1,4-Bis(4-chlorophenylseleno)-2,5-dimethoxybenzene

3-Fluoro-4-(4-hydroxyphenoxy)benzonitrile

The title compound, C₁₃H₈FNO₂, was synthesized from 3,4-difluoro­benzonitrile and hydro­quinone. The dihedral angle between the two aromatic rings is 70.9 (2)°. In the crystal structure, mol­ecules are linked by O—H⋯N hydrogen bonds, forming zigzag chains.

3,3'-Difluoro-4,4'-(p-phenyl-enedi-oxy)dibenzonitrile

The title compound, C(20)H(10)F(2)N(2)O(2), was synthesized from hydro-quinone and 3,4-difluoro-benzonitrile. The centroid of the central aromatic ring is on a crystallographic center of inversion. The dihedral angle between the central and terminal rings is 77.8 (3)°. In the crystal, chains linked by C-H⋯N bond occur.

4-Bromoselenoanisole

The title compound, 1-bromo-4-methyl­seleno­benzene, C₇H₇BrSe, was prepared by methyl­ation of 4-bromo­seleno­phenolate with methyl iodide, and crystals suitable for structure determination were obtained by sublimation. The mol­ecule is essentially planar; the Se—Me bond is rotated by only 2.59 (19)° out of the least-squares plane of the benzene ring. The most pronounced intermolecular interactions are two hydrogen bonds of the type C—H⋯π, which determine a herring-bone pattern in the crystal packing.