Some Critical Remarks Concerning the Inductive Parameter σI Part III: Parametrization of the Ortho Effect in Benzoic Acids and Phenols

Abstract
Correlation analysis was applied to pKa values of a series of 63 benzoic acids and a series of 64 phenols in order to obtain more evidence for the correct rules of parametrization of orthosubstituents as suggested by Fujita and Nishioka in 1976.For the inductive effect parameter σI‐used in this type of equations ‐ again a σI = 0.00 parametrization for alkyl groups is applied. The results are in agreement with the findings for aliphatic amines and aliphatic carboxylic acids as discussed in previous papers in this series.Good correlation with r = 0.9982 for benzoic acids and r = 0.9987 for phenols could be made.