Yıldırım, Sema Öztürk; Akkurt, Mehmet; Pehlivanlar, Ezgi; Çetin, Gökalp; Şimşek, Rahime; Butcher, Ray J.; Bhattarai, Ajaya

The crystal structures and Hirshfeld surface analyses of three similar compounds are reported. Methyl 4-[4-(difluoromethoxy)phenyl]-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate, (C21H23F2NO4), (I), crystallizes in the monoclinic space group C2/c with Z = 8, while isopropyl 4-[4-(difluoro-methoxy)phenyl]-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate, (C23H27F2NO4), (II) and tert-butyl 4-[4-(difluoromethoxy)phenyl]-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate, (C24H29F2NO4), (III) crystallize in the orthorhombic space group Pbca with Z = 8. In the crystal structure of (I), molecules are linked by N—H. . .O and C—H. . .O interactions, forming a tri-periodic network, while molecules of (II) and (III) are linked by N—H. . .O, C—H. . .F and C—H. . .π interactions, forming layers parallel to (002). The cohesion of the molecular packing is ensured by van der Waals forces between these layers. In (I), the atoms of the 4-difluoromethoxyphenyl group are disordered over two sets of sites in a 0.647 (3): 0.353 (3) ratio. In (III), the atoms of the dimethyl group attached to the cyclohexane ring, and the two carbon atoms of the cyclohexane ring are disordered over two sets of sites in a 0.646 (3):0.354 (3) ratio.

Yıldırım, Sema Öztürk; Akkurt, Mehmet; Çetin, Gökalp; Şimşek, Rahime; Butcher, Ray J.; Bhattarai, Ajaya

In the title compound, C23H25F4NO3, the 1,4-dihydropyridine ring adopts a distorted boat conformation, while the cyclohexene ring is almost showing a half-chair conformation. In the crystal, intermolecular N—H· · ·O hydrogen bonds connect the molecules into chains with graph-set motif C(6) parallel to the a-axis. These chains are linked together by C—H· · ·O and C—H· · ·F interactions, forming a three-dimensional network. In addition, C—H· · ·π interactions link the molecules into layers parallel to the (100) plane. A Hirshfeld surface analysis was performed to further investigate the intermolecular interactions.

Yıldırım, Sema Öztürk; Akkurt, Mehmet; Çetin, Gökalp; Şimşek, Rahime; Butcher, Ray J.; Bhattarai, Ajaya

In the title compound, C24H29F2NO4, which crystallizes in the orthorhombic Pca21 space group with Z = 4, the 1,4-dihydropyridine ring adopts a distorted boat conformation, while the cyclohexene ring is in a distorted half-chair conformation. In the crystal, the molecules are linked by N—H· · ·O and C—H· · ·O interactions, forming supramolecular chains parallel to the a axis. These chains pack with C—H· · ·π interactions between them, forming layers parallel to the (010) plane. The cohesion of the crystal structure is ensured by van der Waals interactions between these layers. Hirshfeld surface analysis shows the major contributions to the crystal packing are from H· · ·H (56.9%), F· · ·H/H· · ·F (15.7%), O· · ·H/H· · ·O (13.7%) and C· · ·H/H· · ·C (9.5%) contacts.

Yildirim, Sema Öztürk; Akkurt, Mehmet; Çetin, Gökalp; Şimşek, Rahime; Butcher, Ray J.; Bhattarai, Ajaya

The title compound, C29H33NO3, crystallizes with three molecules (A, B and C) in the asymmetric unit. They differ in the twist of the phenyl and benzene rings of the 1,1′-biphenyl ring with respect to the plane of the 1,4-dihydropyridine ring. In all three molecules, the 1,4-dihydropyridine ring adopts a distorted boat conformation. The cyclohexene ring has an envelope conformation in molecules A and B, while it exhibits a distorted half-chair conformation for both the major and minor components in the disordered molecule C. In the crystal, molecules are linked by C-H⋯O and N-H⋯O hydrogen bonds, forming layers parallel to (100) defining R 1 4(6) and C(7) graph-set motifs. Additional C-H⋯π interactions consolidate the layered structure. Between the layers, van der Waals interactions stabilize the packing, as revealed by Hirshfeld surface analysis. The greatest contributions to the crystal packing are from H⋯H (69.6% in A, 69.9% in B, 70.1% in C), C⋯H/H⋯C (20.3% in A, 20.6% in B, 20.3% in C) and O⋯H/H⋯O (8.6% in A, 8.6% in B, 8.4% in C) interactions.

Çelik, Ísmail; Atioǧlu, Zeliha; Aksit, Huseyin; Demirtas, Ibrahim; Erenler, Ramazan; Akkurt, Mehmet

The title compound, C20 H32 O2 (systematic name: 3-ethenyl-3,4a,7,7,10a-pentamethyldodecahydro-9H-benzo[f]chromen-9-one), was isolated from Sideritis perfoliata. In the crystal, molecules pack in helical supramolecular chains along the 2 1 screw axis running parallel to the a axis, bound by C - H...O hydrogen bonds. These chains are efficiently interlocked in the other two unit-cell directions via van der Waals interactions. Hirshfeld surface analysis shows that van der Waals interactions constitute the major contribution to the intermolecular interactions, with H...H contacts accounting for 86.0% of the surface.