Crystal structure and Hirshfeld surface analysis of 1,6-diamino-2-oxo-4-(thiophen-2-yl)-1,2-dihydropyridine-3,5-dicarbonitrile

Abstract

The asymmetric unit of the title compound, C11H7N5OS, contains two independent molecules (1 and 2). The thiophene ring in molecule 2 is rotationally disordered (flip disorder) by ca 180° (around the single C—C bond, to which it is attached) over two sites with the site-occupation factors of 0.9 and 0.1. These two orientations of the thiophene ring in molecule 2 are not equivalent. In the crystal, molecules are linked by intermolecular N—H...O and N—H...N hydrogen bonds into ribbons parallel to (022) along the a axis. Within the (022) planes, these ribbons are connected by van der Waals interactions and between the (022) planes by N—H...O hydrogen bonds. In molecule 1, Hirshfeld surface analysis showed that the most important contributions to the crystal packing are from N...H/H...N (27.1%), H...H (17.6%), C...H/H...C (13.6%) and O...H/H...O (9.3%) interactions, while in molecule 2, H...H (25.4%) interactions are the most significant contributors to the crystal packing.

Keywords

• crystal structure
• 1,2-dihydropyridine
• hydrogen bond
• disorder
• hirshfeld surface analysis