Linear Korrelation der 13C‐Kernresonanzfrequenzen mit den LCAO‐MO‐π‐Elektronendichten in substituierten Benzonitrilen

The 13C NMR. spectra of seventeen m‐ and p‐ subsituted benzonitriles were examined and partially anlayzed. The C‐1 carbon shieldings can be expressed in terms of a linear correlation with the LCAO‐MO‐π‐electron density at C‐1. No such correlation was found for the cyanocarbon, whose electron density shows only slight varriations for the different substitutents. This fact is consistent with the relatively small range of the chemical shifts at this center.