使用悬浮氨基的移动质子:在催化剂中的质子流动性,用于氧化
Molly O'Hagan1, Wendy J Shaw, Simone Raugei
1Center for Molecular Electrocatalysis, Pacific Northwest National Laboratory, P.O. Box 999, K2-57, Richland, Washington 99352, USA.
Journal of the American Chemical Society
|May 21, 2011
概括
这项研究揭示了基氧化电催化剂中的快速分子内质子转移. 悬浮胺促进了质子的快速运动,这对催化效率和酶功能至关重要.
科学领域:
- 无机化学 无机化学 有机化学
- 催化剂是一种催化剂.
- 生物物理化学 生物物理化学
背景情况:
- 质子运输对许多化学和生物过程至关重要.
- 氧化电催化剂对于能源转换技术至关重要.
- 了解质子转移机制是设计高效催化剂和酶的关键.
研究的目的:
- 为了研究-悬浮氨基复合体中的分子内质子转移.
- 为了确定质子交换的动力学和能量学.
- 阐明悬浮胺在促进氧化催化过程中的质子转移中的作用.
主要方法:
- 可变温度1DNMR光谱学
- 2D EXSY 实验中的实验.
- 密度函数理论 (DFT) 的计算.
- 分子动力学 (MD) 模拟
主要成果:
- 观察到Ni和悬浮氨基之间的分子内质子交换在[Ni(P(Cy) ((2) N(Bn) ((2) H) ((2))) ((2+) 的特定异构体中.
- 质子交换速率常数在25°C时为10^4到10^5s^-1的范围,用于内置氨基.
- 确定了ΔG‡ = 11-12 kcal/mol的质子交换屏障,具有最小的溶剂依赖.
- 计算研究支持了实验结果,表明金属介导质子转移和椅子到船异构化是限制速度的步骤.
结论:
- 催化剂表现出高的分子内质子流动性,悬浮胺作为质子继电器.
- 这种移动性直接与加速氧化催化中的质子转移有关.
- 这些发现提供了对包括Ni-Fe酶在内的同质催化剂和酶中的质子运动的见解.
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