Adaptive aromaticity in So and T1 states of pentalene incorporating 16 valence electron osmium
Adaptive aromaticity in So and T1 states of pentalene incorporating 16 valence electron osmium
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DOI：
10.1038/s42004-018-0018-y
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发表时间：
2018-04-05
影响因子：
5.9
通讯作者：
Zhu, Jun
中科院分区：
文献类型：
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作者：
Chen, Dandan;Shen, Ting;Zhu, Jun
芳香性是一个基本的化学概念，其多样性不断增加。根据Huckel和Baird规则，具有4 n +2 π电子的环状共轭物种在单重电子基态（S-o）是芳香的，在最低三重态（T-1）是反芳香的，反之亦然。因此，在这两种状态下都具有芳香性的物种还没有报道。在这里，我们进行密度泛函理论计算最近合成的有机金属，即osmapentalyne和osmapentalenes，并证明了第一个例子（16电子osmapentalene）的芳香性在S-O和T-1状态，我们术语自适应芳香性。进一步的电子结构分析表明，T-1态形成的激发模式在自适应芳香性的实现中起着至关重要的作用。我们的研究结果突出了过渡金属在非正统激发行为中的作用，并可能有助于设计用于光化学和分子磁性应用的自适应芳烃。
Aromaticity is a fundamental chemical concept of ever-increasing diversity. According to Huckel's and Baird's rules, cyclic conjugated species with 4n+2 pi-electrons are aromatic in the singlet electronic ground state (S-o) and antiaromatic in the lowest triplet state (T-1), and vice-versa. Thus, species with aromaticity in both states have not yet been reported. Here we carry out density functional theory calculations on recently synthesized organometallics, namely osmapentalyne and osmapentalenes, and demonstrate the first example (16-electron osmapentalene) of aromaticity in both S-o and T-1 states, which we term adaptive aromaticity. Further electronic structure analysis reveals that the excitation pattern for the formation of the T-1 state plays a crucial role in the achievement of adaptive aromaticity. Our findings highlight the role of a transition metal in unorthodox excitation behavior, and may aid the design of adaptive aromatics for photochemical and molecular magnetism applications.