Geometry and magnetic interaction modulations in dinuclear Dy2 single-molecule magnets

Abstract

Geometry and magnetic interaction modulations in a series of dinuclear dysprosium compounds, [Dy₂Lz₂(OAc)₆]·2CH₃OH (1), [Dy₂Lz₂(C₆H₅CO₂)₆]·2CH₃CN (2), and [Dy₂L₂(SO₃CF₃)₄THF₄] (3) (Lz = 6-pyridin-2-yl-[1,3,5]triazine-2,4-diamine; L = N-(2,3-dimethylbut-3-en-2-yl)-N-hydroxynitrous amide; THF = tetrahydrofuran), can effectively tune the relaxation dynamics of magnetization. The dysprosium centres of compounds 2 and 3 display a hula hoop-like geometry; however, those in 1 show the monocapped square antiprismatic geometries. Moreover, the Dy₂ cores of compounds 1 and 3 were linked by μ₂–η¹:η¹ and μ₂–η¹:η² bridging modes, thus generating shorter intramolecular Dy⋯Dy distances as compared to those in compound 2. Consequently, these three compounds demonstrate distinct magnetic properties. Compounds 1 and 2 behave as single-molecule magnets (SMMs) under an appropriate static dc field; in addition, 2 displays field-induced multiple relaxation processes under a 1000 Oe dc field. Compound 3 shows a high relaxation energy barrier of 102 K in the zero dc field. These three interesting compounds with Dy₂ cores shed light on the coordination geometry and magnetic interactions for the modulation of the properties of SMMs.