Date Published: August 01, 2009
Publisher: International Union of Crystallography
Author(s): Hoong-Kun Fun, Kasthuri Balasubramani, Chin Sing Yeap.
In the title salt, 2C5H8N3+·C4H4O42−·3H2O, the asymmetric unit contains a protonated 2,3-diaminopyridinium cation, half of a succinate dianion (disposed about a centre of inversion), and one and a half water molecules. One of the water molecules is disordered over two sites with occupancies of 0.670 (17) and 0.330 (17). The other water molecule has an occupancy of 0.5 (from refinement). The pyridine N atom of the 2,3-diaminopyridine molecule is protonated. The protonated N atom and one of the 2-amino H atoms are hydrogen bonded to the succinate anion through a pair of N—H⋯O hydrogen bonds, forming an R22(8) ring motif. In the crystal, molecules are consolidated into a three-dimensional network by N—H⋯O and O—H⋯O interactions.
For substituted pyridines, see: Pozharski et al. (1997 ▶); Katritzky et al. (1996 ▶); Jeffrey & Saenger (1991 ▶); Jeffrey (1997 ▶); Scheiner (1997 ▶). For related structures, see: De Cires-Mejias et al. (2004 ▶); Fun & Balasubramani (2009 ▶); Balasubramani & Fun (2009a ▶,b ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).