Reconfigurable four-component molecular switch based on pH-controlled guest swapping.

The four-component ensemble comprising CB[6], beta-CD, and guests 1 and 2 forms complexes CB[6].1H+ and beta-CD.2 at pH < 7 but swaps partners forming complexes CB[6].2 and beta-CD.1 at pH > 13. The intermolecular nature of the switching process suggests application as a basis for stimuli-responsive reconfigurable systems.