Zhang Yongliang, Wei Junnian, Zhu Miaomiao, Chi Yue, Zhang Wen-Xiong, Ye Shengfa, Xi Zhenfeng
Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University, Beijing, 100871, P. R. China.
Max-Planck Institute for Coal Research, 45470, Mülheim a. d. Ruhr, Germany.
Angew Chem Int Ed Engl. 2019 Jul 8;58(28):9625-9631. doi: 10.1002/anie.201904681. Epub 2019 Jun 11.
Herein, we present the realization of a class of unprecedented aromatic structures 2: metalla-aromatics with two independent and perpendicular aromatic rings spiro-fused by a transition-metal spiro atom, of which their corresponding organic analogues are impossible. Tetralithio spiro manganacycles 2 are readily synthesized from 1,4-dilithio-1,3-butadienes 1 and MnCl in the presence of lithium. The aromaticity of 2 is supported by experimental measurements (X-ray structural analysis, NMR) and theoretical analyses (NICS, ACID, MOs). The spiro atom Mn in 2 uses its 3d and 3d orbitals to form the two perpendicular manganacycles, which are two independent 6π aromatic systems. Theoretical analyses reveal that the Li cations play an indispensable role in governing their geometric and electronic structures and hence their aromaticity. Therefore, this work contributes not only to enrich the concept of aromaticity, but also to deepen the understanding of the fundamental chemical bonding.
在此，我们展示了一类前所未有的芳香结构2：金属芳香化合物，其具有两个由过渡金属螺原子螺稠合的独立且垂直的芳香环，而其相应的有机类似物是不可能存在的。四硫代螺锰环2可在锂存在下由1,4 - 二锂 - 1,3 - 丁二烯1和MnCl轻松合成。2的芳香性得到了实验测量（X射线结构分析、核磁共振）和理论分析（核独立化学位移、分子中的原子量子理论、分子轨道）的支持。2中的螺原子Mn利用其3d和3d轨道形成两个垂直的锰环，它们是两个独立的6π芳香体系。理论分析表明，Li阳离子在控制其几何和电子结构以及因此其芳香性方面起着不可或缺的作用。因此，这项工作不仅有助于丰富芳香性的概念，还有助于加深对基本化学键的理解。
