双核复合体中持久基的形成和反应性
Aaron M Appel1, Suh-Jane Lee, James A Franz
1Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, USA.
Journal of the American Chemical Society
|June 21, 2008
概括
这项研究探讨了一种特定的硫复合物的反应性. 研究人员确定了原子抽象和激素二元化的动力学,揭示了对硫化学的洞察力.
科学领域:
- 有机金属化学 有机金属化学
- 协调化学 协调化学
- 反应动力学反应动力学
背景情况:
- 在有机硫复合体中的S-H键表现出独特的反应性.
- 了解激素形成和二元化对于催化应用至关重要.
研究的目的:
- 为了研究Cp*Mo(mu-S) 2 ((mu-SMe) ((mu-SH) MoCp* (S4MeH) 的原子抽象动力.
- 描述Mo2S4核心的激进二元化平衡和动力学.
- 阐明涉及硫复合物的反应途径.
主要方法:
- 用基来抽象原子的温度依赖的动力学研究.
- 电子磁共振 (EPR) 光谱法用于确定根二次元平衡常数.
- 可变温度 1H 核磁共振 (NMR) 谱学用于研究二分体解离动力学.
- 射线晶体学用于关键复合物的结构确定.
主要成果:
- 通过基的原子抽象产生了一个速率常数1.3 x 10^6 M^-1 s^-1 在25°C.
- 独家的激素终结产品是基交叉终结产品 (S4MeBz),与持续的激素效应一致.
- 根基 (S4Me*) 可逆二元化,形成一个四核复合体 ((S4Me) 2),其平衡常数为5.7 x 10^4 M^-1.
- 分离率常数为1.1 x 10^3 s^-1,根基分离率常数估计为6.5 x 10^7 M^-1 s^-1.
结论:
- 这项研究提供了对Mo2S4核心中S-H键反应性的全面的动力学和机械学理解.
- 证据支持Mo2S4核心的激进添加/消除途径.
- 关键中间体和产品的结构数据为反应机制提供了洞察力.
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