三种同分异构的双苯并吩噻嗪材料的合成、理论计算及光物理性质  

Isomeric Bisbenzophenothiazines:Synthesis,Theoretical Calculations,and Photophysical Properties

作　　者：王鹤然 陈凯[1] 伏硕 王晧暄 袁加轩 胡星奕 许文娟[1] 密保秀[1] Heran Wang;Kai Chen;Shuo Fu;Haoxuan Wang;Jiaxuan Yuan;Xingyi Hu;Wenjuan Xu;Baoxiu Mi(State Key Laboratory of Organic Electronics and Information Displays,Institute of Advanced Materials(IAM),Nanjing University of Posts&Telecommunications,Nanjing 210023,China.)

机构地区：[1]南京邮电大学信息材料与纳米技术研究院,有机电子与信息显示国家重点实验室,南京210023

出　　处：《物理化学学报》2024年第1期48-56,共9页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(21671109);江苏高校优势学科建设工程(PAPD,YX030003)资助项目。

摘　　要：吩噻嗪及其衍生物材料是一类重要的多环芳烃材料,在光电子领域有着广泛的应用。其中,基于苯并噻嗪材料的研究相对较少。在本文中,我们分别在吩噻嗪的1,2-、2,3-和3,4-位引入苯基,制备了三种同分异构的双苯并吩噻嗪化合物D-PTZa、D-PTZb和D-PTZc,研究了它们的构效关系,并与双吩噻嗪化合物(D-PTZ)进行了对比。研究发现,D-PTZb和D-PTZc的HOMO和LUMO分布与D-PTZ的类似;对于D-PTZa,其1,2-位引入的苯基与中间的苯环空间张力较大,造成空间结构极度扭曲,性质比较特殊。并苯的引入可以有效增加分子的共轭长度,使得最大吸收波长发生红移;在2,3-位引入苯基可以有效地稳定HOMO能级,使基于π→π*跃迁的能隙稍有增大,呈现蓝光发射,溶液的荧光量子产率为1.7%;而在3,4-位引入苯基使LUMO分布更加趋向于线型,从而使LUMO更加稳定,使基于π→π*跃迁的能隙降低,其最大发射峰位于520 nm处,呈现黄绿光发射,溶液荧光量子产率为13%。此外并入苯环之后,空间张力增大,化合物的分解温度降低。我们的分子设计和结构–性质关系的研究可以为设计新的吩噻嗪材料提供基础指导。Phenothiazines(PTZs),have received a lot of attention for many optoelectronic applications,such as hole-transporting layers,functioning as host materials for organic light-emitting diodes;dye sensitizers in dye-sensitized solar cells;and hole-transporting materials for perovskite solar cells.However,studies on benzophenothiazine materials are limited.In this study,we synthesize three isomeric bis-benzophenothiazine compounds(DPTZa,D-PTZb,and D-PTZc),all bearing an aromatic ring at the 1,2-,2,3-,and 3,4-positions,respectively.Next,we systematically investigate the relationship between their structures and properties and compare them with bis-phenothiazine compounds(D-PTZ).The highest occupied molecular orbital(HOMO)distributions for D-PTZb and D-PTZc are dispersed over benzophenothiazine moities,whereas the lowest unoccupied molecular orbitals(LUMOs)are localized at the middle phenyl-and naphthylgroups,which are similar frontier orbital distribuitions to the D-PTZ case.For D-PTZa,the steric hindrance between the phenyl groups at the 1,2-and middle positions increases,significantly distorting its spatial structure.Therefore,its HOMO and LUMO distributions differ from those of D-PTZb and D-PTZc.Notably,the HOMOs in D-PTZa are dispersed over the middle phenyl group and nitrogen atom,whereas the LUMOs are localized at the naphthyl group.The hole/electron excitation and frontier orbital analyses demonstrate that strong localπ→π*transition mixing with weak charge transfer transition is responsible for the luminescence of D-PTZb and D-PTZc.Interestingly,the ultraviolet–visible absorption spectra of all samples exhibit strongπ→π*transition absorption and weak n→π*transition absorption.Furthermore,the conjugated length of the molecule can be effectively increased with the introduction of an aromatic ring,resulting in a redshift in the maximum absorption wavelength.Compared to D-PTZ,D-PTZa emits yellow-green light with a photoluminescence quantum efficiency(PLQE)of 14%.In addition,the introduction of a phenyl g

关 键 词：苯并吩噻嗪 有机光电材料 密度泛函理论 空穴-电子分析 前线轨道分布 光物理性质 

分 类 号：O644[理学—物理化学]