Switching of the redox centers of a tris-2-mercaptophenolato chromium(III) metalloligand by a guest metal ion.

This work reports that the redox-active metalloligand (ML) fac -[Cr III (mp) 3 ] 3- (mp: 2-mercaptophenolato) coordinates with a Co(III) ion to afford the trianionic complex [Co III { fac -Cr III (mp) 3 } 2 ] 3- . The free ML shows ligand-centered redox processes, whereas the guest-metal-bound trinuclear structure exhibited a guest-metal-centered Co(II)/Co(III) redox couple, demonstrating redox switching through guest-metal binding to the MLs.