Solid-state structure and supra-molecular packing of 1,2-bis-(2-phenyl-1H-benzo[d]imidazol-1-yl)diazene.

The title benzimidazole derivative, C26H18N6, which contains two benzimidazole units connected through an azo (N=N) linkage, was isolated as yellow needle-shaped crystals and characterized by single-crystal X-ray diffraction. The compound crystallizes in the monoclinic crystal system (space group: P21 /c) with one mol-ecule in the asymmetric unit. The dominant inter-actions in the crystal are parallel π-π contacts, giving rise to one-dimensional π-stacks along the a-axis direction, with a centroid-to-centroid separation of 3.899 (1) Å, a slippage distance of 1.81 Å, and a slip angle of 27.61°. Within these stacks, two short C-H⋯C contacts of 2.74 Å are observed between adjacent mol-ecules, which may reflect packing constraints. Along the bc plane, the structure comprises two-dimensional ribbons formed by anti-parallel chains. No short inter-planar contacts are observed between neighboring stacks.