Catenanes are an example of an interlocked architecture: two rings that cannot be separated without breaking bonds. Metallo-catananes are a variant made from the combination of metal ions and ligands. These molecules normally exist as an equilibrium between catenated and non-catenated forms. We aim to develop these as molecular machines, switching between forms to turn on or off their capacity to interact, sense, and/or catalytically transform target molecules.