3-Methoxy-19-norpentara-1,3,5(10),17(20)-tetraen-21-one

In the title compound, alternatively called 3′-oxo­cyclo­hex-1′-eno-1′,6′:16,17–3-O-methyl­estra-1,3,5(10),16(16H)-tetraen-3-ol, C₂₃H₂₈O₂, the cyclo­hexenone ring is fused to the five-membered ring through the α position at C16. As a result of the ring annelation, the distance between carbonyl and methoxy O atoms [12.994 (2) Å] is much longer than that in estrones or estradiol. The crystal packing is stabilized by C—H...O and C—H...π hydrogen-bonding interactions.

17-Bromo-16-form­yl-3-methoxy­estra-1,3,5(10),16-tetra­ene

In the title estrane derivative, C₂₀H₂₃BrO₂, the five-membered ring adopts a conformation that is inter­mediate between twist and envelope. The C atom of the form­yl group and the bromo function are in close proximity. Close inter­molecular Br...Br and Br...C contacts are observed in the crystal structure.

Bis(4-chloro­methyl-2,5-di­methyl-3-thienyl)­methane

In the title compound, C₁₅H₁₈Cl₂S₂, the mol­ecule has a crystallographic twofold axis. The dihedral angle between the symmetry-related thio­phene rings is 85.54 (8)°.

2,7-Di­bromo-2,4,6-cyclo­heptatrien-1-one (2,7-di­bromo­tropone)

The title compound, C₇H₄Br₂O, has mirror symmetry perpendicular to the tropone ring, and forms a head-to-head association of two nearly parallel mol­ecules. Intermolecular π–π, halogen–halogen and C—H...O interactions are observed in the crystal structure.

2-Amino-5-[4-(octylamino)phen­yl]cyclo­hepta-2,4,6-trien-1-one

The title compound, also known as 2-amino-5-[4-(octylamino)phen­yl]tropone, C₂₁H₂₈N₂O, contains two crystallographically independent mol­ecules in the asymmetric unit. The NH₂ group of the 2-amino­tropone unit and the NH group of the amino­benzene unit participate in inter­molecular hydrogen bonding with the O atoms of neighbouring mol­ecules. An inter­molecular π–π inter­action is observed in the crystal structure.

7-Diethyl­amino-3-dimethyl­amino-2H-1-benzopyran-2-one

In the title compound, C₁₅H₂₀N₂O₂, the N atom of the diethyl­amine group has a planar environment, whereas the N atom of the dimethyl­amine group is pyramidal. Inter­molecular C—H...π and C—H...O inter­actions are observed in the crystal structure.

Bis(4-dodecyl­oxyphen­yl)diazene oxide

The title compound, C₃₆H₅₈N₂O₃, also known as a liquid crystalline material, has a phase sequence of crystal–smectic C–isotropic liquid. The two benzene rings are nearly coplanar with the central NNO group, and each paraffin chain has an all-trans conformation. The mol­ecules form a tilted layer structure via inter­molecular π–π, C—H...O and C—H...π inter­actions.