2-Pyridone–tartronic acid (1/1), 3-hydroxypyridinium hydrogen tartronate and 4-hydroxypyridinium hydrogen tartronate
Abstract:Tartronic acid forms a hydrogen-bonded complex, C5H5NO·C3H4O5, (I), with 2-pyridone, while it forms acid salts, namely 3-hydroxypyridinium hydrogen tartronate, (II), and 4-hydroxypyridinium hydrogen tartronate, (III), both C5H6NO+·C3H3O5−, with 3-hydroxypyridine and 4-hydroxypyridine, respectively. In (I), the pyridone molecules and the acid molecules form R (8) and R (10) hydrogen-bonded rings, respectively, around the inversion centres. In (II) and (III), the cations and anions are linked by N—H…O and O—H…O hydrogen bonds to form a hydrogen-bonded chain. In each of (I), (II) and (III), an intermolecular hydrogen bond is formed between a carboxyl group and the hydroxyl group attached to the central C atom, and in (I), the hydroxyl group participates in an intramolecular hydrogen bond with a carbonyl group. No intermolecular hydrogen bond is formed between the carboxyl groups in (I), or between the carboxyl and carboxylate groups in (II) and (III).
Document Type: Research Article
Publication date: 2004-10-01