N¹,N⁴-Diphenyl-3,6-bis­(phenyl­imino)­cyclo­hexa-1,4-diene-1,4-di­amine

In the title compound, C₃₀H₂₄N₄, the central benzo­quinonedi­imine moiety is approximately planar, with a maximum deviation of 0.044 (14) Å. The four terminal phenyl rings are twisted by 44.95 (11), 54.90 (10), 44.98 (10) and 50.68 (11)° with respect to the mean plane the benzo­quinonedi­imine unit. In the crystal, mol­ecules are linked by weak C—H...π inter­actions into supra­molecular chains running along the b-axis direction.

An ortho­rhom­bic polymorph of N¹,N⁴-diphenyl-3,6-bis­(phenyl­imino)­cyclo­hexa-1,4-diene-1,4-di­amine

A new ortho­rhom­bic polymorph of the title compound, C₃₀H₂₄N₄, with a density of 1.315 Mg m⁻³, has been obtained. The mol­ecule is centrosymmetric with the centroid of the cyclo­hexa-1,4-diene ring located on an inversion center. The two unique benzene rings are almost perpendicular to each other [dihedral angle = 86.70 (6)°] and are oriented at dihedral angles of 30.79 (5) and 68.07 (5)° with respect to the central cyclo­hexa­diene ring. In the crystal, π–π stacking is observed between the central cyclo­hexa-1,4-diene-1,4-di­amine unit and a phenyl ring of a neighboring mol­ecule [centroid–centroid distance = 3.7043 (7) Å]. The crystal structure of the triclinic polymorph [Ohno et al. (2014). Acta Cryst. E70, o303–o304] showed chains running along the b-axis direction through weak C—H...π inter­actions.