化学学报 ›› 1995, Vol. 53 ›› Issue (9): 847-854. 上一篇    下一篇

研究论文

4,4'-联吡啶、吡嗪和咪唑桥联铜、镍配合物的合成和磁性

李明星;徐正;游效曾;陈成刚;陈钧   

  1. 南京大学配位化学研究所;南京大学配位化学国家重点实验室;复旦大学化学系
  • 发布日期:1995-09-15

Synthesis and magnetic properties of Cu(II), Ni(II) complexes bridged by 4,4'-bipyridine, pyrazine and imidazole

LI MINGXING;XU ZHENG;YOU XIAOZENG;CHEN CHENGGANG;CHEN JUN   

  • Published:1995-09-15

合成了六个含氮杂环桥联配合物: [Ni(salal)2(4,4'-bipy)]n、[Ni(Et-dtp)2(4,4'-bipy)]n、[Cu(acac)2(4,4'-bipy)]n、[Cu(TTA)2(pyz)]n、[Cu(TTa)(Im)]n和[Cu(Im)2]n, 用元素分析、IR、MS、ESR和热重分析对它们的结构和性质作了表征。吡嗪配合物的晶体结构显示, 吡嗪配位于拉伸八面体的轴向位置, 桥联Cu(TTA)2形成一维无限链状结构。变温磁化率表明, 4,4'-联吡啶和吡嗪配合物的磁性遵从Curie-Weiss定律, 分子内没有明显的磁交换作用。咪唑配合物中存在着较强的反铁磁性交换作用, 磁交换常数分别为-75和-107cm^-^1。对4,4'-联吡啶、吡嗪和咪唑传递磁交换的性质作了讨论。

关键词: 红外分光光度法, 元素分析, 质谱法, 咪唑, 铜络合物, 热重量分析, 镍络合物, 电子自旋共振, 联吡啶, 磁性

Six-polynuclear complexes bridged by N-heterocycle, of formula [Ni(salal)2(4,4'-bipy)]n, [Ni(Et-dtp)2(4,4'-bipy)]n, [Cu(acac)2(4,4'-bipy)]n、[Cu(TTA)2(pyz)]n, [Cu(TTa)(Im)]n and [Cu(Im)2]n, were synthesized and characterized by elemental analysis, IR, MS, ESR and thermogravimetric analysis, Crystal structure analysis has proved that the complex [Cu(TTA)2(pyz)]n has one-dimensional infinite linear structure. The local coordination geometry around Cu(II) is a distorted octahedron. The variable-temperature magnetic susceptibility determinations show that the magnetic properties of 4,4'-bipyridine and pyrazine bridging complexes obey the Curie-Weiss law. The imidazole complexes have strong antiferromagnetic interactions, the parameters 2J=-75cm^-^1 for [Cu(TTA)(Im)]n and -107cm^-^1 for [Cu(Im)2]n. Magnetic experimental data are discussed in the relation to the structures of 4,4'-bipyridine, pyrazine and imidazole. It is shown that 4,4'-bipyridine is not a good bridge for propagating a magnetic exchange interaction between n=metal ions.

Key words: INFRARED SPECTROPHOTOMETRY, ELEMENTAL ANALYSIS, MASS SPECTROGRAPHY, IMIDAZOLE, COPPER COMPLEX, THERMOGRAVIMETRY, NICKEL COMPLEX, ELECTRON SPIN RESONANCE, BIPYRIDINE, MAGNETISM

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