Bis[4-(diphenyl­methyl­eneamino)phen­yl]methanone

The title mol­ecule, C₃₉H₂₈N₂O, is a well known dendron used in the synthesis of phenyl­azomethine dendrimers. The central benzophenone core is twisted, as expected, due to hindrance between H atoms: the dihedral angle between core benzene rings is 54.49 (5)°, identical to that of the stable polymorph of benzophenone (56°). For the same reason, phenyl groups substituting imine C atoms make a large dihedral angle, although similar for each imine: 71.83 (6) and 67.64 (5)°. The six aromatic rings in the mol­ecule thus seem to be quite randomly oriented, and such an arrangement is not favorable for efficient stacking inter­actions in the crystal. The same behaviour is observed in the vast majority of diphenyl­imino-containing organics. The low triclinic crystal symmetry may be a consequence of these features.