Pillar[5]arene decaamine: synthesis, encapsulation of very long linear diacids and formation of ion pair-stopped [2]rotaxanes.

A pillar[5]arene decaamine has been synthesized and revealed to encapsulate linear diacids in neutral, alkaline, and acidic conditions, driven by the hydrophobic and electrostatic interactions, to give rise to pseudo[2]rotaxanes. Ion pair-bonded stoppers can further lock the diacids to generate stable water soluble [2]rotaxanes. © The Royal Society of Chemistry 2011