MOLECULAR-LEVEL DESIGN OF A PHOTOINDUCED MAGNETIC SPIN COUPLING SYSTEM - NICKEL NITROPRUSSIDE

Rational design of a magnetic material (nickel nitroprusside) at the m olecular level allowed switching of a spin coupling by means of photoi nduced metal to ligand charge transfer (MLCT). Before irradiation, spi ns on Ni2+ are in a disordered state. An illumination at 375 nm induce s a MLCT from Fe to NO and forms new spins on Fe and NO. The newly app earing spin on Fe orders the spins on the nearest Ni2+ ions around Fe. In other words, one MLCT aligns five spin sources resulting in the fo rmation of magnetic clusters with S = 5. Furthermore, such a photoindu ced spin ordering can be rerandomized by thermal treatment.