Supramolecular imidazolium frameworks: direct analogues of metal azolate frameworks with charge-inverted node-and-linker structure.

While azolate anions have been extensively used as anionic linkers in framework design, we now demonstrate the synthesis of square-grid networks that utilise their cationic analogues, imidazolium ions, as linkers. The resulting imidazolium frameworks are direct hydrogen-bonded analogues of square-grid metal azolates and the first examples of an inverted polarity framework design based on anionic nodes and cationic linkers.