Article ID Journal Published Year Pages File Type
1335674 Polyhedron 2013 6 Pages PDF
Abstract

Reaction of [NEt4][(pzTp)FeIII(CN)3], nickel(II) trifluoromethanesulfonate and 4,4,5,5-tetramethylimidazoline-1-oxyl-2-(2′-pyridyl) (IM-2Py) affords {[(pzTp)FeIII(CN)3]2NiII(IM-2Py)2}·2DMF·H2O·0.5Et2O (1) as a bent cyanide-bridged trinuclear complex. As judged from simulations of the magnetic data, the magnetic exchange between the {FeIII2NiII} (S = 2) and both IM-2Py (S = ½) radical ligands are negligible, or in other words, each radical imparts a Curie contribution to the overall paramagnetism of the complex; the best set of parameters are giso = 2.53(5), grad = 2 (fixed), and Jiso/kB = 3.9(1) K. ac susceptibility and M versus H data show that 1 does not exhibit slow relaxation of the magnetization above 1.8 K. Consistent with the magnetic data, we conclude that bent cyanide bridges, an improper alignment of the FeIIILS anisotropy tensors, and/or small IM-2Py ring distortions conspire to bring insufficient magnetic anisotropy to the complex, and prevent observation of single-molecule magnet behavior.

Graphical abstractReaction of [NEt4][(pzTp)FeIII(CN)3], nickel(II) trifluoromethanesulfonate and 4,4,5,5-tetramethylimidazoline-1-oxyl-2-(2′-pyridyl) (IM-2Py) affords {[(pzTp)FeIII(CN)3]2NiII(IM-2Py)2}·2DMF·H2O·0.5Et2O (1) as a bent cyanide-bridged trinuclear complex. As judged from simulations of the magnetic data, the magnetic exchange between the {FeIII2NiII} (S = 2) and both IM-2Py (S = ½) radical ligands are negligible. Consistent with the magnetic data, we conclude that bent cyanide bridges, an improper alignment of the FeIIILS anisotropy tensors, and/or small IM-2Py ring distortions conspire to bring insufficient magnetic anisotropy to the complex, and prevent observation of single-molecule magnet behavior.Figure optionsDownload full-size imageDownload as PowerPoint slide

Related Topics
Physical Sciences and Engineering Chemistry Inorganic Chemistry
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