Generation of Zwitterionic Water Channels: Biszwitterionic Imidazolium Carboxylates as Hydrogen-Bonding Acceptors

Organic crystals containing several types of water channels are generated by clipping water molecules with biszwitterionic imidazolium carboxylates as hydrogen-bonding acceptors. The types of water channels to be generated depend on the size and the shape of the aromatic spacers tethered with two imidazolium carboxylates moieties. Clusters of water tetramers and dimers were obtained from imidazolium carboxylates with phenylene (1) and naphthalene (2) linkers, respectively. The latter showed pseudopolymorphism, affording layers of water hexamers. Imidazolium carboxylate possessing biphenylene linker (3) afforded channels of discrete water tetramers.