高等学校化学学报 ›› 2006, Vol. 27 ›› Issue (3): 510.

• 研究论文 • 上一篇    下一篇

联苯桥联的PPV齐聚物基态构型、电子能级和吸收光谱的理论研究

许海1,2,杨兵1,2,何凤1,解增旗1,田雷蕾1,刘晓冬2,于景生1,马於光1   

  1. 1. 吉林大学超分子结构与材料教育部重点实验室, 2. 吉林大学化学学院, 长春 130012
  • 收稿日期:2005-04-08 出版日期:2006-03-10 发布日期:2006-03-10
  • 通讯作者: 马於光(1963年出生),男,教授,博士, 博士生导师,主要从事聚合物光电功能材料研究. E-mail: ygma@jlu.edu.cn
  • 基金资助:

    国家“九七三”计划(批准号: 2002CB613403)和国家自然科学基金(批准号: 50303007, 50473001)资助.

Theoretical Studies on Ground State Structure, Electronic Energy Level and Absorption Spectra of PPV Oligomers with Biphenyl Bridge

XU Hai1,2, YANG Bing1,2, HE Feng1, XIE Zeng-Qi1, TIAN Lei-Lei1, LIU Xiao-Dong2, YU Jing-Sheng1, MA Yu-Guang1*   

  1. 1. Key Lab for Supramolecular Structure and Materials of Ministry of Education,
       2. College of Chemistry, Jilin University, Changchun 130012, China
  • Received:2005-04-08 Online:2006-03-10 Published:2006-03-10

摘要:

用密度泛函方法对联苯桥联的PPV齐聚物(TSB)的反式结构进行全优化,得到基态分子的最优几何构型和电子能级,并用ZINDO和TD-DFT方法分别计算其吸收光谱,分析了不同类型的端位取代基团对前线分子轨道能量和能隙的影响. 结果表明,联苯桥联后的PPV齐聚物在结构上形成了链间交叉链内扭曲的构象,这种交叉扭曲的构象降低了分子的对称性,减弱了共轭分子在固体中的π-π堆积作用,这可能是减少荧光猝灭效应,提高固体发光器件效率的重要原因.

关键词: PPV齐聚物; 密度泛函; 基态构型; 电子能级; 吸收光谱

Abstract:

We  fully optimized the trans-structures of PPV oligomer with biphenyl bridge using DFT/B3LYP method with Gaussian 98 software and gained the most rational geometry structure of ground state and electronic energy level. Then the absorption spectra data are calculated at ZINDO and TD-DFT levels of theory. We also analyzed the factors that different substituent groups connecting to the end of molecules impacted the frontier molecular orbitals and the energy gap. The results indicate that the PPV oligomer with biphenyl bridge is a cross form between two chains and tortuose derivative in the same chain. It reduces molecular symmetry and weakens π-π stacking effect among conjugated molecules in solid. This is perhaps the important factor that light-emitting diodes can increase fluorescence quantum efficiency.

Key words: PPV oligomer; DFT; Structure of ground state; Electronic energy level; Absorption spectrum

中图分类号: 

TrendMD: