单体间距离对二聚体分子一阶超极化率的影响  

Theoretical Studies on the Effect of Distances between Chromophores on the Molecular First Hyperpolarizability of Dimer

作　　者：刘柳斜[1] 李权[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：《化学通报》2014年第8期790-794,共5页Chemistry

摘　　要：近年来实验发现,通过化学键调整分子间空间取向可以提高其非线性光学(NLO)响应系数。本文以对硝基苯酚分子为单体,利用化学键将两个单体连接得到一系列二聚体分子,用量子化学方法计算了它们的分子一阶超极化率(β)。研究表明,二聚体分子的β值与单体间距离和连接方式有关,在一定距离时出现极大值;而且,此类分子的β值具有显著的溶剂效应,但与单体间距离的依赖关系和气相中相同。由此可见,通过化学键改变单体间距离和连接方式可以作为提高有机分子NLO响应系数的有效途径。In recent years, experiments have shown that the relative arrangement and orientation of chromophores can be adjusted by bonds to enhance their nonlinear optical （NLO） responses. In this work, we choose the p-nitrophenol molecule as a monomer, and link them with chemical bonds to form a series of dimers with different inter-chromophore distances. Calculations with quantum chemistry methods revealed a close relationship of their first hyperpolarizability （,8） with the inter-chromophore distances, as well as with the linking modes, both in gas and solvent. A maximum ~ value at a certain inter-chromophore distance and significant solvent effect were noted for these dimers. Linking chromophores properly with chemical bonds is thus an effective way for enhancing their NLO responses.

关 键 词：一阶超极化率 分子间距离 溶剂效应 

分 类 号：O631.1[理学—高分子化学]