Crystal structure and Hirshfeld surface analysis of 1,6-di-amino-2-oxo-4-(thio-phen-2-yl)-1,2-di-hydro-pyridine-3,5-dicarbo-nitrile.

The asymmetric unit of the title compound, C 11 H 7 N 5 OS, contains two independent mol-ecules (1 and 2). The thio-phene ring in mol-ecule 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 thio-phene ring in mol-ecule 2 are not equivalent. In the crystal, mol-ecules are linked by inter-molecular 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 inter-actions and between the (022) planes by N-H⋯O hydrogen bonds. In mol-ecule 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%) inter-actions, while in mol-ecule 2, H⋯H (25.4%) inter-actions are the most significant contributors to the crystal packing.