Noncovalent interactions between classical supramolecular synthons in solution: Hydrogen bonding in hindered 2-acylaminopyridine/2-pyridone associates

Two classical supramolecular synthons were studied in the light of heterocomplexation. The (6-methyl)-2-pyridones were associated with 2-acylaminopyridines and 6-methyl-2-acetylaminopyridine. Titrations monitored with 1H NMR showed that heterocomplexes were readily formed. The calculations at DFT level and the use of QTAIM methodology support experimental findings. The hydrogen bond length and the energy of association were correlated to Taft’s constants.