可相互转换的氧TAML中间体的识别,表征和电子结构
Deesha D Malik1, Wooyeol Ryu2, Yujeong Kim3
1Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea.
Journal of the American Chemical Society
|May 8, 2024
概括
一个蓝色的-TAML复合物 (1) 在冷却后可逆地转化为绿色的物种 (2). 这种相互转换涉及陶托美化,影响氧和原子转移反应中的电子结构和反应性.
科学领域:
- 协调化学
- 生物有机化学
- 光谱学和理论化学
背景情况:
- 在生物模拟氧化催化过程中,四胺宏循环配体 (TAML) 是至关重要的.
- 了解-TAML复合物的电子结构是阐明它们的催化机制的关键.
- 协调复合体中的温度依赖转换可以显示动态电子变化.
研究的目的:
- 合成和描述新的蓝色和绿色TAML物种 (1和2).
- 使用先进的光谱和理论方法阐明1和2种类的电子结构.
- 研究1号和2号物种之间的温度依赖性相互转换及其对反应性的影响.
主要方法:
- 在基和易斯/布伦斯特德酸的存在下合成-TAML复合物.
- 使用X波段电子磁共振 (EPR),电子核双共振 (ENDOR),X射线吸收光谱/扩展的X射线吸收细结构 (XAS/EXAFS) 和磁圆二极化 (MCD) 的表征.
- 在氧原子转移 (OAT) 和原子转移 (HAT) 反应中使用ab initio理论研究和反应性研究进行计算分析.
主要成果:
- 一种蓝色物种 (1) 被确定为具有抗铁磁合的S=1/2 [(Sol) ((TAML•+) CoIII---OH ((LA)) 复合体.
- 一种在冷却后可逆形成的绿色物种 (2) 呈现出多配置电子结构,其中包括Co ((IV) 和质子化的TAML连接物.
- 1和2之间的相互转换涉及易斯/布伦斯特德酸相关的分体化,改变了氧物种的特征.
结论:
- 这项研究揭示了-TAML复合体中一种新型的温度依赖性复合,影响了它们的电子配置.
- 1和2种不同的电子结构导致OAT和HAT反应的反应性不同.
- 这项工作为基于的氧化催化剂的结构反应关系提供了基本的见解.
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