square-antiprism geometry, the critical difference found in the terminal substituents of the two ligands fine-tunes the local crystal field around Dy centers and the dinuclear molecular structures of 1 and 2. Magnetic investigations unveil that both 1 and 2 display dynamic magnetic relaxation of single-molecule magnet (SMM) behaviour with different energy barriers of 20.9 K for 1 and 72.7 K for 2 under a zero
用不同的取代基的引线2个的同构
配体的利用两个中心对称的Dy III二聚体,即,[
镝2(bfbpen)2(H 2 O)2 ]·2I - (1)和[
镝2(bcbpen)2(H 2 O)2 ]·2I - ·0.5H 2 O(2)(H 2 bfbpen = ñ,ñ ' -双- (2-羟基-5-
氟-苄基) - ñ,ñ ' -双- (
吡啶-2- -甲基(甲基)
乙二胺和H 2 bcbpen = N,N′-双-(2-羟基-5-
氯-苄基)-N,N′-双-(
吡啶-2-基甲基)
乙二胺)。尽管两种化合物中的Dy离子均一地表现出方形反棱镜的几何形状,但在两个
配体的末端取代基中发现的临界差可微调Dy中心和1和2的双核分子结构周围的局部晶体场。磁性调查揭示,这两个1个2的单分子磁体(
SMM)20.9 K中的不同的能量壁垒行为显示动态磁弛豫1和72.7 K中2下一个零直流(DC)场,以及26.9 K为1在1200 Oe直