Acidic proton modulation of a stilbene-based zwitterionic sulfonic acid in the solid state: Mimicking a biological device

Acidic proton modulation of a stilbene-based zwitterionic sulfonic acid in the crystalline state was studied using three amines with different pK _a values. The three organic crystal structures prepared from the intermolecular interactions of the acid with the amines and water were solved by single-crystal X-ray crystallography. These crystals included an ammonium salt and two hydrate crystals. Furthermore, the three generated crystals could mimic three distinct biological systems: a water/proton blockade, a protonated water array, and a one-dimensional water channel.