Strong Exchange and Magnetic Blocking in N 2 3− -Radical-bridged Lanthanide Complexes

Single-molecule magnets approach the ultimate size limit for spin-based devices. These complexes can retain spin information over long periods of time at low temperature, suggesting possible applications in high-density information storage, quantum computing and spintronics. Notably, the success of most such applications hinges upon raising the inherent molecular spin-inversion barrier. Although recent advances have shown the viability of lanthanide-containing complexes in generating large barriers, weak or non-existent magnetic exchange coupling allows fast relaxation pathways that mitigate the full potential of these species. Here, we show that the diffuse spin of an N 2 3− radical bridge can lead to exceptionally strong magnetic exchange in dinuclear Ln( III ) (Ln = Gd, Dy) complexes. The Gd( III ) congener exhibits the strongest magnetic coupling yet observed for that ion, while incorporation of the high-anisotropy Dy( III ) ion gives rise to a molecule with a record magnetic blocking temperature of 8.3 K at a sweep rate of 0.08 T s −1 .