A co-crystal of 1,10-phenanthroline with boric acid: a novel aza-aromatic complex

The title compound, C₁₂H₈N₂·2B(OH)₃, is best described as a host–guest complex in which the B(OH)₃ mol­ecules form a hydrogen-bonded cyclic network of layers parallel to the ab plane into which the 1,10-phenanthroline mol­ecules are bound. An extensive network of hydrogen bonds are responsible for the crystal stability. No π-stacking inter­actions occur between the 1,10-phenanthroline mol­ecules.