Crystal structure of 2,2'-bi-pyridine-1,1'-diium tetra-chlorido-zincate.

In the crystal structure of the title salt, (C10H10N2)[ZnCl4], the bi-pyridine-diium dication is not planar, with a dihedral angle of 37.21 (9)° between the planes of the two pyridine rings. In the crystal, the slightly distorted [ZnCl4](2-) anions are packed into rods parallel to [001], with the organic cations arranged in corrugated layers parallel to (100). Cations and anions are linked through N-H⋯Cl hydrogen bonds, forming chains parallel to [20-1]. Additional C-H⋯Cl inter-actions consolidate the crystal packing.

Ethyl 8''-chloro-1'-methyl-2,12''-dioxo-12''H-di-spiro-[indoline-3,2'-pyrrolidine- 3',6''-indolo[2,1-b]quinazoline]-4'-carboxyl-ate.

In the title compound, C29H23ClN4O4, the quinazoline-indole system and the indolin-2-one system are each essentially planar, with maximum deviations from their mean planes of 0.150 (2) and 0.072 (2) Å, respectively. The central pyrrolidine ring adopts a twisted conformation on the C-C bond involving the spiro C atoms. Its mean plane forms dihedral angles of 83.37 (9) and 86.56 (8)°, respectively, with the indole rings of the indolin-2-one and quinazoline-indole systems. In the crystal, mol-ecules are linked via pairs of N-H⋯O hydrogen bonds, forming inversion dimers. The dimers are linked via C-H⋯O hydrogen bonds, forming chains propagating along [001].

Ethyl 1''-benzyl-1'-methyl-2''-oxodi-spiro-[indeno-[1,2-b]quinoxaline-11,3'-pyrrolidine-2',3''-indoline]-4'-carboxyl-ate.

In the title compound, C36H30N4O3, the quinoxaline-indene system is roughly planar, with a maximum deviation from the mean plane of 0.218 Šfor the C atom shared with the central pyrrolidine ring. This latter ring forms dihedral angles of 84.54 (7) and 83.91 (8)° with the quinoxaline-indene system and the indole ring, respectively. The central pyrrolidine ring has an envelope conformation with the N atom as the flap, while the pyrrolidine and five-membered rings of the indole group adopt twisted conformation and envelope (with the C atom bearing the quinoxaline-indene system as the flap) conformations, respectively. In the crystal, mol-ecules are linked via weak C-H⋯N hydrogen bonds, forming a chain running along [100].

Methyl (3S,10b'S)-5-chloro-9'-fluoro-1-methyl-2-oxo-5'-phenyl-10b'H-spiro-[indoline-3,1'-pyrazolo-[3,2-a]iso-quinoline]-2'-carboxyl-ate.

In the title compound, C27H19ClFN3O3, the pyrazole ring has a twist conformation and the six-membered ring to which it is fused has a screw-boat conformation. The mean plane of the pyrazole ring is inclined to the 2-methyl-indoline ring by 85.03 (9) and by 28.17 (8)° to the mean plane of the iso-quinoline ring system. In the crystal, mol-ecules are linked by pairs of C-H⋯F hydrogen bonds, forming inversion dimers. These dimers are linked via C-H⋯O hydrogen bonds, forming a two-dimensional network lying parallel to (10-1).

Methyl 5''-chloro-1',1''-dimethyl-2,2''-dioxodi-spiro-[indoline-3,2'-pyrrolidine-3',3''-indoline]-4'-carboxyl-ate.

In the title compound, C22H20ClN3O4, the central pyrrolidine ring adopts an envelope conformation on the N atom. The indolinone systems are individually roughly planar, with maximum deviations from their mean planes of 0.130 Šfor the spiro C atom of the indolinone unit and 0.172 Šfor the carbonyl C atom of the 5-chloro-1-methyl-indolinone unit. They make dihedral angles of 77.7 (8) and 86.1 (8)° with the mean plane through the central pyrrolidine ring. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds supported by C-H⋯O contacts into chains along the ab diagonal. The structure also features C-H⋯O hydrogen bonds, forming R 2 (2)(8) and R 2 (2)(16) rings and generating a three-dimensional array.

Ethyl 1''-benzyl-2''-oxo-2',3',5',6',7',7a'-hexa-hydro-1'H-di-spiro-[indeno-[1,2-b]quinoxaline-11,2'-pyrrolizine-3',3''-indoline]-1'-carboxyl-ate monohydrate.

In the title compound, C38H32N4O3·H2O, the quinoxaline-indene and pyrrolizine systems are essentially planar, with maximum deviations from their mean planes of 0.162 and 0.563 Å, respectively. The pyrrolizine ring forms dihedral angles of 88.53 (5) and 89.95 (8)° with the quinoxaline-indene system and the indoline ring, respectively. The central pyrrolidine ring has an envelope conformation with the C atom bearing the quinoxaline-indene system as the flap. The pyrrolidine ring of the indole system adopts an envelope conformation with the C atom bonded to the pyrrolizine ring N atom as the flap. The five-membered ring attached to the central pyrolidine ring adopts a twisted conformation. In the crystal, O-H⋯N and O-H⋯O hydrogen bonds between water mol-ecules and pyrrolizine N and carbonyl O atoms together with C-H⋯O inter-actions result in chains along [100].

6'-(1,3-Diphenyl-1H-pyrazol-4-yl)-7'-(1H-indol-3-ylcarbon-yl)-2-oxo-1-(prop-2-en-1-yl)-5',6',7',7a'-tetra-hydro-1'H-spiro-[indoline-3,5'-pyrrolo-[1,2-c][1,3]thia-zole]-7'-carbo-nitrile.

In the title compound, C41H32N6O2S, the pyrrolo-thia-zole ring system is folded about the bridging N-C bond. The thia-zolidine and pyrrolidine rings adopt envelope (with the fused C atom as the flap) and twisted conformations, respectively. The two phenyl rings attached to the pyrazole ring are twisted from the plane of the latter by 6.8 (1) and 52.8 (1)°. The allyl group is disordered over two conformations in a 0.805 (6):0.195 (6) ratio. In the crystal, pairs of N-H⋯O hydrogen bonds link the mol-ecules into centrosymmetric dimers.

A diastereomer of methyl (1R,3'S)-1',1''-dimethyl-2,2''-dioxo-2H-dispiro-[ace-naphthyl-ene-1,2'-pyrrolidine-3',3''-indoline]-4'-carboxyl-ate.

In the title compound, C26H22N2O4, the central pyrrolidine ring adopts a twist conformation and the cyclo-pentane ring of the dihydro-acenapthylene group adopts an envelope conformation with the spiro C atom as the flap. The naphthalene ring system of the dihydro-acenaphthyl-ene group forms dihedral angles of 83.4 (9) and 61.3 (7)°, respectively, with the mean planes of the pyrrolidine and indole rings. The crystal packing is stabilized by inter-molecular C-H⋯O hydrogen bonds. The title compound is a diastereomer of a previously reported structure.

(3E)-11,16-Dioxatricyclo-[15.4.0.0(5,10)]henicosa-1(21),3,5,7,9,17,19-heptaen-2-one.

The title compound, C19H18O3, crystallizes with three mol-ecules (A, B and C) in the asymmetric unit. The carbonyl O atom shows positional disorder over two sites in mol-ecules A and B; the site-occupancy ratios are 0.76 (3):0.24 (3) and 0.86 (3):0.14 (3), respectively. The ethyl-ene fragments in each mol-ecule have an E conformation, while the C-O-C-C torsion angles indicate near planarity. The dihedral angles formed by the aromatic rings are 20.0 (1), 23.7 (1) and 16.1 (1)° for mol-ecules A, B and C, respectively. Intra-molecular C-H⋯O hydrogen bonds occur in each mol-ecule.

3,3'-(p-Phenyl-ene)bis-(3,4-dihydro-2H-1,3-benzoxazine).

Mol-ecules of the title compound, C(22)H(20)N(2)O(2), are situated on crystallographic centres of symmetry. The oxazinane ring adopts a sofa conformation. Mol-ecules are linked into cyclic centrosymmetric dimers via C-H⋯O hydrogen bonds with the motif R(2) (2)(6). In addition to the C-H⋯O inter-actions, the crystal structure is also stabilized by C-H⋯π inter-actions.