Head-to-tail square-shaped cyclic hydrogen bonds leading to dimeric aggregates: 1,8-dibenzoyl-2,7-dihydroxynaphthalene and a comparison with its analogous benzoylnaphthalene

Abstract

The title compound, C24H16O4, crystallized with two independent molecules in the asymmetric unit. Both carbonyl groups in these molecules form intramolecular O—H...O=C hydrogen bonds with neighbouring hydroxy groups, affording six-membered cyclic structures. In the crystal, dimeric aggregates arise from two intermolecular O—H...O=C hydrogen bonds between both independent molecules, forming head-to-tail square-shaped cyclic ...O...H...O...H... hydrogen bonds. These dimeric aggregates are connected into layers in thebcplane by intermolecular (naphthalene)C—H...O=C interactions. On the other hand, the analogous compound bearing methoxy groups at the 2- and 7-positions of the naphthalene ring, namely 1,8-dibenzoyl-2,7-dimethoxynaphthalene [Nakaemaet al.(2008).Acta Cryst.E64, o807], forms a three-dimensional molecular networkviaC—H...O=C and π–π interactions between the benzoyl groups. These results show that the intramolecular O—H...O=C hydrogen bonds in the title compound control the orientations of the benzoyl groups and thus promote the formation of the cyclic intermolecular O—H...O=C interactions involving the same donor and acceptor groups in pairs of molecules.