Abstract: A novel isopolyanion salt [(CH₃Py)₂H]₂W₆O₁₉ was synthesized by the reaction of a white powdery tungstic acid (WPTA) with p-methylpyridine, and characterized by elemental analyses, infrared spectrometry and X-ray diffraction methods. In the crystal structure of the title compound there are a hexatungstate anion and two unique [(CH₃Py)₂H]⁺ dimeric cations, and the most specific aspect of its structure is the first reported hydrogen bond existing between two of the p-methylpyridine molecules with a N_N distance of 0.267 3 nm. This hydrogen bond is analogous to that between the water molecules in H₅O₂⁺, but is rather weaker.

Key words: Di-p-methylpyridinium-p-methylpyridine hexatungstate, Hydrogen bond, Crystal structure