Crystal structure of 1,4-diethoxy-9,10-anthraquinone

Abstract

The asymmetric unit of the title compound, C18H16O4, contains two crystallographically independent molecules. The anthraquinone ring systems are slightly bent with dihedral angles of 2.33 (8) and 13.31 (9)° between the two terminal benzene rings. In the crystal, the two independent molecules adopt slipped-parallel π-overlap with an average interplanar distance of 3.45 Å, forming a dimer; the centroid–centroid distances of the π–π interactions are 3.6659 (15)–3.8987 (15) Å. The molecules are also linked by C—H...O interactions, forming a tape structure along the a-axis direction. The crystal packing is characterized by a dimer-herringbone pattern.

Keywords

• crystal structure
• 9,10-anthraquinone
• crystallographically independent molecules
• π–π interactions
• C—H...O interactions