A third polymorph of 1,4-bis­(1H-benzimid­azol-2-yl)benzene

The title compound, C₂₀H₁₄N₄, is a new polymorph of the previously reported structures, which were ortho­rhom­bic, space group Pbca [Bei et al. (2000). Acta Cryst. C56, 718–719] and monoclinic, space group P2₁/c [Dudd et al. (2003). Green Chem. 5, 187–192]. The asymmetric unit consists of two independent mol­ecules in which the dihedral angels between the central benzene ring and the outer benzimidazole ring systems are 16.81 (10) and 14.23 (10)° in one molecule and 26.09 (10) and 37.29 (10)° in the other. In the crystal, mol­ecules are linked by N—H...N and C—H...N hydrogen bonds into a tape running along the c-axis direction.