Reversible Formation of a [2]Catenane through First‐ and Second‐Sphere Coordination

Reversible catenation: A remarkably stable [2]catenane (see picture; Pd turquoise, Cl green) is formed in one step through a combination of first- and second-sphere coordination of a bidentate ligand and the {PdCl2} metal center. The catenated topology of the two rings can be reversibly converted to the non-interlocked macrocyclic products simply by changing the solvent polarity.