调节电子结构以控制化激活
1Department of Chemistry, Simon Fraser University , 8888 University Drive, Burnaby, BC, Canada V5A 1S4.
Journal of the American Chemical Society
|December 10, 2016
概括
在 (V) 盐复合物中控制化物激活. 吸收电子的组加快了的合,而捐赠电子的组则稳定了该复合体.
科学领域:
- 协调化学
- 有机金属化学
- 材料科学
背景情况:
- 化 (V) 盐复合物是激活化学中的关键中间体.
- 联体的电子性质对金属复合物的反应性和稳定性有显著的影响.
- 了解结构与活动的关系对于设计高效的催化剂至关重要.
研究的目的:
- 研究对酸复合物的电子性质和反应性的对环置换剂的影响.
- 阐明化物激活和二合的机制.
- 与物种的稳定性和电子结构相关联.
主要方法:
- 一系列化 (V) 复合物的合成和表征,具有不同的环替代剂 (CF3,tBu,NMe2).
- 电化学氧化研究以产生更高的氧化状态.
- 用光谱技术 (例如,UV-Vis,EPR) 来分析产生的物种的电子结构.
- 用于评估复杂稳定性的可变温度研究.
主要成果:
- 用取电子的替代物 (CF3,tBu) 氧化化 (V) 复合物产生了MnVI) 种,表明化的激活.
- 观察到二同并发现被电子撤回的CF3组加速.
- 具有电子捐赠NMe2替代物的复合物形成稳定的连接基物种,抑制N-N合并表现出在195K和298K的稳定性.
结论:
- 远程连接器电子是这些系统中化物激活的主要决定因素.
- 提取电子的替代剂促进化物激活和二合,而电子捐赠组则导致稳定的连接基物种.
- 这项研究提供了通过连接体设计控制化化学反应性和稳定性的见解.
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