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

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...Oand 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. [ABSTRACT FROM AUTHOR]