Crystal structure and Hirshfeld surface analysis of dimethyl 4'-bromo-3-oxo-5-(thio-phen-2-yl)-3,4,5,6-tetra-hydro-[1,1'-biphen-yl]-2,4-di-carboxyl-ate.

In the title compound, C20H17BrO5S, mol-ecules are connected by inter-molecular C-H⋯S hydrogen bonds with R 2 2(10) ring motifs, forming ribbons along the b-axis direction. C-H⋯π inter-actions consolidate the ribbon structure while van der Waals forces between the ribbons ensure the cohesion of the crystal structure. According to a Hirshfeld surface analysis, H⋯H (40.5%), O⋯H/H⋯O (27.0%), C⋯H/H⋯C (13.9%) and Br⋯H/H⋯Br (11.7%) inter-actions are the most significant contributors to the crystal packing. The thio-phene ring and its adjacent di-carboxyl-ate group and the three adjacent carbon atoms of the central hexene ring to which they are attached were refined as disordered over two sets of sites having occupancies of 0.8378 (15) and 0.1622 (15). The thio-phene group is disordered by a rotation of 180° around one bond.

Crystal structure and Hirshfeld surface analysis of 1-(2-amino-4-methyl-1,3-thia-zol-5-yl)ethan-1-one.

In the title compound, C6H8N2OS, all atoms except for the methyl H atoms are coplanar, with a maximum deviation of 0.026 (4) Å. In the crystal, pairs of mol-ecules are linked by N-H⋯N hydrogen bonds, forming R 2 2(8) ring motifs. Dimers are connected by N-H⋯O hydrogen bonds, forming layers parallel to the (102) plane. Consolidating the mol-ecular packing, these layers are connected by C-H⋯π inter-actions between the center of the 1,3-thia-zole ring and the H atom of the methyl group attached to it, as well as C=O⋯π inter-actions between the center of the 1,3-thia-zole ring and the O atom of the carboxyl group. According to a Hirshfeld surface study, H⋯H (37.6%), O⋯H/H⋯O (16.8%), S⋯H/H⋯S (15.4%), N⋯H/H⋯N (13.0%) and C⋯H/H⋯C (7.6%) inter-actions are the most significant contributors to the crystal packing.

Crystal structure and Hirshfeld surface analysis of (2E)-1-(4-bromo-phen-yl)-3-(2-methyl-phen-yl)prop-2-en-1-one.

In the title com-pound, C16H13BrO, the planes of the aromatic rings are inclined at an angle of 23.49 (15)°, and the configuration about the C=C bond is E. In the crystal, the mol-ecules are linked into chains by weak C-H⋯O inter-actions along the b axis. Successive chains form a zigzag structure along the c axis, and these chains are connected to each other by face-to-face π-π stacking inter-actions along the a axis. These layers, parallel to the (001) plane, are linked by van der Waals inter-actions, thus consolidating the crystal structure. Hirshfeld surface analysis showed that the most significant contacts in the structure are H⋯H (43.1%), C⋯H/H⋯C (17.4%), Br⋯H/H⋯Br (14.9%), C⋯C (11.9%) and O⋯H/H⋯O (9.8%).

Crystal structure and Hirshfeld surface analysis of 2-amino-5-{(1E)-1-[(carbamo-thioyl-amino)-imino]eth-yl}-4-methyl-1,3-thia-zol-3-ium chloride monohydrate.

In the hydrated title salt, C7H12N5S2 +·Cl-·H2O, the asymmetric unit comprises one 2-amino-5-{(1E)-1-[(carbamo-thioyl-amino)-imino]-eth-yl}-4-methyl-1,3-thia-zol-3-ium cation, one chloride anion and one water mol-ecule of crystallization. The cation is nearly flat (r.m.s. deviation of non-H atoms is 0.0814 Å), with the largest deviation of 0.1484 (14) Šobserved for one of the methyl C atoms. In the crystal, the cations are linked by O-H⋯Cl, N-H⋯Cl, N-H⋯O, N-H⋯S and C-H⋯S hydrogen bonds, forming a tri-periodic network. The most important contributions to the crystal packing are from H⋯H (35.4%), S⋯H/H⋯S (24.4%), N⋯H/H⋯N (8.7%), Cl⋯H/H⋯Cl (8.2%) and C⋯H/H⋯C (7.7%) inter-actions.

Crystal structure and Hirshfeld surface analysis of 2-amino-6-[(1-phenyl-eth-yl)amino]-4-(thio-phen-2-yl)pyridine-3,5-dicarbo-nitrile.

In the title compound, C19H15N5S, the thio-phene ring is disordered in a 0.6:0.4 ratio by an approximate 180° rotation of the ring around the C-C bond linking it to the pyridine ring. In the crystal, the mol-ecules are linked by N-H⋯N hydrogen bonds into dimers with an R 2 2(12) motif, forming chains along the b-axis direction. These chains are connected to each other by further N-H⋯N hydrogen bonds, forming a three-dimensional network. Furthermore, N-H⋯π and π-π [centroid-centroid separations = 3.899 (8) and 3.7938 (12) Å] inter-actions also contribute to the crystal cohesion. A Hirshfeld surface analysis indicated that the most important contributions to the surface contacts are from H⋯H (46.1%), N⋯H/H⋯N (20.4%) and C⋯H/H⋯C (17.4%) inter-actions.

Crystal structure and Hirshfeld surface analysis of 2-amino-4-(4-meth-oxy-phen-yl)-6-oxo-1-phenyl-1,4,5,6-tetra-hydro-pyridine-3-carbo-nitrile.

The central tetra-hydro-pyridine ring of the title compound, C19H17N3O2, adopts a screw-boat conformation. In the crystal, strong C-H⋯O and N-H⋯N hydrogen bonds form dimers with R 2 2(14) and R 2 2(12) ring motifs, respectively, between consecutive mol-ecules along the c-axis direction. Inter-molecular N-H⋯O and C-H⋯O hydrogen bonds connect these dimers, forming a three-dimensional network. C-H⋯π inter-actions and π-π stacking inter-actions contribute to the stabilization of the mol-ecular packing. A Hirshfeld surface analysis indicates that the contributions from the most prevalent inter-actions are H⋯H (47.1%), C⋯H/H⋯C (20.9%), O⋯H/H⋯O (15.3%) and N⋯H/H⋯N (11.4%).

Crystal Structure and Hirshfeld Surface Analysis of Acetoacetanilide Based Reaction Products.

We report an unprecedented multicomponent reaction of acetoacetanilide with malononitrile leading to a structurally novel bicyclic product (9) in a high yield. The structure has been confirmed by X-ray crystallography and comparative Hirshfeld surface analysis of 5-cyano-2-hydroxy-2-methyl-N-phenyl-4-(yridine-4-yl)-6-(thiophen-2-yl)-3,4-dihydro-2H-pyran-3-carboxamide 2, 5-cyano-2-hydroxy-2-methyl-6-oxo-N-phenyl-4-(thiophen-2-yl)piperidine-3-carboxamide 4 and 2-(8-amino-7,8a-dicyano-1-imino-4a-methyl-3-oxo-2-phenyl-1,3,4,4a,5,8a-hexahydroisoquinolin-6(2H)-ylidene)-N-phenylacetamide 9.