Radenković Slavko, Đorđević Slađana, Nikolendžić Marijana
University of Kragujevac, Faculty of Science, P.O. Box 60, Kragujevac, 34000, Serbia.
Chemistry. 2024 May 23;30(29):e202400361. doi: 10.1002/chem.202400361. Epub 2024 Apr 8.
In a series of earlier studies, the effect of benzo-annelation was found to be a useful tool for tuning the aromaticity in polycyclic conjugated compounds to desired level. In this work we studied the (anti)aromaticity of benzo-annelated derivatives of three conjugated hydrocarbons (anthracene, fluoranthene and biphenylene) in their lowest lying singlet (S) and triplet (T) states by means of the energy effect (ef), harmonic oscillator model of aromaticity (HOMA), multicentre delocalization indices (MCI), magnetically induced current densities (MICDs) and nucleus independent chemical shifts (NICS). We showed that benzo-annelation is a topology-based effect which can be used to modify the T state excitation energies (E(T)). A quantitative model was established being able to accurately predict the E(T) based only on the numbers of angularly, linearly and geminally annelated benzene rings. In addition, it was demonstrated that the E(T) can be directly related to the (anti)aromatic character of the central ring in the studied molecules in their S state.
在一系列早期研究中，发现苯并稠合效应是一种将多环共轭化合物的芳香性调节至所需水平的有用工具。在这项工作中，我们通过能量效应（ef）、芳香性的谐振子模型（HOMA）、多中心离域指数（MCI）、磁诱导电流密度（MICD）和核独立化学位移（NICS），研究了三种共轭烃（蒽、荧蒽和联苯撑）的苯并稠合衍生物在其最低单重态（S）和三重态（T）下的（反）芳香性。我们表明，苯并稠合是一种基于拓扑结构的效应，可用于改变三重态激发能（E(T)）。建立了一个定量模型，该模型仅基于角向、线性和偕位稠合苯环的数量就能准确预测E(T)。此外，结果表明，E(T)与所研究分子在单重态下中心环的（反）芳香特性直接相关。
