10-Methyl-2-oxo-4-phenyl-2,11-di-hydro-pyrano[2,3-a]carbazole-3-carbo-nitrile.

In the title mol-ecule, C23H14N2O2, the atoms in the carbazole unit deviate from planarity [maximum deviation from mean plane = 0.1018 (8) Å]. The pyrrole ring makes dihedral angles of 4.44 (5), 3.84 (5), 2.18 (5) and 56.44 (5)° with the pyran, fused benzene rings and phenyl ring, respectively. In the crystal, pairs of N-H⋯O hydrogen bonds generate R 2 (2)(14) loops and a C-H⋯N inter-action is also found. Mol-ecules are further linked by a number of π-π interactions [centroid-centroid distances vary from 3.5702 (5) to 3.7068 (6) Å], forming a three-dimensional network.

7-Methyl-1-phenyl-1,10-di-hydro-pyrazolo-[3,4-a]carbazole.

In the title mol-ecule, C20H15N3, the atoms in the carbazole unit deviate from planarity [maximum deviation from mean plane = 0.1082 (15) Å]. The pyrrole ring makes dihedral angles of 3.17 (8)/4.10 (9), 7.20 (9) and 44.62 (9)° with the fused benzene, pyrazole and phenyl rings, respectively. In the crystal, mol-ecules are linked via N-H⋯N hydrogen bonds, forming an infinite chain along [010]. Mol-ecules are further linked by nine π-π [centroid-centroid distances vary from 3.6864 (11) to 3.9802 (11) Å] and one C-H⋯π inter-action, forming a three-dimensional network.

(E)-2-[(Furan-2-yl)methyl-idene]-7-methyl-2,3,4,9-tetra-hydro-1H-carbazol-1-one.

In the title mol-ecule, C(18)H(15)NO(2), the atoms in the carbazole unit deviate from planarity [maximum deviation from mean plane = 0.1317 (12) Å]. The pyrrole ring makes dihedral angles of 1.01 (8) and 18.56 (10)° with the benzene and furan rings, respectively. The cyclo-hexene ring adopts a half-chair conformation. In the crystal, pairs of N-H⋯O hydrogen bonds form an R(2) (2)(10) ring. Mol-ecules are further linked by C-H⋯O and C-H⋯π inter-actions, forming a three-dimensional network.

2-Chloro-7,8,9,10-tetra-hydro-cyclo-hepta-[b]indol-6(5H)-one.

In the title mol-ecule, C(13)H(12)ClNO, the dihedral angle between the benzene and pyrrole rings is 1.38 (9)°. The cyclo-heptene ring adopts a distorted twist chair and sofa conformation. Inter-molecular N-H⋯O hydrogen bonds form an R(2) (2)(10) loop in the crystal packing. Further, weak C-H⋯O and C-H⋯π (involving the benzene ring) inter-actions are found in the crystal structure.

9-Ethyl-N-(3-nitro-benzyl-idene)-9H-carbazol-3-amine.

The title compound, C(21)H(17)N(3)O(2), crystallizes with two mol-ecules in the asymmetric unit. The carbazole groups show relatively small deviations from planarity [maximum displacements from the mean carbazole plane are 0.077 (7) and 0.101 (7) Å]. The dihedral angles between the 3-nitro-benzyl-idene-amine and carbazole groups are 37.9 (1) and 37.0 (1)° in the two mol-ecules.

5-Methyl-7,8,9,10-tetra-hydro-cyclo-hepta-[b]indol-6(5H)-one.

In the title mol-ecule, C(14)H(15)NO, the dihedral angle between the benzene and pyrrole rings is 1.99 (12)°. The cyclo-heptene ring adopts a slightly distorted boat conformation.

8-Methyl-2,3,4,9-tetra-hydro-1H-carbazol-1-one.

In the title compound, C(13)H(13)NO, the dihedral angle between the benzene ring and the fused pyrrole ring is 0.96 (7)°. The cyclohexenone ring adopts an envelope conformation. Inter-molecular N-H⋯O hydrogen bonds form R(2) (2)(10) ring motifs in the crystal structure. Weak C-H⋯π inter-actions involving the benzene ring also occur.

2,5-Dimethyl-7,8,9,10-tetra-hydro-cyclo-hepta-[b]indol-6(5H)-one.

In the title mol-ecule, C(15)H(17)NO, the dihedral angle between the benzene and pyrrole rings is 1.45 (13)°. The cyclo-heptene ring adopts a slightly distorted boat conformation. In the crystal structure, inter-molecular C-H⋯O hydrogen bonds are found.

(E)-2-(Furan-2-yl-methyl-idene)-8-methyl-2,3,4,9-tetra-hydro-1H-carbazol-1-one.

In the title mol-ecule, C(18)H(15)NO(2), the carbazole unit is not planar [maximum deviation from mean plane = 0.236 (2) Å]. The pyrrole ring makes dihedral angles of 1.21 (10) and 16.74 (12)° with the benzene and the furan rings, respectively. The cyclo-hexene ring adopts a half-chair conformation. In the crystal, inversion dimers linked by pairs of N-H⋯O hydrogen bonds generate R(2) (2)(10) loops.

(E)-6-Chloro-2-(furan-2-yl-methyl-idene)-2,3,4,9-tetra-hydro-1H-carbazol-1-one.

In the title compound, C(17)H(12)ClNO(2), the carbazole unit is nearly planar [maximum deviation = 0.052 (1) Å]. The pyrrole ring makes dihedral angles of 1.92 (8) and 4.71 (11)° with the benzene and furan rings, respectively. Inter-molecular N-H⋯O hydrogen bonds form R(2) (2)(10) rings in the crystal structure.