Synthesis and crystalline structure of the cocrystal (2-O--PyH+)2·(2,6-pydcH2)

The interaction of 2-hydroxypyridine (2-OH-Py) with 2,6-pyridinedicarbonyl dichloride using acetonitrile as solvent led to the formation of a new cocrystal compound with the formula (2-O--PyH+)2·(2,6 pydcH2), where 2-O--PyH+ = pyridin-1-ium-2-olate and 2,6-pydcH2 = 2,6-pyridinedicarboxylic acid. The X ray study, which was used to determine the crystal structure of this compound, showed that in this compound both components are neutral, but 2-hydroxypyridine is stabilized as a zwitterion. In the crystal, 2-O--PyH+ associates in dimers via two N–H···O hydrogen bonds, as a result, the synthons R22(8) can be highlighted. In supramolecular chains these synhtons join together through O–H···O hydrogen bonds, involving the carboxyl groups as proton donors and the oxygen atoms in the dimers as acceptors.