Interplay of phenyl-perfluorophenyl stacking, C-H...F, C-F...pi and F...F interactions in some crystalline aromatic azines.

Analysis of phenyl-perfluorophenyl stacking synthon, C-H...F, C-F...pi interactions, and F...F tetramer in three closely related azine crystal structures shows the dominance of Ar-ArF synthon while other interactions are turned on/off depending on the H/F stoichiometry in the molecule.