Crystal structure of 2-bromo-1,4-dihydroxy-9,10-anthraquinone

In an attempt to brominate 1,4-dipropoxy-9,10-anthraquinone, a mixture of products, including the title compound, C14H7BrO4, was obtained. The molecule is essentially planar (r.m.s. deviation = 0.029 Å) and two intramolecular O—H...O hydrogen bonds occur. In the crystal, the molecules are linked by weak C—H...O hydrogen bonds, Br...O contacts [3.240 (5) Å], and π–π stacking interactions [shortest centroid–centroid separation = 3.562 (4) Å], generating a three-dimensional network