Dissociation of Some Substituted Phenols in 50-Percent Aqueous Methanol as Solvent.

Abstract

The dissociation constants of the following substituted phenols in 50 wt percent methanol have been measured at 25 °C: o-nitrophenol, p-nitrophenol, 4-methyl-2-nitrophenol, 2,6-dichlorophenol, pentachlorophenol. The respective values found, expressed as pK values, are 7.917, 7.692, 8.284, 7.680, and 5.278. The dissociation constants of 4-methyl-2-nitrophenol and pentachlorophenol, again expressed as pK values, have been measured in water as solvent at 25 °C and found to be 7.597 and 4.820, respectively.