Ionization constants of the six dichloroanilines and the six dichlorophenols in aqueous solution at 25 °C

Abstract

The thermodynamic ionization constants of the six dichloroanilines and the six dichlorophenols in aqueous solution at 25 ?C have been determined by the spectrophotometric method. The pK values found are recorded in table 3. An approximately linear relation is found to exist between the pKA value of a dichloroaniline and the pKp value of the corresponding dichlorophenol. The relation is [equation not included]. This equation yields pKA values which differ from the observed by not more than 0.06 pK unit and, on the average, by 0.03 pK unit; it applies even when both substituents are in the ortho position.