Significant research has been conducted on molecular ferroelectric materials, including pure organic and inorganic compounds; however, studies on ferroelectric materials based on coordination metal complexes are scarce. Ferroelectric materials based on coordination metal complexes have tunable structures and designs, with coexistence or synergy between the ferroelectric behavior and magnetic properties. Compared to inorganic compounds, few coordination metal complexes exhibit coupling between the magnetic and dielectric properties. Coordination metal complexes with strong coupling between the magnetic and dielectric properties exhibit dielectric permittivity variations under external magnetic fields. Therefore, they have attracted substantial interest for their potential use in magnetoelectric devices. In this review, we discuss recent advances in coordination metal complexes, that exhibit coupled magnetic functionalities and ferroelectricity or dielectric properties, including single‐molecule magnets, electron delocalization systems, and external stimuli responsive compounds.

The cover feature image illustrates the conceptual design of synergetic or coexistence of magnetic and dielectric functionalities in the coordination metal complexes. The coordination metal complexes can exhibit flexibility in their electronic/magnetic state based on the combination of metal ions and the design of organic coordination ligands. This cover image shows that coordination metal complexes have tunable structures and designs, with coexistence or synergy between the ferroelectric behavior and magnetic properties. More information can be found in the Review by Y. Sekine, S. Hayami, and co‐workers.