Remarkable pi-pi stacking of dipyrido[f,h]quinoxaline-6,7-dicarbonitrile in its ethanol solvate.

The title compound, C16H6N6 x C2H6O, is an ethanol solvate of an aromatic phenanthroline-based flat ligand. The latter exhibits a remarkable pi-pi stacking in the crystal structure, with interplanar distances of 3.27 and 3.40 A, which directs the columnar organization of the ligands. The ethanol solvent molecule is located in channels between these columns, being hydrogen bonded to one of the N-atom sites of the phenanthroline fragment.