Hammett correlations between 13C-NMR chemicalshifts of the azomethine carbon atom and the corresponding substituent constants for thirtheen Schiff bases were established. Successful correlation of the chemicalshifts with electrophilic substituent constants o+ indicate significant resonance interaction of the substituents on the aniline ring with the azomethine carbon atom in the examined series of imines
pentafluorophenyl salicylamine (1a) as a π-acceptor for anion–πinteractions. Crystals of 1a·HCl show that the OH-group fixes the anion in a η2-type binding motif above the electron-deficient arene. Attempts to find some relevance for this weakintermolecular force in solution failed. Stronger CH–, NH– and OH–anion interactions are dominant over the weakanion–πinteractions. Due to the hydrogen bonding, the non-fluorinated