The coordination compound constructed for nitronyl nitroxide radical NIT-Ph-4-Br and Cu II (hfac) 2 (H 2 O) 2 building blocks (NIT-Ph-4-Br = 2-(4-bromo-phenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, hfac = hexafluoroacetylacetonato) was successfully synthesized. The single-crystal X-ray diffraction analyses indicated that the complexes {(NIT-Ph-4-Br) 2 [Cu(hfac) 2 ] 3 } have centrosymmetric five-spin structures consisting of three Cu(II) ions bridged by two nitroxide ligands and that they consist of two types of copper atoms, one with a heavily Jahn–Teller distorted (4 + 2) octahedral coordination (Cu oct ) and hfac in trans -positions and the other with square pyramidal five-coordinated (Cu pyr ) with three hfac oxygen atoms and N–O oxygen atom at the base and the one hfac oxygen atom at the apex. Different geometries of the copper ions are quite important for magnetochemistry. The magnetic susceptibility study of the coordination compound shows strong antiferromagnetic interactions between the metal center and the organic radical.

中文翻译：

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硝酰基氮氧自由基配位铜(II)配合物的合成、晶体结构和磁性

为硝酰基氮氧自由基 NIT-Ph-4-Br 和 Cu II (hfac) 2 (H 2 O) 2 构建单元构建的配位化合物 (NIT-Ph-4-Br = 2-(4-bromo-phenyl)-4 ,4,5,5-四甲基咪唑啉-1-oxyl-3-oxide, hfac = hexafluoroacetylacetonato) 成功合成。单晶 X 射线衍射分析表明配合物 {(NIT-Ph-4-Br) 2 [Cu(hfac) 2 ] 3 } 具有中心对称的五自旋结构，由两个桥接的三个 Cu(II) 离子组成。氮氧化物配体，它们由两种类型的铜原子组成，一种具有严重的 Jahn-Teller 扭曲 (4 + 2) 八面体配位 (Cu oct ) 和 hfac 的转位，另一种具有方锥五配位 (Cu pyr ) 底部有三个 hfac 氧原子和 N-O 氧原子，顶部有一个 hfac 氧原子。铜离子的不同几何形状对于磁化学非常重要。配位化合物的磁化率研究表明金属中心和有机自由基之间存在强烈的反铁磁相互作用。