Crystal structures of (12E)-12-(4-benzyl-idene)-7,7,16-trimethyl-3-(4-methyl-phen-yl)-1-oxa-16-aza-tetra-cyclo-[11.2.1.02,11.04,9]hexa-deca-2(11),4(9)-dien-5-one and (12E)-12-(4-bromo-benzyl-idene)-73-(4-bromo-phen-yl)-,7,16-trimethyl-10-oxa-16-aza-tetra-cyclo-[11.2.1.02,11.04,9]hexa-deca-2(11),4(9)-dien-5-one.

The title compounds, C32H35NO2, (I), and C30H29Br2NO2, (II), differ by the presence of a bromine atom instead of a methyl atom in the para position of two benzene rings of compound (II). The two compounds have a structural overlap r.m.s. deviation of 0.27 Å. The pyran and seven-membered cyclo-heptene rings in both structures adopt boat and boat-sofa conformations, respectively. Intra- and inter-molecular C-H⋯O hydrogen bonds are responsible for the consolidation of the crystal packing of both mol-ecules. In addition to this, weak C-H⋯π inter-actions are also observed. The inter-molecular inter-actions were qu-anti-fied and analysed using Hirshfeld surface analysis.

Crystal structure of 7'-(4-chloro-phen-yl)-2''-(4-meth-oxy-phen-yl)-7',7a',7'',8''-tetra-hydro-1'H,3'H,5''H-di-spiro-[indoline-3,5'-pyrrolo-[1,2-c]thia-zole-6',6''-quinoline]-2,5''-dione and an unknown solvent.

The asymmetric unit of the title compound, C34H28ClN3O3S, contains two independent mol-ecules (A and B). They differ essentially in the orientation of the 4-meth-oxy-phenyl ring with respect to the pyridine ring of the quinoline moiety; this dihedral angle is 37.01 (18)° in mol-ecule A but only 7.06 (17)° in mol-ecule B. In both mol-ecules, the cyclo-hexa-none ring of the iso-quinoline unit has a half-chair conformation. In the pyrrolo-thia-zole ring system, the pyrrolo ring in mol-ecule A has a twisted conformation on the N-C fused bond and an envelope conformation in mol-ecule B with the N atom as the flap. The thia-zole rings of both mol-ecules have twisted conformations on the N-C fused bond. In the crystal, the A mol-ecules are linked by pairs of N-H⋯O hydrogen bonds, forming inversion dimers with an R 2 2(8) ring motif. These dimers are linked to the B mol-ecules by an N-H⋯N hydrogen bond and a series of C-H⋯O hydrogen bonds, forming layers lying parallel to the (101) plane. The layers are linked by C-H⋯π inter-actions and offset π-π inter-actions [inter-centroid distance = 3.427 (1) Å], forming a supra-molecular framework. The contribution to the scattering from a region of highly disordered solvent mol-ecules was removed with the SQUEEZE routine in PLATON [Spek (2015 ▸). Acta Cryst. C71, 9-18]. The solvent formula mass and unit-cell characteristics were not taken into account during refinement.

Crystal structure and Hirshfeld surface analysis of 4'-(2-chloro-phen-yl)-1'-methyl-3''-phenyl-7'',8''-di-hydro-5''H-di-spiro-[indoline-3,2'-pyrrolidine-3',6''-iso-quinoline]-2,5''-dione.

In the title di-spiro compound, C32H26ClN3O2, the cyclo-hexa-none ring of the iso-quinoline unit has a distorted envelope conformation, with the methyl-ene C atom adjacent to the spiro C atom as the flap. The central 1-methyl-pyrrolidine ring has an envelope conformation with the N atom as the flap. The mean planes of the indolin-2-one ring system, the chloro-benzene ring and the iso-quinoline ring system are inclined to the mean plane of the central 1-methyl-pyrrolidine ring by 87.95 (11), 71.01 (12) and 88.81 (10)°, respectively. There are two short C-H⋯O intra-molecular contacts present. In the crystal, mol-ecules are linked via C-H⋯ O hydrogen bonds, forming chains along the a-axis direction. The NH H atom is involved in a weak N-H⋯O hydrogen bond with the same carbonyl O atom. There are no further significant inter-molecular contacts present. The largest contribution to the overall Hirshfeld surface of 52.3% is due to H-H contacts.

Crystal structure of 4-(1H-indol-3-yl)-2-(4-meth-oxy-phen-yl)-6-phenyl-pyridine-3-carbo-nitrile.

In the title compound, C27H19N3O, the dihedral angles between the plane of the pyridine ring and those of the indole (r.m.s. deviation = 0.018 Å), phenyl and meth-oxy-benzene substituents are 33.60 (6), 25.28 (7) and 49.31 (7)°, respectively. The N atom of the carbo-nitrile group is significantly displaced [0.288 (2) Å] from the plane of the pyridine ring, perhaps due to steric crowding. In the crystal, inversion dimers linked by pairs of N-H⋯Nn (n = nitrile) hydrogen bonds generate R 2 (2)(16) loops. Aromatic π-π stacking [centroid-centroid separation = 3.6906 (7) Å] and very weak C-H⋯π inter-actions are also observed".

Crystal structure of 2-(2-bromo-phen-yl)-4-(1H-indol-3-yl)-6-(thio-phen-2-yl)pyridine-3-carbo-nitrile.

In the title compound, C24H14BrN3S, the dihedral angles between the planes of the pyridine ring and the pendant thio-phene ring, the indole ring system (r.m.s. deviation = 0.022 Å) and the bromo-benzene ring are 9.37 (17), 21.90 (12) and 69.01 (15)°, respectively. The approximate coplanarity of the central ring and the indole ring system is supported by two intra-molecular C-H⋯N inter-actions. In the crystal, inversion dimers linked by pairs of N-H⋯N hydrogen bonds generate R 2 (2)(16) loops and the dimers are linked by C-H⋯π and aromatic π-π stacking [shortest centroid-centroid separation = 3.729 (3) Å] into a three-dimensional network.

Crystal structure of 2-(4-chloro-phen-yl)-4-(1H-indol-3-yl)-6-phenyl-pyridine-3-carbo-nitrile.

In the title compound, C26H16ClN3, the dihedral angles between the central pyridine ring and the pendant phenyl, chloro-benzene and indole rings are 18.52 (12), 48.97 (11) and 21.20 (10)°, respectively. An intra-molecular C-H⋯Nc (c = cyanide) hydrogen bond occurs. In the crystal, inversion dimers linked by pairs of N-H⋯Nc hydrogen bonds generate R 2 (2)(16) loops.

4-(2-Fluoro-phen-yl)-2-meth-oxy-5,6,7,8,9,10-hexa-hydro-cyclo-octa-[b]pyridine-3-carbo-nitrile.

In the title compound, C19H19FN2O, the cyclo-octene ring adopts a twisted boat-chair conformation. The dihedral angle between the plane of the fluorophenyl substituent and that of the pyridine ring is 76.39 (8)°. The F and ortho-H atoms of the fluoro-benzene ring are disordered, with occupancy factors of 0.226 (5) and 0.774 (5). In the crystal, no significant inter-actions are observed between the mol-ecules beyond van der Waals contacts.

2-Meth-oxy-4-(2-meth-oxy-phen-yl)-5,6,7,8,9,10-hexa-hydro-cyclo-octa-[b]pyridine-3-carbo-nitrile.

In the title compound, C20H22N2O2, the central pyridine ring forms a dihedral angle of 76.32 (8)° with the pseudo-axial benzene ring. The cyclo-octane ring adopts a twisted boat chair conformation. In the crystal, weak inter-molecular C-H⋯π inter-actions between inversion-related mol-ecules result in the formation of linear double chains along the b-axis direction.

C-H···O and C-H···N interactions in three hexahydrocycloocta[b]pyridine-3-carbonitriles.

The structures of three new pyridine derivatives, 2-methoxy-4-(4-methoxyphenyl)-5,6,7,8,9,10-hexahydrocycloocta[b]pyridine-3-carbonitrile, C20H22N2O2, (I), 2-ethoxy-4-(3-nitrophenyl)-5,6,7,8,9,10-hexahydrocycloocta[b]pyridine-3-carbonitrile, C20H21N3O3, (II), and 2-ethoxy-4-(4-methoxyphenyl)-5,6,7,8,9,10-hexahydrocycloocta[b]pyridine-3-carbonitrile, C21H24N2O2, (III), differ in the nature of the substituents either at the 2-position of the central pyridine ring or on the pendent aryl ring. This simple change in the structure substantially alters the intermolecular interaction patterns. The substituted phenyl group adopts a synclinal geometry with respect to the plane of the pyridine ring in all three compounds. In (I), a C-H···N interaction results in a one-dimensional chain parallel to the b axis. In (II), there are two C-H···N(nitrile) interactions from different symmetry-related molecules, resulting in a two-dimensional network parallel to the bc plane. There is also a weak C-H···O interaction from the ethoxy group to an adjacent nitro O atom. The present work is an example of how the simple replacement of a substituent in the main molecular scaffold may transform the structure type, paving the way for a variety of supramolecular motifs and consequently altering the complexity of the intermolecular interaction patterns.

5''-(4-Nitro-benzyl-idene)-7'-(4-nitro-phen-yl)-1''-methyl-1',3',5',6',7',7a'-hexa-hydro-dispiro-[ace-naphthyl-ene-1,5'-pyrrolo-[1,2-c][1,3]thia-zole-6',3''-piperidine]-2,4''(1H)-dione including an unknown solvate.

The title compound, C35H28N4O6S, crystallizes with two mol-ecules in the asymmetric unit. In both mol-ecules, the piperidine ring adopts a shallow-chair conformation, the thia-zole ring adopts a twisted conformation about the Cm-N bond (m = methine) and the pyrrole ring adopts an envelope conformation with the C atom shared with the thia-zole ring as the flap. In the crystal, inversion dimers linked by pairs of C-H⋯O inter-actions generate R 2 (2)(34) loops for one of the asymmetric mol-ecules. Further C-H⋯O links also involving the other mol-ecule lead to a three-dimesional network. The contribution of the highly disordered solvent to the scattering was removed with SQUEEZE option of PLATON [Spek (2009 ▶). Acta Cryst. D65, 148-155]. The solvent contribution is not included in the reported mol-ecular weight and density.

5''-(2-Fluoro-benzyl-idene)-1'-(2-fluoro-phen-yl)-1''-methyl-1',2',3',5',6',7',8',8a'-octa-hydro-dispiro-[ace-naphthyl-ene-1,3'-indolizine-2',3''-piperidine]-2,4''(1H)-dione.

In the title compound, C37H32F2N2O2, the central six-membered piperidine ring adopts a twisted half-chair conformation, with the N and methyl-ene C atoms deviating by -0.2875 (16) and 0.4965 (15) Å, respectively, from the mean plane defined by the other four atoms. The piperidine connected to the octa-hydro-indolizine ring is in a half-chair conformation. The five-membered pyrrole ring adopts a slightly twisted envelope conformation with the piperidine C atom as the flap atom. The F and H atoms of both fluoro-benzene rings are disordered, with occupancy factors of 0.941 (3):0.059 (3) and 0.863 (3):0.137 (3). The mol-ecular structure features some intra-molecular C-H⋯O inter-actions. In the crystal, a supra-molecular zigzag chain sustained by C-H⋯F inter-actions parallel to the c axis is formed, generating a C(12) graph-set motif.

(3E,5E)-1-Allyl-3,5-bis(4-meth-oxy-benzyl-idene)-piperidin-4-one.

The piperidine ring in the title compound, C24H25NO3, adopts an envelope conformation with the N atom being the flap atom, and each C=C double bond exhibits an E conformation. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules, forming supramolecular layers that stack along the a axis.

4-(4-Fluoro-phen-yl)-6-methyl-amino-5-nitro-2-phenyl-4H-pyran-3-carbo-nitrile.

In the title compound, C19H14FN3O3, the central pyran ring adopts a boat conformation with the O atom and the quaternary C atom diagonally opposite displaced by 0.068 (1) and 0.075 (1) Å, respectively, above the mean plane defined by the other four ring atoms. The co-planar atoms of the pyran ring and the fluoro-phenyl ring are nearly perpendicular, as evidenced by the dihedral angle of 87.11 (1)°. The amine group forms an intra-molecular N-H⋯O(nitro) hydrogen bond. In the crystal, mol-ecules are linked into parallel chains along [100] by weak N-H⋯N and C-H⋯N(nitro) hydrogen bonds, generating C(8) and C(9) graph-set motifs, respectively.

N-H···O and N-H···N interactions in three pyran derivatives.

The three pyran structures 6-methylamino-5-nitro-2,4-diphenyl-4H-pyran-3-carbonitrile, C19H15N3O3, (I), 4-(3-fluorophenyl)-6-methylamino-5-nitro-2-phenyl-4H-pyran-3-carbonitrile, C19H14FN3O3, (II), and 4-(4-chlorophenyl)-6-methylamino-5-nitro-2-phenyl-4H-pyran-3-carbonitrile, C19H14ClN3O3, (III), differ in the nature of the aryl group at the 4-position. The heterocyclic ring in all three structures adopts a flattened boat conformation. The dihedral angle between the pseudo-axial phenyl substituent and the flat part of the pyran ring is 89.97 (1)° in (I), 80.11 (1)° in (II) and 87.77 (1)° in (III). In all three crystal structures, a strong intramolecular N-H···O hydrogen bond links the flat conjugated H-N-C=C-N-O fragment into a six-membered ring. In (II), molecules are linked into dimeric aggregates by N-H··· O(nitro) hydrogen bonds, generating an R2(2)(12) graph-set motif. In (III), intermolecular N-H···N and C-H···N hydrogen bonds link the molecules into a linear chain pattern generating C(8) and C(9) graph-set motifs, respectively.

4-(4-Meth-oxy-phen-yl)-6-methyl-amino-5-nitro-2-phenyl-4H-pyran-3-carbonitrile.

In the title compound, C20H17N3O4, the central pyran ring adopts a boat conformation with the O atom and diagonally opposite C atoms displaced by 0.1171 (1) and 0.1791 (1) Å, respectively, from the mean plane defined by the other four atoms. The coplanar atoms of the pyran ring and the meth-oxy-benzene ring are nearly perpendicular, as evidenced by the dihedral angle 87.01 (1)°. The amine H atom forms an intra-molecular N-H⋯O(nitro) hydrogen bond. In the crystal, mol-ecules are linked into dimeric aggregates by N-H⋯O(nitro) hydrogen bonds, generating an R2(2)(12) graph-set motif.

5''-(2,4-Dichloro-benzyl-idene)-1'-(2,4-dichloro-phen-yl)-1''-methyl-1',2',3',5',6',7',8',8a'-octa-hydro-dispiro-[acenaphthyl-ene-1,3'-indolizine-2',3''-piperidine]-2,4''(1H)-dione.

In the title compound, C(37)H(30)Cl(4)N(2)O(2), the pyridinone ring adopts a twisted half-chair conformation. In the octa-hydro-indolizine fused-ring system, the piperidine ring is in a chair conformation and the pyrrole ring is twisted about the C-N bond linking the five- and six-membered rings. The mol-ecular structure features an intra-molecular C-H⋯O inter-action and the crystal packing is stabilized by C-H⋯π inter-actions.

(±)-trans-5-Benzoyl-4-(3-bromo-phen-yl)-2-(1H-indol-3-yl)-4,5-dihydro-furan-3-carbonitrile.

The furan ring in the title compound, C(26)H(17)BrN(2)O(2), adopts a twisted envelope conformation. The mol-ecular structure is stabilized by an intra-molecular C-H⋯O inter-action which generates an S(6) ring motif. The crystal packing is stabilized by N-H⋯O and C-H⋯Br inter-actions, generating an R(2) (2)(16) ring motif and a C(12) linear chain motif, respectively. Weak C-H⋯π bonding is also observed.

Intermolecular C-H···O and C-H···X interactions in substituted spiroacenaphthylene structures.

In the three spiroacenaphthylene structures 5''-[(E)-2,3-dichlorobenzylidene]-7'-(2,3-dichlorophenyl)-1''-methyldispiro[acenaphthylene-1,5'-pyrrolo[1,2-c][1,3]thiazole-6',3''-piperidine]-2,4''-dione, C(35)H(26)Cl(4)N(2)O(2)S, (I), 5''-[(E)-4-fluorobenzylidene]-7'-(4-fluorophenyl)-1''-methyldispiro[acenaphthylene-1,5'-pyrrolo[1,2-c][1,3]thiazole-6',3''-piperidine]-2,4''-dione, C(35)H(28)F(2)N(2)O(2)S, (II), and 5''-[(E)-4-bromobenzylidene]-7'-(4-bromophenyl)-1''-methyldispiro[acenaphthylene-1,5'-pyrrolo[1,2-c][1,3]thiazole-6',3''-piperidine]-2,4''-dione, C(35)H(28)Br(2)N(2)O(2)S, (III), the substituted aryl groups are 2,3-dichloro-, 4-fluoro- and 4-bromophenyl, respectively. The six-membered piperidine ring in all three structures adopts a half-chair conformation, the thiazolidine ring adopts a slightly twisted envelope and the pyrrolidine ring an envelope conformation; in each case, the C atom linking the rings is the flap atom. In all three structures, weak intramolecular C-H···O interactions are present. The crystal packing is stabilized through a number of intermolecular C-H···O and C-H···X interactions, where X = Cl in (I) and F or S in (II), and C-H···O interactions are observed predominantly in (III). In all three structures, molecules are linked through centrosymmetric ring motifs, further tailored through a relay of C-H···X [Cl in (I), Br in (II) and O in (III)] interactions.

5-Benzoyl-2-(1H-indol-3-yl)-4-(4-methyl-phen-yl)-4,5-dihydro-furan-3-carbonitrile.

The furan ring in the title compound, C(27)H(20)N(2)O(2), adopts a twisted conformation about the sp(3)-sp(3) bond. The mol-ecular structure is stabilized by an intra-molecular C-H⋯O inter-action which generates an S(6) ring motif. The crystal packing is stabilized by N-H⋯O and C-H⋯O inter-actions generating centrosymmetric R(2) (2)(18) and C(6) chain motifs, respectively. A weak C-H⋯π inter-action is also observed.

(±)-trans-5-Benzoyl-2-(1H-indol-3-yl)-4-phenyl-4,5-dihydro-furan-3-carbonitrile.

The furan ring in the title compound, C(26)H(18)N(2)O(2), is twisted about the C(H)-C(H) bond. The mol-ecular structure is stabilized by an intra-molecular C-H⋯O inter-action, which generates an S(6) ring motif. The presence of N-H⋯N hydrogen bonds leads to inversion dimers, which are stabilized in the crystal packing by C-H⋯O and C-H⋯π inter-actions, forming layers that stack along the a axis.