[Fe{13) O{4) F{24) }{OMe}{12) ]{5-]的合成和结构:第一个开的Keggin离子
Avi Bino1, Michael Ardon, Dongwhan Lee
1Department of Inorganic and Analytical Chemistry, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel. bino@vms.huji.ac.il
Journal of the American Chemical Society
|April 25, 2002
概括
研究人员合成了一种新型的铁(III) 基根离子,由13个具有Td对称性的铁原子组成. 磁性研究揭示了这些铁中心之间的强烈相互作用,表明它们具有独特的磁性.
科学领域:
- 无机化学 无机化学
- 材料科学 材料科学 材料科学
- 磁电化学 磁电化学 磁电化学
背景情况:
- 具有独特结构和磁性特性的新型聚氧甲酸盐的合成是一个活跃的研究领域.
- 基基因离子是聚氧甲酸盐的一个成熟的类别,但具有多个偏磁中心的开变体较少见.
研究的目的:
- 为了合成和表征一种具有高对称性的新型含铁Keggin离子.
- 为了研究新合成的复合物的结构和磁性特性.
主要方法:
- 在甲醇中铁化三水和二烯反应的结晶.
- 单晶X射线衍射用于结构确定.
- 测量磁性易感度以探测磁相互作用.
主要成果:
- 成功合成了 (PyH) 5.5 的黄色棕色晶体. [Fe13O4F24(OMe) [12].4H2O.CH3OH.OH. 4H2O.CH3OH. 4H2O.CH3OH. 4H2O.CH3OH. 4H2O.CH3OH.
- 阴离子复合物的特征 [Fe13O4F24(OMe) [12]5- (1) 具有完整的Td对称性,包括13个高旋转d5铁(III) 原子.
- 结构分析显示,一个中心的四面体{FeO4}单元被12个八面体铁原子包围,由甲氧化物和化物联体架构桥梁.
- 磁性易感性研究表明,铁原子之间存在强烈的反铁磁交换相互作用,与未合的中心相比,有效磁矩显著降低 (μeff = 19.3 μB在300 K) 证明了这一点.
结论:
- 已经合成了第一个具有13个铁 (III) 原子和Td对称性的开基金离子的例子.
- 该综合体表现出强烈的分子内磁交换相互作用,导致独特的磁性行为.
- 这一发现为设计基于聚氧金属结构的磁性材料开辟了新的途径.
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