控制地将ME8(n-) 双离子 (M = Cr,Mo;E = As,Sb) 聚合成一维数组:结构,磁性和光谱学
Banu Kesanli1, James Fettinger, Bryan Eichhorn
1Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA.
Journal of the American Chemical Society
|June 12, 2003
概括
新的过渡金属集群具有冠状的循环-E(8) 环被合成和特征. 这些新型化合物表现出多样化的结构安排和电子特性,为Zintl-Klemm形式主义和磁性行为提供了洞察力.
科学领域:
- 无机化学 无机化学 有机化学
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
背景情况:
- 辛特离子代表了一个有趣的聚离子集群类,具有独特的结合特性.
- 具有主要组元素的过渡金属复合体因其多样化的电子和结构性质而引起兴趣.
- 了解影响延伸结构与离散离子组装的因素在协调化学中至关重要.
研究的目的:
- 为了合成和描述新型过渡金属含有Zintl类型的[ME(8)](n) ((-).
- 研究这些新化合物的结构,电子和磁性特性.
- 探索支配一维链与孤立离子形成的因素.
主要方法:
- 从Zintl前体和金属复合物中合成[ME(8) ](n) ((-) 离子 (M = Cr,Mo;E = As,Sb;n = 2,3).
- 使用紫外线光谱学,EPR,循环电压测量,磁性易感性,电喷式质谱学 (ESI-MS) 和单晶X射线衍射的表征.
- 结构分析侧重于由过渡金属中心的冠状循环-E(8) 环.
主要成果:
- 在20-45%的晶体产量中成功合成了[ME(8) ](n) ((-) 复合物及其金属盐.
- 观察到结构的多样性,其中一些形成一维链 (例如,K(+) CrAs的盐(8)(3)(-)) 和其他存在于"自由离子".
- 描述揭示了二磁性 (16e(-)) 和二磁性 (17e(-)) 复合物,EPR数据表明某些化合物中的Cr(5+) 中心.
结论:
- 该研究提出了新的过渡金属中心循环-E(8) 集群,具有可调节的电子和结构性质.
- 与自由离子相比,1D链的形成受到诸如 counterion 和金属标识等因素的影响.
- 这些发现有助于理解Zintl-Klemm形式主义和d(1) 过渡金属中心的磁性行为.
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