Encapsulation enhanced dimerization of a series of 4-aryl-N-methylpyridinium derivatives in water: new building blocks for self-assembly in aqueous media.

The construction of supramolecular systems in aqueous media is still a great challenge owing to the limited sources of building blocks. In this study, a series of 4-aryl-N-methylpyridinium derivatives have been synthesized. They formed very stable host-guest (1:2) complexes with CB[8] in water (binding constants up to 10(14)  M(-2)) with the two guest molecules arranged in a head-to-tail manner and the complexes showed high thermostability, which was revealed by (1) H NMR and UV/Vis spectroscopic studies, ITC, and crystallographic analysis.