Polyfluoroarene–arene π–π stacking in three directions to provide crystal polarity

• Orthogonal columns of π–π stacked polyfluoroarenes and arenes in three directions.
• Polar crystal structure.
• Hydrogen- and halogen-bonding between the anions and a chloroform molecule.
• Halogen-bonding between the cations and a chloroform molecule.

1-(4-Chloro-2,3,5,6-tetrafluorophenyl)-3-benzylimidazolium bromide crystallized from chloroform in the polar space group Cc. The geometry of the cation and the presence of a chloroform molecule, which interacts with the cations and anions through hydrogen- and halogen-bonding, leads to π–π stacked columns in three, approximately orthogonal, directions. The crystal polarity arises from the orientation of the cations which is determined by the stacking.

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