A 2,2-dimethylbutynoic acid with 7 pyridone terminus (1) acts as its self-complement in molecular recognition to form nn intermolecularly hydrogen-banded dimer with hydrogen bonding between the amide and carboxylic acid group. The dimer is found in crystals of 1 by X-ray diffraction, chloroform solution by H-1-NMR experiments and Vapor pressure osmometry, and in the gas phase by FAB-MS.