Crystal structure of diethyl 3,3'-[(4-nitro-phen-yl)methyl-ene]bis-(1H-indole-2-carboxyl-ate).

In the title compound, C29H25N3O6, the mean planes of the two indole ring systems (r.m.s. deviations = 0.0115 and 0.0082 Å) are approximately perpendic-ular to one another, making a dihedral angle of 89.7 (5)°; the benzene ring is twisted with respect to the two indole ring systems by 52.6 (4) and 88.2 (3)°. In the crystal, pairs of N-H⋯O hydrogen bonds link the mol-ecules into the inversion dimers, which are further linked into supra-molecular chains along the b-axis direction. Weak C-H⋯O hydrogen bonds and C-H⋯π inter-actions are also observed in the crystal.