Di- and octa-nuclear dysprosium clusters derived from pyridyl-triazole based ligand: {Dy2} showing single molecule magnetic behaviour

Abstract

Two dysprosium aggregates, formulated as [Dy₂(μ-OH)₂(H₂bpte)₂Cl₂(MeOH)₂]Cl₂ (1), and [Dy₈(μ-OH)₈(bpte)₈]·24H₂O (2) (H₂bpte = 1,2-bis(3-(pyridin-2-yl)-1H-1,2,4-triazol-5-yl)ethane), were obtained using solvothermal reactions. Upon changing the metal salt and synthetic reaction conditions, an eight-member {Dy₈} (2) ring was isolated. Complex 1 is centrosymmetric in which two {Dy₂} clusters are connecting to each other through the hydrogen bonding. Complex 2 forms an eight-member Dy^III ring with an inner diameter of 4.5 Å and is the first reported {Dy₈(μ-OH)₈} core in lanthanide-hydroxo clusters. The H₂bpte ligand displays trans,trans- and cis,cis-coordination modes in 1 and 2, respectively. Alternating current (ac) magnetic measurements of both complexes were carried out. In 1, the out-of-phase susceptibilities (χ′′_M) below 9 K confirm the slow relaxation of magnetization, which is a typical characteristic of single-molecule magnets (SMMs).