AbstractA correlation ofparasubstituted13C chemical shifts in aromatic compounds with substituent polar (inductive) and resonance constants σ* and σrof aliphatic compounds has been studied. It has been shown that the precision of the correlations obtained corresponds to that of the Swain‐Lupton and Taft two‐parameter equations, but the correlation equation used in this work seems to permit a more exact separation of the substituent effects of aromatic compounds into inductive and resonance contributions. Thus, σ* and σrsubstituent constants are universal parameters which can be used in a correlation analysis of the properties of both aliphatic and aromatic co