Chair-like [Ln^III₄Co^III₂] (Ln = Dy, Eu, Gd, Tb) clusters including a [Dy^III₄Co^III₂] single molecule magnet

Haifeng Zhang^ab,Rui Liu^b,Jin Zhang^a,Yahong Li*^a（李亚红）andWei Liu^a（刘玮）

^aCollege of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China

^bDepartment of Chemistry and Chemical Engineering, Jining University, Qufu 273155, China

CrystEngComm,2016,18, 8246-8252

The employment of a Schiff base ligand 2-((2-(hydroxymethyl)phenylimino)methyl)phenol (H₂L) in the synthesis of Ln^III–Co^IIIclusters is reported. Four isomorphous hexanuclear clusters of compositions [Ln₄Co₂(μ₃-OH)₂(NO₃)₄(CH₃COO)₄L₄(DMF)₂]·2C₂H₅OH [H₂L = 2-((2-(hydroxymethyl)phenylimino)methyl)-6-methoxyphenol; Ln = Dy (1), Eu (2), Gd (3), Tb (4)] have been prepared under solvothermal conditions. The centrosymmetric hexanuclear metallic core is composed of a defect-dicubane Ln₄moiety and two Co^IIIions which are linked to the defect-dicubane unit through two alkoxo groups and two phenoxido groups. This structure gives a chair-like topology. The magnetic properties of1–4were studied. The Dy₄unit of1exhibits slow magnetic relaxation behavior. TheU_efffor1of 41.9 K is a relatively high value among those reported for Dy₄SMMs with defect-dicubane cores. This value is also much higher than those reported for [Dy^III₄Co^III₂] SMMs. This work further illustrates that hydroxide-containing Schiff bases are very effective ligands for designing 3d–4f-based SMMs.

链接：http://pubs.rsc.org/en/content/articlelanding/2016/ce/c6ce01589a#!divAbstract