Yi-Tao Li

N-[(E)-4-Pyridylmethyl­ene]-4-[(E)-4-(4-pyridylmethyl­eneamino)benz­yl]aniline tetra­hydrate

The title compound, C25H20N4·4H2O, crystallizes with the organic molecule lying on a twofold rotation axis through the methylene bridge C atom; there are also two water molecules in the asymmetric unit. The crystal structure is stabilized by C—H⋯O, O—H⋯O and O—H⋯N hydrogen bonds, linking the water molecules to each other and to the pyridine N atom.

Diethyl 2,6-diisopropyl-4,8-dioxoperhydro-2,3a,4a,6,7a,8a-hexa­azacyclo­penta­[def]fluorene-8b,8c-dicarboxyl­ate

In the title compound, C20H32N6O6, the five-membered imidazolone rings adopt envelope conformations. The six-membered rings are in chair conformations. The crystal packing is stabilized by C—H⋯O hydrogen bonds.

Diethyl 2,6-dicyclo­hexyl-4,8-dioxo-2,2,3,6,7-tetra­hydro-1H,5H-2,3a,4a,6,7a,8a-hexa­azacyclo­penta­[def]fluorene-8b,8c-dicarboxyl­ate

In the title compound, C26H40N6O6, the five-membered rings adopt envelope conformations and the six-membered rings are in chair conformations. The crystal packing is stabilized by C—H⋯O hydrogen bonds.

N,N′-(Oxydi-p-phenyl­ene)diphthalimide

The title compound, C28H16N2O5, is a bis-imide derivative in which two phthalimide units are linked by an oxydi-p-phenylene bridge. The dihedral angle between the planes of the two central benzene rings is 86.1 (4)°. The isoindole groups make dihedral angles of 46.0 (14) and 77.5 (13)° with the attached benzene rings. Intermolecular C—H⋯O hydrogen bonds contribute to the stability of the structure.

N,N'-{[Bis(trifluoro-meth-yl)methyl-ene]di-p-phenyl-ene}diphthalimide.

The molecule of the title compound, C31H16F6N2O4, consists of two phthalimide units linked by a [bis(trifluoromethyl)methylene]di-p-phenylene bridge, with the two halves of the molecule related to each other by a twofold rotation axis. The dihedral angle between the planes of the two central benzene rings is 70.5 (3)°. The terminal isoindole groups are approximately planar, with a maximum r.m.s. deviation of 0.006 Å from the mean plane, and they form dihedral angles of 46.03 (3)° to the attached benzene rings. Intermolecular C—H⋯O hydrogen bonds link neighboring molecules into chains along the c axis.