The crystal structure of the mixed azine C15H9F5N2O is described. The molecule has a high degree of planarity. The two phenyl rings deviate from perfect planarity by less than 2° and the dihedral angles between the ipso-C atoms and the azine bridge also show a minute deviation from planarity of less than 2°. The only dihedral angle that indicates any significant twisting is the dihedral angle about the azine bridge [C1-N1-N2-C8 174.8 (6)°], and even this one is relatively small. Face-to-face arene-arene contacts are the dominant intermolecular interactions. There are double face-to-face contacts in which the two phenyl rings of one mixed azine interact with the two phenyl rings of another mixed azine. There are also single face-to-face contacts where one phenyl ring of one mixed azine interacts with a phenyl ring of another mixed azine. In the double face-to-face arene-arene contacts, the pentafluorinated phenyl ring of one mixed azine always interacts with the methoxy-substituted phenyl ring of another mixed azine. In the single face-to-face arene-arene contacts, the interactions are always between two pentafluorinated phenyl rings or two methoxy-substituted phenyl rings.