A Coordination Network with Ligand-Centered Redox Activity Based on facial-[CrIII(2-mercaptophenolato)3]3− Metalloligands

5 years ago

A Coordination Network with Ligand-Centered Redox Activity Based on facial-[CrIII(2-mercaptophenolato)3]3− Metalloligands

Masako Kato, Takeshi Matsumoto, Atsushi Kobayashi, Masanori Wakizaka, Ho-Chol Chang

The design of redox-active metal–organic frameworks and coordination networks (CNs), which exhibit metal- and/or ligand-centered redox activity, has recently received increased attention. In this study, the redox-active metalloligand (RML) [Me4N]3fac-[CrIII(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 [K3fac-{CrIII(mp)3}(H2O)6]n (2⋅6 H2O), 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⋅6 H2O in the solid state. The facbook network: This study shows that the redox-active metalloligand fac-[CrIII(2-mercaptophenolato)3]3− coordinates to K+ ions through its three-directional O/S sites to form a 2D honeycomb-like coordination network, which exhibits ligand-centered redox properties in the solid state.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201701613