Metal-Translocation-Coupled Ligand-Binding/Release by Dinuclear Rhodium Sandwich Complexes

Switching the location of metal atoms or ions in a molecule has been of great interest as a behavior of molecular machines. We describe herein that the reversible metal translocation can be coupled with the ligand-binding/release of organometallic complexes. The two rhodium moieties sandwiched between arylpolyene ligands exhibit metal-assembly and disassembly through reversible migration between the arene site and the olefin site, in response to the association and dissociation of additional ligands. This occurs either with bridging or even non-bridging ligands, where the latter involves oxidative π-addition of the unsaturated hydrocarbon binder to the metal moieties. The assembling- and disassembling states were characterized by NMR and X-ray diffraction analysis.