Phonon-Driven Proton Transfer in 3,5-Pyridine Dicarboxylic Acid Studied by 2H, 14N, and 17O Nuclear Quadrupole Resonance

Hydrogen bonding in crystalline 3,5-pyridine dicarboxylic acid has been studied by 2H, 14N, and 17O nuclear quadrupole resonance. The 2H and 17O data show the presence of two distinct hydrogen bonds, a “normal” O–H···O bond and a short, strong N···H···O bond, with significantly different NQR parameters. In the latter, the temperature variation of the 14N nuclear quadrupole resonance (NQR) parameters is related to the phonon-driven proton transfer in the N···H···O hydrogen bond. The temperature dependence of the N···H and H···O distances in the N···H···O hydrogen bond is extracted from the 14N NQR data.