A New Nitronyl Nitroxide Radical as Building Blocks for a Rare S = 13/2 High Spin Ground State 2p-3d Complex and a 2p-3d-4f Chain

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• 作者：Binling Yao ; Zhilin Guo ; Xuan Zhang ; Yue Ma ; Zhenhao Yang ; Qinglun Wang ; Licun Li ; Peng Cheng
• 刊名：Crystal Growth & Design
• 出版年：2017
• 出版时间：January 4, 2017
• 年：2017
• 卷：17
• 期：1
• 页码：95-99
• 全文大小：328K
• ISSN：1528-7505

文摘

A new nitronyl nitroxide radical L (L = 2-(4-(5-methyl-carbonyl-3-pyriyl)benzoxo)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) containing N–O groups and the pyridyl nitrogen group was designed and synthesized as a multidentate ligand to obtain compounds with interesting structures and magnetic properties from 3d or 3d-4f precursors. The reaction of Cu(hfac)₂ and/or Gd(hfac)₃·2H₂O (hfac = hexafluoroacetylacetonate) with L resulted in a rare S = 13/2 high spin ground state Cu^II complex [(Cu(hfac)₂)₇(L)₆] (1) and a Cu^II–Gd^III chain complex [Gd(hfac)₃Cu(hfac)₂(L)₂]_n·0.5CH₂Cl₂ (2). Single crystal X-ray diffraction studies indicate that the N–O groups of the L radicals are all axially bound to Cu^II ions in complex 1, which result in the ferromagnetic exchange between Cu^II and radicals and an S = 13/2 high spin ground state. While adding Gd(hfac)₃ units to the system of Cu(hfac)₂ and L radical, a one dimension chain structure is obtained, and there are ferromagnetic Gd^III-radical interactions and antiferromagnetic radical–radical coupling in the chain.