol, m-cresol (b) phenol, benzoic acid, p-nitro-phenol, carbonic acid (c) phenol, p-chlorophenol, p-nitrophenol, p-cresol (d) phenol, o-nitrophenol, m-nitrophenol, p-nitrophenol (e) phenol, p-chlorophenol, 2,4,6-trichlorophenol, 2,4-dichlorophenol (/) phenol, benzyl alcohol, benzenesulfonic acid, benzoic acid. ... 

Fig.4.71. Separation of some chlorophenols by cerium(IV) oxidation and fluorimetric detection. Column Corasil-C, 0.61 m X 4.83 mm I.D. Gradient elution from water to 36% acetonitrile-64% water. Peaks 1 = phenol (18.4 ppb) 2 = o-chlorophenol (22.S ppb) 3 = p-chlorophenol (20.2 ppb) 4 2,4-dichlorophenol (52.2 ppb) 5 = 2,4,6-trichlorophenol (42.6 ppb) S = solvent.

At neutral pH values, a high variation of reactivity of o-chlorophenol with ozone is observed with small changes in pH. These /cD values were found after gas-liquid kinetic model application to experimental data. Thus, the ozonation of o-chlorophenol was found to be a pseudo first-order fast gas liquid reaction as found by Hoigne and Bader [46] in homogeneous ozonation experiments. Trends of /cD with pH for other ozone-phenol reactions are similar to that depicted in Fig. 9. 

Remarks. The action of free chlorine on phenol is so vigorous that trichloro-phenol is formed at once. Monochlorophenol can ako be prepared by adding the calculated quantity of sodium hypochlorite solution to a cold solution of phenol in sodium hyproduct obtained by this method, however, is chieffy o-chlorophenol. 

Figure 13. Plot of (VssIl/2)" (corrected for T- changes due to viscosity) against [SH]- for naphthaquinone reduced by isopropanol (O) alone, and in the presence of phenol (O) or penta-chlorophenol (A) at 0°C.

The hydroxylation of phenol to catechol and hydroquinone with H2O2, introduced in the 1970s, represented a major advance over earlier methods of production, which utilized the alkaline fusion of o-chlorophenol (catechol) and the stoichiometric oxidation of aniline with manganese dioxide (hydroquinone). The inorganic and organic wastes in both processes were of the order of several kg per kg of product. However, the hydroxylation of phenol too is not free of drawbacks one is the co-production of two chemicals, destined for two... 

Phenol-methyl acetate Phenol-ethyl acetate Phenol-methylchloro acetate p-Chlorophenol-methyl acetate m-Chlorophenol-methyl acetate o-Chlorophenol-methyl acetate a-Naphthol-methyl acetate... 

Chem. 60, 1311-14 (1956). NMR effect of concentration, phenol, o-, m-,/>-chlorophenol, acetic acid in CCI4. 

Mostafa et al. [416] noted that the uptake of substituted phenols did not follow Traube s rule but instead did decrease in the order of their increasing pK values o-chlorophenol > hydroquinone > resorcinol > phenol > catechol > pyrogallol. Even though the experiments were performed at (unspecified) pH where the adsorbates were predominantly in an undissociated form, the authors noted that the acidity of the adsorbate is an important factor in determining its adsorption capacity this was not surprising to them because, presumably, the ability [of steam-activated and thus alkaline carbons] to remove phenols is expected to... 

In search of less expensive, less toxic, and lower viscosity eluants, a few authors have proposed diluting the active ingredient with a common SEC eluant such as toluene, dichloromethane, or chloroform. To lower the operating temperature and minimize polymer degradation, mixtures of m-cresol with chlorobenzene (50 50, v/v, 43°C), dichloromethane (50 50, room temperature), and chloroform have been used, with 0.25 wt% benzoic acid added to prevent adsorption. In the same vein, o-chlorophenol has been diluted with chloroform (25 75) and used at 20°C. The main disadvantage in this latter solvent was a small dnidc for the polymer, which rendered refractive index measurements difficult. In addition, careful purification of the phenol is required to obtain a detection signal. Dichloroacetic acid diluted to 20 vol% with dichloromethane has been proposed as the mobile phase. However, even at this concentration, PA tends to degrade at room temperature. 

As expected, substituents at the o-position will affect the bond angles. Therefore, a2 in both o-chlorophenols and o-bromophenols is larger than in the p-substituted phenols. The other bond angles are adjusted accordingly. 

Figure 18.12 Systematic optimization of the separation often phenols (reproduced by permission of Du Pont). Peaks 1 = phenol 2 = p-nitrophenol 3 = 2,4-dinitrophenol 4— o-chlorophenol 5— o-nitrophenol 6 = 2,4-dimethylphenol 7 = 4,6-dinitro-o-cresol S p-chloro-m-cresol 9 = 2,4-dichlorophenol 10 = 2,4, 6-trichlorophenol.

Hamdaoui, O. and Naffrehoux. E.. Modeling of adsorption isotherms of phenol and chlorophenols onto granulai- activated carbon. Part I. Two-parameter models and equations allowing determination of thermodynamic parameters, J. Hazardous Mater., 147, 381, 2007. 

Phenol is chlorinated to a mixture of p- and o-chlorophenol, with the para isomer definitely preferred (6 1 to 10 I). 

Polychloro dihydroxybiphenyls are mostly found with phenol and o -chlorophenol (eqns. 30, 31). 

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