具有超低LUMO/HOMO能级的稠环芳烃分子  

Polycyclic Aromatic Hydrocarbon Molecule with Ultra-low LUMO/HOMO Energy Levels

作　　者：刘蕊[1] 孟彬[2] 胡俊丽[1] 刘俊[2] Liu Rui;Meng Bin;Hu Junli;Liu Jun(Key Laboratory of UV-Emitting Materials and Technology,Ministry of Education,Northeast Normal University,Changchun 130024,China;State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China)

机构地区：[1]东北师范大学、紫外光发射材料与技术教育部重点实验室,长春130024 [2]中国科学院长春应用化学研究所、高分子物理与化学国家重点实验室,长春130022

出　　处：《化学学报》2023年第10期1295-1300,共6页Acta Chimica Sinica

基　　金：国家自然科学基金(Nos.22075273,22275029);吉林省科技发展计划项目(No.20220204097YY)资助.

摘　　要：低LUMO/HOMO(最低未占分子轨道/最高占据分子轨道)能级的有机小分子的种类和数量都很少,其设计与合成具有重要的科学价值和应用价值.传统的设计超低LUMO/HOMO能级有机小分子的策略是在分子中引入多个氰基.本工作设计并合成了含有四个硼氮配位键和两个酰亚胺基团的稠环芳烃分子,不含有氰基.该分子的LUMO能级低至-4.77 eV,HOMO能级低至-6.39 eV,是已报道的硼氮配位键稠环小分子的最低值,和已报道的氰基类有机小分子具有可比性.该分子呈现曲面构型,共轭骨架呈23.6°的二面角,LUMO和HOMO都均匀地离域在线型并苯骨架上.它在溶液态和薄膜态都展现出明显的近红外吸收,薄膜最大吸收波长为768 nm.该分子可以用作p-型掺杂剂,提高p-型高分子的电导率.本工作开拓出不采用氰基实现有机小分子超低LUMO能级的新途径.Organic small molecules of low LUMO/HOMO(lowest unoccupied molecular orbital/highest occupied molecular orbital)energy levels are in shortage in terms of both variety and quantity.Their design and synthesis have important scientific and application value.The traditional strategy for designing organic small molecules of ultra-low LUMO/HOMO energy levels is to introduce multiple cyano groups into the molecules.In this work,a polycyclic aromatic hydrocarbon molecule containing four boron and nitrogen coordination bonds and two imide groups is designed and synthesized,without involving any cyano groups.The cyclic voltammetry examination with 0.1 mol·L^(−1) tetrabutylammonium hexafluorophosphate solution in dichloromethane as the electrolyte solution and ferrocene as the internal standard indicates that the molecule has a low LUMO and HOMO energy level of-4.77 eV and-6.39 eV,respectively.These values are the lowest for the reported fused-ring small molecules with boron and nitrogen coordination bonds and comparable to those of the reported organic small molecules with cyano groups.The density functional theory calculation results at the B3LYP/6-31G(d,p)theoretical level show that the molecule has a curved configuration and its conjugate skeleton has a dihedral angle of 23.6°.Both LUMO and HOMO are uniformly delocalized on the linear benzoid skeleton.It shows obvious near-infrared absorption in both solution and thin film state,with maximum absorption at 768 nm in film.The molecule can be used as a p-type dopant.After its blend doping,the electrical conductivity of the film of a typical p-type polymer P3HT is improved by 3 orders of magnitude.The doping behavior is also confirmed by UV-Vis absorption spectroscopy and electron paramagnetic resonance spectroscopy.This work develops a new strategy to achieve ultra-low LUMO energy level for organic small molecules without using cyano groups.

关 键 词：能级 硼氮配位键 酰亚胺 p-掺杂 稠环分子 

分 类 号：O641.4[理学—物理化学] O625.1[理学—化学]