Slow Magnetic Relaxation in a Dysprosium Metallocene Complex Bearing Equatorial DyIII−P Bonds

Single molecule magnets (SMMs) containing dysprosium-phosphorus bonding are rare due to great challenges in constructing the bonding between hard lanthanide ions and soft phosphorus donors. Here we successfully isolated a novel mononuclear bis-Cp* dysprosium compound, Cp*₂Dy[η-CH(PPh₂)₂]⋅C₇H₈ (1-Dy), via the salt metathesis reactions of Cp*₂Dy(BPh₄) and K[(PPh₂)₂CH] in THF (Cp*=pentamethylcyclopentadienyl). The magnetic investigations indicate its strong SMM behavior evidenced by the open magnetic hysteresis loops below 6 K and the high effective barrier of 300 cm⁻¹. This could be ascribed to weak dative Dy^III−P bonds at equatorial sites in such [Cp₂DyX]-type (X=auxiliary donors) complexes.