Probing the Most Aromatic and Antiaromatic Pyrrolium Rings by Maximizing Hyperconjugation and Push-Pull Effect
Probing the Most Aromatic and Antiaromatic Pyrrolium Rings by Maximizing Hyperconjugation and Push-Pull Effect
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DOI：
10.1002/asia.201800179
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发表时间：
2018-06-04
影响因子：
4.1
通讯作者：
Zhu, Jun
中科院分区：
文献类型：
--
作者：
Sun, Tingting;Xie, Qiong;Zhu, Jun
超共轭是有机化学中的一种弱相互作用，它对芳香性有很强的影响，因此Mulliken在1939年首次提出了超共轭芳香性的概念。然而，大多数研究仅限于主族化学。在这里，我们报告了最芳香和反芳香的吡咯环，通过最大限度地提高过渡金属片段和推拉效应引起的超共轭。我们的计算表明，过渡金属取代基的超共轭芳香性优于主族取代基的起源可以归因于其较高的最高占据分子轨道（HOMO）。在第11族过渡金属中，银取代基导致最佳性能。所有这些发现都突出了过渡金属（银）的魔力，并可能特别有助于基于非芳香族母体物种设计其他芳香族和反芳香族对应物。
Hyperconjugation, a weak interaction in organic chemistry, can have a strong effect on aromaticity, leading to the concept of hyperconjugative aromaticity, which was first proposed by Mulliken in 1939. However, most studies are limited to main group chemistry. Here we report the most aromatic and antiaromatic pyrrolium ring by maximizing the hyperconjugation caused by transition metal fragments and the push-pull effect. Our calculations reveal that the origin of the outperformance of transition metal substituents over main group ones on hyperconjugative aromaticity could be attributed to their higher highest occupied molecular orbitals (HOMOs). Among the group 11 transition metals, a silver substituent results in the best performance. All these findings highlight the magic of the transition metal (silver) and could be particularly helpful for the design of other aromatic and antiaromatic counterparts based on a nonaromatic parent species.