第14组元素的诺伯尼尔离子
Thomas Müller1, Christian Bauch, Markus Ostermeier
1Institut für Anorganische Chemie der Goethe Universität Frankfurt, Marie Curie-Strasse 11, D-60439 Frankfurt/Main, Federal Republic of Germany. dr.thomas.mueller@chemie.uni-frankfurt.de
Journal of the American Chemical Society
|February 20, 2003
概括
合成和特征化了14组元素 (从到) 的新norbornyl. 这些体表现出分子内相互作用,稳定性在群体中逐渐增加,为元素结合和反应性提供了洞察力.
科学领域:
- 有机金属化学 有机金属化学
- 碳化物化学 碳化物化学
- 频谱学是一种光谱学.
背景情况:
- 诺伯尼尔是有机反应中重要的中间体.
- 了解14组元素的电子性质对于开发新材料和催化剂至关重要.
- 之前的研究已经探讨了和的norbornyl离子,但较重的元素仍然不太受研究.
研究的目的:
- 合成和描述14组元素 (Si,Ge,Sn,Pb) 的新型norbornyl离子.
- 为了研究正电荷元素与远程双键之间的分子内相互作用.
- 在不同的溶剂环境中探索这些的稳定性和反应性.
主要方法:
- 合成替代的3-cyclopentenemethyl前体.
- 在C=C双键 (pi路径) 中,分子内添加过渡.
- 使用核磁共振 (NMR) 光谱学进行识别和表征 ((29) Si, (13) C, (119) Sn, (207) Pb).
- 量子力学计算 (DFT,GIAO/B3LYP) 用于结构,能量和磁性属性分析.
- 用X射线结晶学测定复合物的结构.
主要成果:
- 成功合成并识别了Si,Ge,Sn和Pb (4a,e-i) 的norbornyl离子.
- 核磁共振数据和合常数提供了分子内相互作用和电荷转移的证据.
- 计算证实了与元素原子3+1协调的桥梁norbornyl离子结构.
- 稳定性从Si增加到Pb,plumbanorbornyl离子表现出显著的稳定性.
- 乙酸溶剂分解Si-Sn的分子内相互作用,但与Pb (10i) 形成稳定的复合物.
结论:
- 14组的诺博尼尔可以通过PI路径有效合成.
- 元素与双键之间的分子内相互作用是显著的,并且依赖于元素.
- 热力学稳定性在该组下方增加,而分子内稳定能降低.
- 对于像乙尼特里尔这样的核友的反应性有很大的变化,表现出独特的复杂化行为.
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