Ion-pair induced self-assembly in aqueous solvents.

The intriguing advantages of supramolecular chemistry and particularly the application of self-assembly for the construction of defined nanostructures from small, preferably synthetically easily accessible molecules has become a promising area of modern chemistry in the last years. However, the main focus of early work was based on H-bond induced self-assembly which is limited to nonpolar organic solvents. In the past years the field started to shift more and more towards obtaining self-assembling architectures in polar solvents and even water. This tutorial review will discuss some representative examples for self-assembling systems in polar solvents in order to illustrate the different concepts and strategies that can be used. We will also briefly discuss the special properties of water as the ultimate protic solvent from the perspective of a supramolecular chemist to elucidate the challenges that this solvent still poses even today to obtain specific self-assembled nanostructures.