A second monoclinic polymorph for 3-amino-1-(4-methoxyphenyl)-9,10-dihydrophenanthrene-2,4-dicarbonitrile
The title compound, C23H17N3O, has been previously described in a monoclinicP21/cpolymorph withZ= 4 [Asiri, Al-Youbi, Faidallah, Ng & Tiekink (2011).Acta Cryst. E67, o2449]. In the new monoclinicP21/nform, withZ= 8, there are two independent molecules,AandB, in the asymmetric unit. In both molecules, the cyclohexa-1,3-diene ring has a screw-boat conformation, whereas it is a distorted half-chair in the original polymorph. There is a fold in each molecule, as indicated by the dihedral angle between the benzene rings of the 1,2-dihydronaphthalene and aniline residues of 33.19 (10)° (moleculeA) and 30.6 (10)° (moleculeB). The methoxybenzene ring is twisted out of the plane of the aniline residue to which it is connected [dihedral angles = 49.22 (10) and 73.27 (10)°, inAandBrespectively]. In the crystal, the two independent molecules self-associateviaN—H...N hydrogen bonds, generating a 12-membered {...HNC3N}2synthon. These are connected into a supramolecular tape in the (-101) plane by N—H...O(methoxy) interactions. In theP21/cpolymorph, supramolecular layers are formed by N—H...N and N—H...O interactions.