扭曲的芳香性：莫比乌斯[4n]轮烯。

Aromaticity with a twist: Möbius [4n]annulenes.

作者信息

Castro Claire, Isborn Christine M, Karney William L, Mauksch Michael, von Ragué Schleyer Paul

机构信息

Department of Chemistry, University of San Francisco, 2130 Fulton Street, San Francisco, CA 94117, USA.

出版信息

Org Lett. 2002 Oct 3;4(20):3431-4. doi: 10.1021/ol026610g.

DOI:10.1021/ol026610g

PMID:12323036

Abstract

Aromatic Möbius [4n]annulenes with 4n pi electrons, originally conceived by Heilbronner, are characterized computationally. These (CH)(12), (CH)(16), and (CH)(20) minima have nearly equal C-C bond lengths, small twist angles around the rings, and magnetic properties (NICS, nucleus-independent chemical shifts--see above at various positions in [16]annulene--and magnetic susceptibility exaltations) indicating significantly diatropic ring currents. The Möbius forms are not the most stable isomers but may contribute significantly to the chemistry of these annulenes. [structure: see text]

摘要

最初由海布伦纳提出的具有4n个π电子的芳香性莫比乌斯[4n]轮烯，通过计算进行了表征。这些(CH)₁₂、(CH)₁₆和(CH)₂₀的极小值具有几乎相等的C-C键长、围绕环的小扭转角以及磁性性质（NICS，即核独立化学位移——见上文[16]轮烯中不同位置的情况——以及磁化率增强），表明存在显著的抗磁环电流。莫比乌斯形式并非最稳定的异构体，但可能对这些轮烯的化学性质有显著贡献。[结构：见正文]