pi-pi stacking interactions: Non-negligible forces for stabilizing porous supramolecular frameworks

Revealing the contribution of pi-pi stacking interactions in supramolecular assembly is important for understanding the intrinsic nature of molecular assembly fundamentally. However, because they are much weaker than covalent bonds pi-pi stacking interactions are usually ignored in the construction of porous materials. Obtaining stable porous materials that are only dependent on pi-pi stacking interactions, despite being very challenging, could address this concern. Here, we present a porous supramolecular framework (pi-1) stabilized only by intermolecular pi-pi stacking interactions. pi-1 shows good thermal and chemical stability not only in various organic solvents but also in aqueous solution in a broad pH range. Furthermore, featuring one-dimensional channels with dangling thiolate groups, pi-1 exhibits excellent Hg2+ removal performance, with adsorption capacity as high as 786.67 mg g(-1) and an adsorption ratio as high as 99.998%. In addition, pi-1 also shows high adsorption selectivity to Hg2+ in the presence of a series of interfering ions.