1,10-Phenanthroline-5,6-dione ethanol monosolvate.

In the title compound, C12H6N2O2·C2H5OH, the mol-ecule of the 1,10-phenanthroline-5,6-dione is approximately planar, with a maximum deviation of 0.051†(1)†à . In the crystal, mol-ecules are linked by O-H⋯N and weak C-H⋯O hydrogen bonds, forming supra-molecular chains propagating along [110]. π-π stacking inter-actions are observed between the pyridine rings of neighbouring chains, the centroid-centroid separations being 3.6226†(11) and 3.7543†(11)†à .