School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang, 212100, People's Republic of China.
Beijing Kein Research Center for Natural Sciences, Beijing, 100022, People's Republic of China.
Chemistry. 2023 Jun 2;29(31):e202300348. doi: 10.1002/chem.202300348. Epub 2023 Apr 20.
Herein, the electronic structure and bonding character of the stable cyclo[18]carbon (C ) precursor, C Br , are thoroughly characterized by molecular orbital (MO), density of states (DOS), bond order (BO), and interaction region indicator (IRI) analyses. The delocalization characters of out-of-plane and in-plane π-electrons (labeled as π - and π -electrons, respectively) in bonding regions were examined using localized orbital locator (LOL) and electron localization function (ELF). The aromaticity was investigated, studying the molecular magnetic response to external magnetic field by computing the magnetically induced current density (J ), iso-chemical shielding surface (ICSS), anisotropy of the induced current density (AICD), and the induced magnetic field (B ). All these analyses indicate that C Br is a globally aromatic species with lower aromaticity than C , and the blocking of in-plane π-conjugation (labeled as π -conjugation) by the presence of -Br substituents in it is the underlying cause for the weakening of molecular aromaticity.
本文通过分子轨道（MO）、态密度（DOS）、键序（BO）和相互作用区域指标（IRI）分析，深入研究了稳定的[18]轮烯（C ）前体 C Br 的电子结构和键合特性。使用局域轨道定位器（LOL）和电子定域函数（ELF）研究了键合区域中面外和面内π-电子（分别标记为π -和π -电子）的离域特性。通过计算磁诱导电流密度（J）、等化学屏蔽表面（ICSS）、诱导电流密度各向异性（AICD）和诱导磁场（B），研究了分子对外磁场的磁响应，从而研究了其芳香性。所有这些分析表明，C Br 是一种全局芳香性物质，其芳香性低于 C ，并且其分子芳香性减弱的根本原因是 -Br 取代基对其面内π-共轭（标记为π -共轭）的阻断。
