Six-coordinated dinuclear lanthanide(III) amide complexes: investigation of magnetization relaxation dynamics and their electronic structures.

A series of rare six-coordinated dinuclear Ln(III) complexes [Ln2(μ-Cl)2Cl4Li2(L)2(THF)6] were structurally characterized using a bulky amide ligand (L; Ln = Gd(1), Dy(2) and Y(3)). Detailed magnetic studies disclose that a weak antiferromagnetic coupling exists within 1 (-0.09 cm-1) and 2 (-0.07 cm-1; -2J Hamiltonian). Additionally, this study unveils the importance of the amide ligand at the coordination site of Dy(III), which manifests a slow relaxation of magnetization in the absence of an external magnetic field. This has been rationalized by detailed ab initio calculations as well as the electronic structure determination of 1 and 2.