物理化学学报 >> 2009, Vol. 25 >> Issue (02): 347-352.doi: 10.3866/PKU.WHXB20090226

研究论文 上一篇    下一篇

4-(1,2-二苯基)乙烯基-4’-(N,N-二苯基-4-乙烯基苯胺基)联苯及其二氟取代衍生物的电子结构与光谱性质

崔明侠; 董士红; 王文亮; 尹世伟; 吕剑   

  1. 陕西省大分子科学重点实验室, 陕西师范大学化学与材料科学学院, 西安 710062; 西安近代化学研究所, 西安 710065
  • 收稿日期:2008-09-08 修回日期:2008-10-31 发布日期:2009-01-16
  • 通讯作者: 王文亮 E-mail:wlwang@snnu.edu.cn

Electronic Structures and Spectroscopic Properties of 4-[(1,2-Diphenyl)-4’-(N,N-diphenyl-4-vinylbenzenamine)] Biphenyl and Its Difluorinated Derivatives

CUI Ming-Xia; DONG Shi-Hong; WANG Wen-Liang; YIN Shi-Wei; LV Jian   

  1. Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, Xi’an 710062, P. R. China; Xi’an Institute of Modern Chemistry, Xi’an 710065, P. R. China
  • Received:2008-09-08 Revised:2008-10-31 Published:2009-01-16
  • Contact: WANG Wen-Liang E-mail:wlwang@snnu.edu.cn

摘要: 分别采用B3LYP/6-31G(d)和CIS/6-31G(d)方法对4-(1,2-二苯基)乙烯基-4’-(N,N-二苯基-4-乙烯基苯胺基)联苯(A)及其二氟取代衍生物(B-F)的基态(S0)和单重激发态(S1)的几何构型进行了全优化, 计算获得了电离势IP、电子亲和势EA等相关数据, 并采用含时密度泛函(TD-DFT)方法计算了上述化合物的电子吸收和荧光发射光谱. 研究结果表明, 化合物A及二氟取代衍生物B-F在469-474 nm蓝光区域主发射峰的强度远远大于372-387 nm范围的次发射峰, 说明此类化合物具有纯度较高的发射光谱; 主链苯环上的二氟取代(B, C和D)使最低空轨道(LUMO)能级明显降低, 有利于提高电子注入; 芳胺基苯环上的二氟取代(D和E)使分子最高占据轨道(HOMO)能级明显降低, 电离势增加, 能隙变大, 有利于抑制空穴越过发光层向电子传输层输运, 减少界面处激基复合物的形成, 同时起到光谱蓝移的效果; 既是主链苯环上也是芳胺基苯环上的二氟取代衍生物D更有利于平衡电子-空穴的注入, 应该具有更加优良的发光性质.

关键词: 联苯乙烯基衍生物, 密度泛函理论, 空穴阻挡, 光谱性质, 电子结构

Abstract: Electronic structures and spectroscopic properties of 4-[(1,2-diphenyl)-4’-(N,N-diphenyl-4-vinylbenzenamine)] biphenyl and its difluorinated derivatives were studied. B3LYP/6-31G(d) and CIS/6-31G(d)methods were used to optimize the ground and excited state geometries, respectively, and the data for ionization potentials (IPs) and electron affinities (EAs) were also obtained. Absorption and emission spectra were calculated using time-dependent density functional theory (TD-DFT) based on ground and excited state geometries.We found that the main emission peak intensity at 469-474 nmis far more larger than the second emission peak at 372-387 nm, which indicates that this type of compound has its own highly pure emission wavelength. Difluoro-substituted derivatives on the benzene of the main chain (B, C and D) cause an energy lowering of the lowest unoccupied molecular orbital (LUMO) energy levels obviously, which facilitates the injection of electron carriers from the metal electrode. Difluoro-substituted derivatives on the benzene of benzenamine (D and E) cause an energy lowering of the highest occupied molecular orbitals (HOMO) obviously. The increasing of IP and energy gap, which is proper to hold hole transfer from the emission layer to the electron transport layer, reduces the formation of exciplexes at the interface and causes a blue-shift of spectra. The difluoro-substituted derivative of benzene on both the main chain and benzenamine (D) is better for a balance of electron and hole injection which should result in even better emission properties.

Key words: Distyrylarylene derivative, Density functional theory, Hole blocking, Spectroscopic property, Electronic structure

MSC2000: 

  • O641