通过Cp(2) LnH d(0) 复合体对H--H激活的DFT研究
1Laboratoire de Structure et Dynamique des Systèmes Moléculaires et Solides (UMR5636), Université de Montpellier 2, 34095 Montpellier Cedex 05, France.
Journal of the American Chemical Society
|July 18, 2001
概括
兰化物复合物的H-H键的激活能量很低,这表明反应很容易. 兰化物电子阴性影响这种能量,而西格玛键转化是反应机制.
科学领域:
- 有机金属化学 有机金属化学
- 计算化学计算化学
- 无机化学 无机化学 有机化学
背景情况:
- 在许多催化过程中,H-H键激活是关键步骤.
- 兰化物复合物因其独特的电子特性和潜在的催化应用而越来越多地被研究.
研究的目的:
- 计算Cp(2) LnH复合体中H-H键激活所需的能量.
- 调查影响激活能量的因素,阐明反应机制.
主要方法:
- 使用B3PW91函数的密度函数理论 (DFT) 计算被采用.
- 对于一系列兰坦化复合物的H-H键裂解的激活能被计算出来.
主要成果:
- 计算的激活能量在0.5到8.0kcal/mol之间,表明容易激活H-H键.
- 在其稳定的氧化状态下,兰化物的电负性被确定为与激活能量趋势相关的主要因素.
- 过渡状态几何学具有几乎线性的H(3)(-) 连接体,具有短的H-H距离和强烈的金属-相互作用.
结论:
- 在Cp(2) LnH复合体中,H-H键激活是一种能量可访问的过程.
- 反应通过西格玛键转化机制进行.
- 化金属的电子阴性在调节H-H键激活能量方面起着至关重要的作用.
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