Slow Magnetic Relaxation in a Dysprosium Metallocene Complex Bearing Equatorial Dy^III−P Bonds

Abstract 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* 2 Dy[ η ‐CH(PPh 2 ) 2 ]⋅C 7 H 8 ( 1‐Dy ), via the salt metathesis reactions of Cp* 2 Dy(BPh 4 ) and K[(PPh 2 ) 2 CH] 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 [Cp 2 DyX]‐type (X=auxiliary donors) complexes.