Development of N,N′-Diaromatic Diimidazolium Cations: Arene Interactions for Highly Organized Crystalline Materials

We applied concepts developed in the context of molecular recognition of aromatic rings in solution to design molecular tectons capable of generating molecular networks based on aromatic stacking in the crystalline phase. In this respect, N,N′-diaromatic diimidazolium cations are interesting tectons because they offer electron-rich (aromatic) and electron-poor (imidazolium) rings able to develop aromatic stacking interactions. Two positive charges and six acidic protons divergently oriented on the diimidazolium dication are involved in strong electrostatic charge−charge interactions and H-bonding with anions. Incorporation of aromatic rings modifies the rigidity of these dications. Depending on the flexibility of the molecules, incorporation of water molecules in the crystal lattice is possible, and channels are created in the solid network.