Heptanuclear disk-like MII3LnIII4 (M=Ni, Co) coordination clusters: synthesis, structures and magnetic properties

摘要

The synthesis, characterization, crystal structures and magnetic properties of isoskeletal heptanuclear disk-like MII 3LnIII 4 coordination clusters with the general formula [CoII 3LnIII 4(µ3- OH)6L6(CF3SO3)](CF3SO3)5] where Ln= Gd (2), Y (3) and [NiII 3LnIII 4(µ3- OH)6L6(CF3SO3)](CF3SO3)5] where Ln= Dy (4), Gd (5), Y (6) are presented. All the compounds are stable in solution as confirmed by ESI-MS. Magnetic studies were performed for compounds 2, 4, 5 and 6 and indicate ferromagnetic coupling while the magnetocaloric properties of 5 are characterized by ΔSm = -15.4 Jkg-1K -1 at T = 5.0 K and Tad = 5.9 K at T = 2.3 K, for µ0ΔH = 7 T.