In this work homo- and mixed-valence [2 × 2] grid-like complexes were studied in detail. Here, the multifunctionality features of these iron and cobalt grids are clearly illustrated in properties: 1) the electrochemistry of the metal centers and ligands, which provide a range of redox levels; 2) the magnetism of metal centers, in which the spin state may be influenced not only by the substitution of ligands but also by the structure of complexes; 3) the redox processes are able to change not only the oxidation state but also the spin state of the metal centers, which can enrich the functionality of grid structures. Therefore the understanding of properties in the solid state and solution state of these compounds has been improved.
