凯库勒烯芳香性及光诱导电荷转移物理机制研究  

Aromaticity of Kekulene and Physical Mechanism of Photoinduced Charge Transfer

作　　者：冯伟键 邹怡 王金刚 FENG Weijian;ZOU Yi;WANG Jingang(College of Science,Liaoning Petrochemical University,Fushun Liaoning 113001,China)

机构地区：[1]辽宁石油化工大学理学院,辽宁抚顺113001

出　　处：《石油化工高等学校学报》2024年第2期24-30,共7页Journal of Petrochemical Universities

基　　金：辽宁省自然科学基金面上项目(2022-MS-363);辽宁省教育厅基本科研面上项目(LJKMZ20220735)。

摘　　要：芳香性是芳香族化合物的重要化学性质之一,明确环状共轭体系的芳香性对了解体系的化学反应性能和稳定性至关重要。通过量子化学计算和波函数分析对凯库勒烯(Kekulene)的芳香性、单光子吸收(OPA)和双光子吸收(TPA)光谱及电子转移特性进行了详细的研究;通过多中心键级和AV1245指数对分子中不同苯环的芳香性进行了定量分析;通过电子定域化函数(ELF)、定域化轨道定位函数(LOL)、磁感生电流和等化学屏蔽表面(ICSS)等多种方法,对Kekulene的芳香性进行了研究;通过电荷差分密度(CDD)对OPA和TPA跃迁过程的电子转移进行了可视化分析。结果表明,1、2环的芳香性明显强于3、4环;ELF和LOL的π电子可以在1环两侧高度离域并形成回路;OPA光谱具有较高跃迁偶极矩的激发态,更易成为TPA过程中的中间态。研究结果可为不同体系的芳香性提供有效的理论方法和应用途径。Aromaticity is one of the important chemical properties of aromatic compounds.Clarifying the aromaticity of a clearly ring⁃conjugated system is crucial for understanding the chemical reactivity and stability of the system.A detailed study of the aromaticity,one⁃photon absorption(OPA),two⁃photon absorption(TPA)spectra,and electron transfer properties of Kekulene was carried out through quantum chemical calculations and wave function analysis.The aromaticity of different benzene rings in the molecule was quantitatively analyzed through multicenter bond indices and AV1245 indices.The aromaticity of Kekulene was studied through various methods such as electron localization function(ELF),localized orbital locator(LOL),magnetic susceptibility current,and isotropic chemical shielding surface(ICSS).The electron transfer processes of OPA and TPA transitions were visualized through charge difference density(CDD)analysis.The results showed that the aromaticity of rings 1 and 2 was significantly stronger than that of rings 3 and 4.Theπelectrons of ELF and LOL can be highly delocalized on both sides of the first ring and form a loop.The OPA spectrum has excited states with higher transition dipole moments,which are more likely to become intermediate states in the TPA process.The research results can provide effective theoretical methods and application approaches for the aromaticity of different systems.

关 键 词：芳香性 电子离域 磁感应电流 ICSS 电子跃迁 

分 类 号：TQ012[化学工程]