Outer surface interaction to drive cucurbit[8]uril-based supramolecular frameworks: possible application in gold recovery

Q[8]-based honeycomb-like frameworks can be obtained in [AuCl4]−-free aqueous HNO3 solution and aqueous HCl and HNO3 solutions that contain [AuCl4]−. The outer surface interaction of Q[8] with planar inorganic anions [AuCl4]− and NO3− is the main driving force. These frameworks exhibit a high selectivity for imprisoning [AuCl4]− that could establish a process for gold recovery.