R. Vishnupriya

Crystal structure of 2-(2-bromo­phen­yl)-4-(1H-indol-3-yl)-6-(thio­phen-2-yl)pyridine-3-carbo­nitrile

In the title compound, C24H14BrN3S, the dihedral angles between the planes of the pyridine ring and the pendant thiophene ring, the indole ring system (r.m.s. deviation = 0.022 Å) and the bromobenzene 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 intramolecular C—H⋯N interactions. 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.

4-(4-Fluoro­phen­yl)-6-methyl­amino-5-nitro-2-phenyl-4H-pyran-3-carbo­nitrile

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 fluorophenyl ring are nearly perpendicular, as evidenced by the dihedral angle of 87.11 (1)°. The amine group forms an intramolecular N—H⋯O(nitro) hydrogen bond. In the crystal, molecules 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.

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 cyclooctane ring adopts a twisted boat chair conformation. In the crystal, weak intermolecular C—H⋯π interactions between inversion-related molecules result in the formation of linear double chains along the b-axis direction.

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 cyclooctene 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 fluorobenzene ring are disordered, with occupancy factors of 0.226 (5) and 0.774 (5). In the crystal, no significant interactions are observed between the molecules beyond van der Waals contacts.

5-Benzoyl-2-(1H-indol-3-yl)-4-(4-methyl­phen­yl)-4,5-dihydro­furan-3-carbonitrile

The furan ring in the title compound, C27H20N2O2, adopts a twisted conformation about the sp 3—sp 3 bond. The molecular structure is stabilized by an intramolecular C—H⋯O interaction which generates an S(6) ring motif. The crystal packing is stabilized by N—H⋯O and C—H⋯O interactions generating centrosymmetric R 2 2(18) and C(6) chain motifs, respectively. A weak C—H⋯π interaction is also observed.

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

The furan ring in the title compound, C26H18N2O2, is twisted about the C(H)—C(H) bond. The molecular structure is stabilized by an intramolecular C—H⋯O interaction, 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 interactions, forming layers that stack along the a axis.

(±)-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, C26H17BrN2O2, adopts a twisted envelope conformation. The molecular structure is stabilized by an intramolecular C—H⋯O interaction which generates an S(6) ring motif. The crystal packing is stabilized by N—H⋯O and C—H⋯Br interactions, generating an R 2 2(16) ring motif and a C(12) linear chain motif, respectively. Weak C—H⋯π bonding is also observed.

Crystal structure of 2-(4-chloro­phen­yl)-4-(1H-indol-3-yl)-6-phenyl­pyridine-3-carbo­nitrile

In the title compound, C26H16ClN3, the dihedral angles between the central pyridine ring and the pendant phenyl, chlorobenzene and indole rings are 18.52 (12), 48.97 (11) and 21.20 (10)°, respectively. An intramolecular 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.

5′′-(4-Meth­oxy­benzyl­idene)-7′-(4-meth­oxy­phen­yl)-1′′-methyl-5′,6′,7′,7a'-tetra­hydro­dispiro­[acenaphthene-1,5′-pyrrolo­[1,2-c][1,3]thia­zole-6′,3′′-piperidine]-2,4′′-dione

In the title compound, C37H34N2O4S, the piperidine ring adopts a half-chair conformation. The thiazole ring adopts a slightly twisted envelope conformation and the pyrrole ring adopts an envelope conformation; in each case, the C atom linking the rings is the flap atom. An intramolecular C—H⋯O interaction is noted. The crystal structure is stabilized by C—H⋯O and C—H⋯π interactions.

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.