Dysprosium Complexes Bearing Unsupported DyIII–GeII/SnII Metal–Metal Bonds as Single-Ion Magnets

Two dysprosium complexes (iPrCp)2DyGePh3(THF) (1DyGe) and (Cp*)2DySnPh3(THF) (1DySn) ([iPrCp]– = isopropylcyclopentadienide; [Cp*]– = pentamethylcyclopentadienide) bearing unsupported Dy–Ge/Sn metal–metal bonds are reported here for the first time with their syntheses, single crystal structures, bonding character and magnetic properties. Natural bond orbital (NBO) analysis revealed that Dy–Ge and Dy–Sn bonds both contain relatively large covalency. Measurements of magnetic dynamics uncovered that they exhibit slow relaxation of magnetization under a zero applied direct current (DC) field with energy barriers of 485 and 620 K respectively and blocking temperatures of 6 K. Through bonding with electropositive metal ions, DyIII centers retain strong uniaxial magnetic anisotropy.