那么,J(Si-H) 的NMR合常数真的是一个探测非经典的H-Si相互作用存在的探针吗?
Stuart R Dubberley1, Stanislav K Ignatov, Nicholas H Rees
1Inorganic Chemistry Laboratory, South Parks Road, Oxford OX1 3QR, UK.
Journal of the American Chemical Society
|January 16, 2003
概括
研究人员合成了的化复合物,并观察到化连接常数随着替代的变化而显著增加. DFT计算显示,这种趋势与债券强度无关,对于n=1.1.而言,相互作用最强.
科学领域:
- 有机金属化学 有机金属化学
- 无机化学 无机化学
- 计算化学的计算化学
背景情况:
- 复合物在催化和材料科学中至关重要.
- 了解金属复合体中的联结体相互作用是预测反应性的关键.
- 二基连接物具有独特的电子和硬质性质.
研究的目的:
- 为了合成和表征一系列的水解复合物.
- 为了研究连接体替代和光谱性质之间的关系.
- 通过计算方法阐明化物和基连接体之间的结合相互作用.
主要方法:
- 合成的Cp (ArN) Ta (PMe3) (H) (SiClnR3-n) 复合物 (n = 0-3). 这种复合物中,Cp (ArN) Ta (Ta) PMe3) (H) (SiClnR3-n) 是一个复合物.
- 使用29Si NMR进行光谱分析.
- 通过X射线衍射进行结构确定.
- 使用密度函数理论 (DFT) 进行量子化学计算.
主要成果:
- 成功制备了一系列水解复合物.
- 观察到J ((Si-H) 合常数的前所未有的增加,随着西联体化增加 (从n=0的14 Hz到n=3的50 Hz).
- DFT计算表明,最强的Si-H结合相互作用发生在n=1时,尽管观察到的合常数趋势.
结论:
- (Si-H) 合常数不是这些复合物的Si-H键强度的直接指标.
- 在基上基替代显著影响光谱参数.
- 计算建模对于准确解释有机金属化合物中的结合相互作用至关重要.
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