Crystal structures of 2,5-di­azido-1,4-phenyl­ene di­acetate and 2,5-di­azido-1,4-phenyl­ene dibutyrate

2,5-Di­azido-1,4-phenyl­ene di­acetate and dibutyrate are the first structurally characterized representatives with a trans-di­azido­phenyl­ene entity. Both mol­ecules possess inversion symmetry; however, the compounds crystallize in different crystal systems (triclinic versus monoclinic).

Isotypic crystal structures of 2,6-di­bromo-N,N-bis­(4-nitro­phen­yl)aniline and 2,6-di­chloro-N,N-bis­(4-nitro­phen­yl)aniline

The central ternary N atoms in the isotypic crystal structures of the substituted anilines show no sign of pyramidalization.

Crystal structure of trans-1,4-bis­[(tri­methyl­sil­yl)­oxy]cyclo­hexa-2,5-diene-1,4-dicarbo­nitrile

The mol­ecular structure of the title compound is centrosymmetric. The cyclo­hexa-2,5-diene moiety is exactly planar and has a bond-length distribution characteristic for one pair of double bonds and two pairs of single bonds.

9-(4-Bromo­phen­yl)-9H-carbazole

In the title mol­ecule, C₁₈H₁₂BrN, the 4-bromo­phenyl ring is inclined to the mean plane of the carbazole moiety (r.m.s. devation = 0.027 Å) by 49.87 (5)°. In the crystal, molecules stack along [001] and are linked by C—H...π interactions forming a corrugated two-dimensional network lying parallel to (100).