第一排过渡金属复合物的不寻常的电子结构,其中包括具有氧化还原活性的二氧化甲配体
Evan R King1, Theodore A Betley
1Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, 306E Mallinckrodt, Cambridge, Massachusetts 02138, USA.
Journal of the American Chemical Society
|October 8, 2009
概括
新的过渡金属复合物与二氧化甲连接体显示出一种独特的协调模式. 它们的电子结构和氧化途径是以连接体为基础的,独立于金属离子,几何或自旋状态.
科学领域:
- 协调化学 协调化学
- 有机金属化学 有机金属化学
- 材料科学 材料科学 材料科学
背景情况:
- 二氧化甲连接物是协调化学中的多功能构建块.
- 来自替代物的固体阻碍可以影响金属协调模式.
- 了解金属复合物的电子结构对于催化和材料应用至关重要.
研究的目的:
- 为了合成和描述1,9-dimesityl-5,5-dimethyldipyrromethane (dpm) 的过渡金属复合物.
- 研究这些复合体的协调行为和电子特性.
- 探索dpm连接体框架内的电化学氧化路径.
主要方法:
- 用dpm联体合成过渡金属复合物 (Mn到Zn) 的合成.
- 用X射线衍射进行结构确定.
- 用SQUID和EPR光谱进行磁性表征.
- 微分脉冲电压测量用于电化学分析.
- 密度函数理论 (DFT) 用于电子结构计算.
主要成果:
- 由于固态阻碍,dpm配体采用eta(1),eta(1) 协调模式.
- (II),铁 (II) 和 (II) 复合体是高旋转和伪四面体的.
- (II) 复合体是低旋转和正方形平面的.
- 在整个系列中观察到一种常见的基于联体的两电子氧化途径.
- DFT的计算证实,最高的分子轨道是基于联体的.
结论:
- 这些dpm金属复合物的电子结构和氧化行为主要是由连接体决定的,而不是金属中心.
- dpm框架为氧化还原活性金属复合物提供了一个稳定的平台.
- 在这个系列中没有观察到分子内氧化还原活性或自旋状态的复合体.
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