2-Pyridone: monoclinic polymorph

Abstract

The asymmetric unit in the title compound, C5H5NO, comprises two independent but virtually identical molecules of 2-pyridone, and represents a monoclinic polymorph of the previously reported orthorhombic (P212121) form [Penfold (1953). Acta Cryst. 6, 591–600; Ohms et al. (1984). Z. Kristallogr. 169, 185–200; Yang & Craven (1998). Acta Cryst. B54, 912–920]. The independent molecules are linked into supramolecular dimers via eight-membered {...HNC(O)}2 amide synthons in contrast to the helical supramolecular chains, mediated by {...HNC(O)} links, found in the orthorhombic form.