How does aromaticity rule the thermodynamic stability of hydroporphyrins?
How does aromaticity rule the thermodynamic stability of hydroporphyrins?
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DOI：
10.1002/chem.201002599
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发表时间：
2011-03
期刊：
影响因子：
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通讯作者：
Nicolás Otero;S. Fias;S. Radenković;P. Bultinck;A. M. Graña;M. Mandado
中科院分区：
文献类型：
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作者：
Nicolás Otero;S. Fias;S. Radenković;P. Bultinck;A. M. Graña;M. Mandado
包括能量、磁性和电子密度标准在内的几种芳香性标准被用来说明芳香稳定性如何解释氢卟啉的稳定性顺序，从卟啉到八氢卟啉，以及它们的首选氢化路径。所采用的方法包括拓扑共振能量及其电路能量效应、键共振能量、多中心离域指数、环电流图、磁化率和与核无关的化学位移。为了比较不同方法所获得的信息，我们采用最近提出的方法将结果放在同一个尺度上。研究发现，所有这些方法提供的信息基本相同，得出的结论也相似。用密度泛函理论计算了卟啉与八氢卟啉在不同加氢路径上的氢化能。通过上述方法表明，不同氢卟啉异构体的相对稳定性和八氢卟啉在合成和自然界中所观察到的不可接近性可以从芳香性方面得到很好的解释。
Several measures of aromaticity including energetic, magnetic, and electron density criteria are employed to show how aromatic stabilization can explain the stability sequence of hydroporphyrins, ranging from porphin to octahydroporphin, and their preferred hydrogenation paths. The methods employed involve topological resonance energies and their circuit energy effects, bond resonance energies, multicenter delocalization indices, ring current maps, magnetic susceptibilities, and nuclear-independent chemical shifts. To compare the information obtained by the different methods, the results have been put in the same scale by using recently proposed approaches. It is found that all of them provide essentially the same information and lead to similar conclusions. Also, hydrogenation energies along different hydrogenation paths connecting porphin with octahydroporphin have been calculated with density functional theory. It is shown by using the methods mentioned above that the relative stability of different hydroporphyrin isomers and the observed inaccessibility of octahydroporphin both synthetically and in nature can be perfectly rationalized in terms of aromaticity.