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 7.91 7 , 7.692, 8.284, 7.68o, and 5.27 8. 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 4.82o, respectively.