Chloride triggered reversible switching from a metallosupramolecular [Pd2L4]4+ cage to a [Pd2L2Cl4] metallo-macrocycle with release of endo- and exo-hedrally bound guests

A metallosupramolecular [Pd2L4](4+) cage can be cleanly converted into a [Pd2L2Cl4] metallo-macrocycle upon addition of chloride ions. The process is reversible, treatment of the [Pd2L2Cl4] macrocycle with silver(I) ions regenerates the [Pd2L4](4+) cage. Additionally, it is shown that guest molecules could be released on chloride triggered cage dis-assembly and taken up anew on re-assembly.