Abstract
The title compound, C23H17N3O, has been previously described in a monoclinic P2(1)/c polymorph with Z = 4 [Asiri, Al-Youbi, Faidallah, Ng & Tiekink (2011). Acta Cryst. E67, o2449]. In the new monoclinic P2(1)/ n form, with Z = 8, there are two independent molecules, A and B, 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)degrees (molecule A) and 30.6 (10)degrees (molecule B). 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)degrees, in A and B respectively]. In the crystal, the two independent molecules self-associate via N-H center dot center dot center dot N hydrogen bonds, generating a 12-membered {center dot center dot center dot HNC3N} 2 synthon. These are connected into a supramolecular tape in the (101) plane by N-H center dot center dot center dot O(methoxy) interactions. In the P2(1)/ c polymorph, supramolecular layers are formed by N-H center dot center dot center dot N and N-H center dot center dot center dot O interactions.