通过单核铜的原子抽象机制:原子转移或协同的质子合电子转移?
Mukunda Mandal1, Courtney E Elwell1, Caitlin J Bouchey1,2
1Department of Chemistry, Minnesota Supercomputing Institute, Chemical Theory Center, and Center for Metals in Biocatalysis , University of Minnesota , 207 Pleasant Street SE , Minneapolis , Minnesota 55455 , United States.
Journal of the American Chemical Society
|October 17, 2019
概括
用二胺联体的铜 (III) 复合物通过原子转移 (HAT) 和协同质子合电子转移 (cPCET) 机制激活X-H键. 反应性根据铜的功能和基质而异,复合物1是最有反应性的.
科学领域:
- 协调化学
- 有机金属化学
- 催化剂
背景情况:
- 众所周知,铜-氧复合物以仿生方式激活X-H键 (X = C,O).
- 连接体框架N,N'-bis ((2,6-二异甲) -2,6-氨基胺 (L2−) 在稳定高价值铜物种中起着至关重要的作用.
- 了解X-H键激活的机制是开发新的催化过程的关键.
研究的目的:
- 合成和表征一种具有甲基基的新型铜 (III) 复合物,LCu (III) -O2CAr1 (3).
- 研究和比较复合体1,2和3的X-H键激活活性.
- 阐明在观察到的X-H键激活中涉及的机械途径 (原子转移与协同的质子合电子转移).
主要方法:
- 铜 (III) 复合物的合成和表征.
- 用于确定各种含有O-H和C-H的基质的反应速率的动态研究.
- 应用理论工具来区分原子转移 (HAT) 和协同质子合电子转移 (cPCET) 机制.
主要成果:
- 复合物1在X-H键激活中表现出最高的反应性,其次是复合物3,而复合物2则没有反应性.
- 动力学测量显示了具有明显速度差异的二次反应动力学.
- 鉴定出HAT和cPCET是X- H键激活的活性途径,因基质和铜复合体结构而有所不同.
结论:
- 在X-H键激活过程中,正式铜 (III) 复合物的反应性受其氧化能力和特定功能化机制的影响.
- 这项研究强调了二胺联体在支持能够激活多种X-H键的反应性铜 (III) 物种中的多功能性.
- 这项工作为铜介导键激活的机械细微差别提供了洞察力,这与仿生和催化应用有关.
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