Geometry and magnetic interaction modulations in dinuclear Dy single-molecule magnets.

Geometry and magnetic interaction modulations in a series of dinuclear dysprosium compounds, [DyLz(OAc)]·2CHOH (1), [DyLz(CHCO)]·2CHCN (2), and [DyL(SOCF)THF] (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 Dy cores of compounds 1 and 3 were linked by μ-η:η and μ-η:η bridging modes, thus generating shorter intramolecular DyDy 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 Dy cores shed light on the coordination geometry and magnetic interactions for the modulation of the properties of SMMs.