共轭链对具有特殊电荷转移结构分子超极化率的影响  

Theoretical studies on the effect of conjugated chain on the hyperpolarizability of chromophores with unique charge transfer structure

作　　者：刘柳斜[1] 王薇[1] 李强根[1] 郑妍[1] 周芳[1] 李来才[1] 

机构地区：[1]四川师范大学化学与材料科学学院,成都610068

出　　处：《原子与分子物理学报》2017年第3期403-407,共5页Journal of Atomic and Molecular Physics

基　　金：四川省教育厅项目(16ZB0067)

摘　　要：近年来实验发现扭曲型分子内电荷转移(TICT)分子具有独特的分子内电荷转移机理和不同寻常的NLO响应系数.本文在MP2/6-311++G(d,p)水平上,结合有限场方法系统探讨了不同共轭链及共轭链长度对TICT分子一阶超极化率β的影响,并与传统D-π-A分子相比较.研究表明,共轭链对TICT分子与传统D-π-A分子β影响不同,且随着共轭链增长,TICT分子β提高更为显著.特别是共轭链为苯环的P4分子,当苯环重复单元数n=3时,其β远远大于其它具有不同共轭链的分子.In recent years, experiments have shown that twist intramolecular charge-transfer （TICT） chromophores may exhibit exceptionally large NLO response. In this work, we choose different conjugated chains and change their length to study the effect on the first hyperpolarizability β of TICT chromophores, and further compare the effect with traditional D-π-A molecules. With calculations at MP2/6-311＋＋G（d,p） level, different effects of conjugated chains on the β were noted between TICT chromophores and traditional D-π-A molecules, and β of TICT chromophores were enhanced larger than traditional D-π-A molecules with growth of conjugated chains. It is worth noting that the β of P4 is much larger than other TICT chromophores, when the number of repeat unit for benzene ring is 3.

关 键 词：共轭链 扭曲型分子内电荷转移分子 一阶超极化率 

分 类 号：O625.1[理学—有机化学]