A Coordination Network with Ligand-Centered Redox Activity Based on facial-[CrIII(2-mercaptophenolato)_3]_3- Metalloligands

摘要

The design of redox-active metal-organic frameworks and coordination networks (CNs), which exhibit metaland/ or ligand-centered redox activity, has recently received increased attention. In this study, the redox-active metalloligand (RML) [Me_4N]_3 fac-[Cr~(III)(mp)_3] (1) (mp=2-mercaptophenolato) was synthesized and characterized by single-crystal X-ray diffraction analysis, and its reversible ligand-centered one-electron oxidation was examined by cyclic voltammetry and spectroelectrochemical measurements. Since complex 1 contains O/S coordination sites in three directions, complexation with K+ ions led to the formation of the two-dimensional honeycomb sheet-structured [K_3fac-{Cr~(III)(mp)_3}(H_2O)_6]_n (2·6H_2O), which is the first example of a redox-active CN constructed from a RML with o-disubstituted benzene ligands. Herein, we unambiguously demonstrate the ligand-centered redox activity of the RML within the CN 2·6H_2O in the solid state.