Copper Corroles Are Inherently Saddled
Copper Corroles Are Inherently Saddled
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DOI：
10.1021/ic900744v
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发表时间：
2009-08-17
影响因子：
4.6
通讯作者：
Ghosh, Abhik
中科院分区：
文献类型：
--
作者：
Alemayehu, Abraham B.;Gonzalez, Emmanuel;Ghosh, Abhik
两种空间位阻不受阻碍的铜meso-triarylcorroles，Cu[5，15-P-2-10-（4-MeOP）C]和Cu[5，15-（4-CF 3 P）（2）-10-（4-MeOP）C]（P =苯基和C = corrole）的X射线晶体学分析揭示了基本上鞍形的corrole环。这些结果是在显着的对比高度空间位阻的钴（III）和铱（III）corroles，表现出平面corrole大环。这个难题的解决方案是，铜咯是固有的鞍形，作为一个特定的铜（d）-咔咯（pi）轨道相互作用的结果。这种轨道相互作用产生了一个非无辜的咔咯配体，因此整个电子结构可以描述为Cu-II-咔咯（中心点2-）。虽然许多特定的金属（d）-大环（pi）轨道相互作用是已知的非平面金属卟啉，这项工作提供了一个罕见的例子，这样的轨道相互作用提供了一个显着的非平面扭曲的实际驱动力。我们对铜腐蚀物的发现，沿着其他人对钴和铱腐蚀物的发现，构成了金属腐蚀物结构化学中一个有趣的、有点违反直觉的章节。
X-ray crystallographic analyses of two sterically unhindered copper meso-triarylcorroles, Cu[5,15-P-2-10-(4-MeOP)C] and Cu[5,15-(4-CF3P)(2)-10-(4-MeOP)C] (P = phenyl and C = corrole), revealed substantially saddled corrole rings. These results are in marked contrast to those on highly sterically hindered cobalt(III) and iridium(III) corroles, which exhibit planar corrole macrocycles. The solution to this conundrum is that copper corroles are inherently saddled, as a result of a specific copper(d)-corrole(pi) orbital interaction. This orbital interaction results in a noninnocent corrole ligand, and the overall electronic structure may thus be described as Cu-II-corrole(center dot 2-). While many specific metal(d)-macrocycle(pi) orbital interactions are known for nonplanar metalloporphyrins, this work provides a rare example of such an orbital interaction providing the actual driving force for a significant nonplanar distortion. Our findings on copper corroles, along with those of others on cobalt and iridium corroles, thus constitute an intriguing and somewhat counterintuitive chapter in the structural chemistry of metallocorroles.