从值光电子光离子巧合光谱学对金属离子的结合能和异构化
Agnes Révész1, László Szepes, Tomas Baer
1Institute of Chemistry, Eötvös Loránd University, Budapest, Hungary.
Journal of the American Chemical Society
|December 2, 2010
概括
这项研究使用值光电子光离子巧合光谱学来分析金属离子碎片化. 我们确定了金属-cyclopentadienyl键解离能,揭示了与电子结构相关的趋势.
科学领域:
- 物理化学 物理化学
- 频谱学是一种光谱学.
- 计算化学的计算化学
背景情况:
- 金属离子在有机金属化学中至关重要.
- 了解它们的解离途径是预测反应性的关键.
- 之前的研究缺乏详细的能量和机制见解.
研究的目的:
- 研究金属离子 (Cp(2) M(+),M = Cr,Co,Ni) 的解离机制,能量和动力学.
- 确定0K出现能量和M-Cp键解离能量.
- 将键能与金属离子的电子结构相关联.
主要方法:
- 值光电子光离子巧合光谱 (TPEPICO) 用于能量选择的离子.
- 刚性激活复合体 (RAC) 米-拉姆斯珀格-卡塞尔-马库斯 (RRKM) 理论和简化的统计增离子通道模型 (SSACM) 用于建模.
- 密度函数理论 (DFT) 计算 (B3LYP/6-311G(d,p)) 用于结构和参数的确定.
主要成果:
- 通过失去中性环二烯连接体观察到初级碎片化.
- 确定了微小的碎片化通道 (CH,C(2) H(2) 损失) 和甲 (H原子损失) 和甲 (异构化,H(2) 损失的特定途径.
- 确定了0K的外观能量 (Cr: 10.57 ± 0.14 eV,Co: 11.01 ± 0.13 eV,Ni: 10.18 ± 0.13 eV) 和M-Cp键解离能量 (Cr: 5.04 ± 0.16 eV,Co: 5.77 ± 0.15 eV,Ni: 3.96 ± 0.15 eV). 通过测试,我们可以测量出0K的外观能量.
结论:
- 简化统计增离子通道模型 (SSACM) 为解离能学提供了可靠的结果.
- M-Cp键能量的趋势与金属离子的电子结构有关.
- 这项研究为了解金属离子化学和反应性提供了关键数据.
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