Crystal structure of r -1, c -2-dibenzoyl- t -3, t -4-bis(2-nitrophenyl)cyclobutane

The condensation reaction of acetophenone (1-phenylethan-1-one) with 2-nitrobenzaldehyde in the molten state yielded the expected chalcone, ( E )-3-(2-nitrophenyl)-1-phenylprop-2-en-1-one, and, unexpectedly, the title compound, C 30 H 22 N 2 O 6 , which results from the syn head-to-head [2 + 2] cycloaddition of the chalcone. The molecular structure of the dimer shows that the four benzene rings of the substituents are oriented in such a way that potential steric hindrance is minimized, whilst allowing some degree of intermolecular π–π interactions for crystal stabilization. In the molecule, one nitro group is disordered over two positions, with occupancies for each part of 0.876 (7) and 0.127 (7).