Structural and luminescent properties of co-crystals of tetra­iodo­ethyl­ene with two aza­phenanthrenes

Two new co-crystals, tetra­iodo­ethyl­ene–phenanthridine (1/2), 0.5C(2)I(4)·C(13)H(9)N (1) and tetra­iodo­ethyl­ene–benzo[f]quinoline (1/2), 0.5C(2)I(4)·C(13)H(9)N (2), were obtained from tetra­iodo­ethyl­ene and aza­phenanthrenes, and characterized by IR and fluorescence spectroscopy, elemental analysis and X-ray crystallography. In the crystal structures, C—I⋯π and C—I⋯N halogen bonds link the independent mol­ecules into one-dimensional chains and two-dimensional networks with subloops. In addition, the planar aza­phenanthrenes lend themselves to π–π stacking and C—H⋯π inter­actions, leading to a diversity of supra­molecular three-dimensional structural motifs being formed by these inter­actions. Luminescence studies show that co-crystals 1 and 2 exhibit distinctly different luminescence properties in the solid state at room temperature.