Crystal structure of 8-[7,8-bis-(4-chloro-benzo-yl)-7H-cyclo-penta-[a]ace-naphthylen-9-yl]naphthalene-1-carb-oxy-lic acid.

The title compound, C40H22Cl2O4, was formed by a Michael-Aldol domino reaction sequence, which coupled acenaphthene-quinone with 4-chloro-aceto-phenone in the presence of KOH in methanol. The dihedral angles between the central cyclo-penta-[a]ace-naphthyl-ene fused-ring system (r.m.s. deviation = 0.066†à ) and the 4-chloro-benzoyl rings are 62.25†(10) and 70.19†(10)°. The dihedral angle between the central ring system and the naphthoic acid grouping is 62.46†(7)°. This twisting of the pendant rings facilitates the formation of an intra-molecular aromatic π-π stacking inter-action between the 4-chloro-benzoyl and naphthoic acid rings, with centroid-centroid distances of 3.4533†(16) and 3.5311†(16)†à , and a C-H⋯π inter-action between one of the H atoms of the central moiety and the 4-chloro-benzoyl ring with an H⋯π distance of 2.57†à . In the crystal, carb-oxy-lic acid inversion dimers generate R 2 (2)(8) loops. The dimers are linked by weak C-H⋯O and C-H⋯Cl hydrogen bonds and C-H⋯π inter-actions, generating a three-dimensional architecture.