9-[3-(Dimethyl-amino)-prop-yl]-2-trifluoro-meth-yl-9H-thioxanthen-9-ol.

In the title compound, C(19)H(20)F(3)NOS, the dihedral angle between the mean planes of the two benzene rings attached to the thioxanthene ring is 41.8 (7)°; the latter has a slightly distorted boat conformation. The F atoms are disordered over three sets of sites [occupancy ratio = 0.564 (10):0.287 (10):0.148 (5)] and the methyl groups are disordered over two sets of sites [occupancy ratio = 0.72 (4):0.28 (4)]. The crystal packing is stabilized by O-H⋯N and C-H⋯S hydrogen bonds and weak C-H⋯Cg inter-actions.

2,2-Diphenyl-acetamide.

In the title compound, C(14)H(13)NO, which has two mol-ecules in the asymmetric unit, the dihedral angles between the mean planes of the benzene rings are 84.6 (7) and 85.0 (6)°. N-H⋯O hydrogen bonds [forming R(2) (2)(8) ring motifs] and C-H⋯O hydrogen bonds dominate the crystal packing, forming zigzag chains parallel to the a axis. In addition, weak inter-molecular C-H⋯π inter-actions are observed.

Methyl 2-(4-hy-droxy-benzo-yl)benzoate.

In the title compound, C(15)H(12)O(4), the dihedral angle between the benzene rings is 64.0 (6)°. In the crystal, mol-ecules are linked by O-H⋯O hydrogen bonds, forming C(8) chains propagating in [10[Formula: see text]] and the packing is reinforced by weak C-H⋯O inter-actions.

Opipramolium fumarate.

In the crystal structure of the title salt {systematic name: 4-[3-(5H-dibenz[b,f]azepin-5-yl)prop-yl]-1-(2-hy-droxy-eth-yl)piperazin-1-ium (2Z)-3-carb-oxy-prop-2-enoate}, C(23)H(30)N(3)O(+)·C(4)H(3)O(4) (-), the piperazine group in the opipramol cation is protonated at only one of the N atoms. In the cation, the dihedral angle between the two benzene rings is 53.5 (6)°. An extensive array of inter-molecular O-H⋯O, O-H⋯N and N-H⋯O hydrogen bonds and weak inter-molecular N-H⋯O, C-H⋯O and C-H⋯π inter-actions dominate the crystal packing.

2,2-Diphenyl-4-(piperidin-1-yl)butanamide.

In the title compound, C(21)H(26)N(2)O, the dihedral angle between the mean planes of the two benzene rings is 81.1 (9)°. The piperidine ring is in a chair conformation. The crystal packing is stabilized by N-H⋯N and N-H⋯O hydrogen bonds and weak inter-molecular C-H⋯O inter-actions.

Cyclo-benzaprinium chloride.

In the title mol-ecular salt [systematic name: 3-(5H-dibenzo[a,d]cyclo-hepten-5-yl-idene)-N,N-dimethyl-propan-aminium chloride], C(20)H(22)N(+)·Cl(-), two cation-anion pairs make up the asymmetric unit. The dihedral angles between the mean planes of the two fused benzene rings of the cation are 49.5 (1) and 50.9 (1)°. The cystal packing is stabilized by N-H⋯Cl hydrogen bonds and weak C-H⋯Cl inter-actions.

6-{[(Benz-yloxy)carbon-yl]-oxy}-2-methyl-hexa-hydro-pyrano[3,2-d][1,3]dioxin-7,8-diyl bis-(chloro-acetate).

The asymmetric unit of the title compound, C(20)H(22)O(10)Cl(2), consists of a 6-{[(benz-yloxy)carbon-yl]-oxy}group and two chloro-acetate groups bonded to a 2-methyl-hexa-hydro-pyrano[3,2-d][1,3]dioxin group at the carbon 1,2 and 3 positions, respectively, of a pyrano ring fused to a dioxin ring. The dihedral angle between the mean planes of the dioxin and benzyl rings is 42.2 (2)°. An extensive array of weak inter-molecular C-H⋯O hydrogen bonds links the mol-ecules into chains along [011]. Additional weak inter-molecular C-H⋯π inter-actions occur between C-H atoms of the dioxin and benzyl rings and a nearby benzene ring. A MOPAC geometry optimization calculation in vacuo revealed that the dihedral angle between the mean planes of the dioxin and benzyl rings increased by 24.42 to 66.64°, suggesting that the weak inter-molecular hydrogen-bonding inter-actions, in coord-ination with weak C-H⋯π inter-actions, influence the geometry of the resultant crystalline species and help to stabilize the crystal packing.

1-(2-Methyl-5-nitro-phenyl)guanidinium picrate.

In the crystal structure of the title salt, C(8)H(11)N(4)O(2) (+)·C(6)H(2)N(3)O(7) (-), the pictrate anion participates in extensive hydrogen bonding with the guanidinium ion group of the cation, linking the mol-ecules through N(+)-H⋯O(-) hydrogen bonds and inter-molecular N-H⋯O and C-H⋯O inter-actions. These hydrogen-bonding configurations involve two three-centre/bifurcated bonds [N-H⋯(O,O)] that are observed between two N atoms from the guanidinium ion group of the cation and the o-NO(2) and phenolate O atoms of the picrate anion. In addition, π-π inter-actions also contribute to the crystal packing, with a centroid-to-centroid distance of 3.693 (6) Šand a slippage angle of 1.614°. A significant number of conformational differences are observed between the salt in the crystal structure and the models obtained by density functional theory (DFT) calculations of the geometry-optimized structure.

rac-Ethyl 3-(3-bromo-2-thien-yl)-2-oxo-6-(4-propoxyphen-yl)cyclo-hex-3-ene-1-carboxyl-ate.

The racemic title compound, C(22)H(23)BrO(4)S, crystallizes with two mol-ecules in the asymmetric unit. The dihedral angles between the thio-phene and phenyl rings are 71.64 (17) and 73.41 (17)°.

Phthalazin-1(2H)-one-picric acid (1/1).

The geometric parameters of the title compound, C(8)H(6)N(2)O·C(6)H(3)N(3)O(7), are in the usual ranges. The three nitro groups are almost coplanar with the aromatic picrate ring [dihedral angles 10.2 (2)°, 7.62 (16) and 8.08 (17)°]. The mol-ecular conformation of the picric acid is stabilized by an intra-molecular O-H⋯O hydrogen bond. The phthalazin-1(2H)-one mol-ecules are connected via N-H⋯O hydrogen bonds, forming centrosymmetric dimers.

3-[(Z)-(4-Diethyl-amino-6-oxocyclo-hexa-2,4-dien-1-yl-idene)methyl-amino]benzoic acid.

The title compound, C(18)H(20)N(2)O(3), crystallizes as the keto tautomer, unlike the vast majority of similar structures that have been reported that contain the hydr-oxy tautomer. There are two strong hydrogen bonds in the crystal structure, both accepted by the same carbonyl group: one intra-molecular N-H⋯O and one inter-molecular O-H⋯O. As a result, the carbonyl C=O distance is long, at 1.310 (2) Å, which may suggest the mol-ecule has a significant zwitterionic character. The dihedral angle between the benzene ring planes is 15.05 (7)°. As a result of the intramolecular hydrogen bond, the bridging C-C=N-C group is almost coplanar with the benzene ring that has the diethylamino substituent [dihedral angle 2.35 (15)°].

Redetermination of 4-hydroxy-benzaldehyde.

This is a redetermination of the structure of the title compound, C(7)H(6)O(2), which was first reported by Iwasaki [Acta Cryst. (1977 ▶), B33, 1646-1648]. The results are obtained with greater precision in the present study. Crystal packing is stabilized by inter-molecular O-H⋯O inter-actions between the hydroxyl and aldehyde groups which link the mol-ecules into chains in a zigzag pattern along the [110] plane of the unit cell.