Crystal structures and Hirshfeld surface analyses of 2-amino-4-(4-bromo-phen-yl)-6-oxo-1-phenyl-1,4,5,6-tetra-hydro-pyridine-3-carbo-nitrile hemi-hydrate and 1,6-di-amino-2-oxo-4-phenyl-1,2-di-hydro-pyridine-3,5-dicarbo-nitrile.

In 2-amino-4-(4-bromo-phen-yl)-6-oxo-1-phenyl-1,4,5,6-tetra-hydro-pyridine-3-carbo-nitrile hemihydrate, C(18)H(14)BrN(3)O·0.5H(2)O, (I), pairs of mol-ecules are linked by pairs of N-H⋯N hydrogen bonds, forming dimers with an R (2) (2)(12) ring motif. The dimers are connected by N-H⋯Br and O-H⋯O hydrogen bonds, and C-Br⋯π inter-actions, forming layers parallel to the (010) plane. 1,6-Di-amino-2-oxo-4-phenyl-1,2-di-hydro-pyridine-3,5-dicarbo-nitrile, C(13)H(9)N(5)O, (II), crystallizes in the triclinic space group P with two independent mol-ecules (IIA and IIB) in the asymmetric unit. In the crystal of (II), mol-ecules IIA and IIB are linked by inter-molecular N-H⋯N and N-H⋯O hydrogen bonds into layers parallel to (001). These layers are connected along the c-axis direction by weak C-H⋯N contacts. C-H⋯π and C-N⋯π inter-actions connect adjacent mol-ecules, forming chains along the a-axis direction. In (I) and (II), the stability of the packing is ensured by van der Waals inter-actions between the layers. In (I), Hirshfeld surface analysis showed that the most important contributions to the crystal packing are from H⋯H (37.9%), C⋯H/H⋯C (18.4%), Br⋯H/H⋯Br (13.3%), N⋯H/H⋯N (11.5%) and O⋯H/H⋯O (10.0%) inter-actions, while in (II), H⋯H inter-actions are the most significant contributors to the crystal packing (27.6% for mol-ecule IIA and 23.1% for mol-ecule IIB).