Progress in magnetic couple system of nitroxide-metal complexes

Metal-radical method is an effective approach to synthesizing magnetic molecular materials. With the development in decades, the study of nitroxide-metal complexes has made great progress in model, theoretical treatment and design of molecules. Several mechanisms of the metal-radical magnetic coupling are discussed. Molecular magnetic project of nitroxide-metal complexes has made fruitful achievements, but crystal magnetic project is difficult to be controlled, and it is a challenge to chemists. The studies on nitronyl nitroxide-metal complexes are summarized. At present, there are three major approaches to increasing the T-c of the metal-radical compounds: ( I ) Searching for nitronyl ligands that can yield 3-D ferro- or ferrimagnetic structures; ( II ) decorating the structure of radicals with the aim to enhance the coordinate capability of radicals; ( III ) grafting polynitroxide radicals as a versatile bridge. The third approach, namely searching for polynitroxide ligand, will serve as a hopeful strategy for exploring higher T-c radical molecule-based magnets.