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 degrees (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 center dot center dot center dot Oand N-H center dot center dot center dot 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 center dot center dot center dot O hydrogen bonds. In molecule 1, Hirshfeld surface analysis showed that the most important contributions to the crystal packing are from N center dot center dot center dot H/H center dot center dot center dot N (27.1%), H center dot center dot center dot H (17.6%), C center dot center dot center dot H/H center dot center dot center dot C (13.6%) and O center dot center dot center dot H/H center dot center dot center dot O (9.3%) interactions, while in molecule 2, H center dot center dot center dot H (25.4%) interactions are the most significant contributors to the crystal packing.

Automated summary

The title compound contains two independent molecules in its asymmetric unit. One of the molecules exhibits rotational disorder in the thiophene ring, with two orientations that are not equivalent. In the crystal, the molecules are connected by intermolecular hydrogen bonds and van der Waals interactions to form ribbons along the a-axis.