论文部分内容阅读
本文采用引入外场微扰的CNDO/S-CI方法,计算了一系列取代共轭多烯分子的二阶非线性光学系数β_(vec),探讨了取代基及共轭链长与分子微观非线性光学效应的关系和规律.结果表明:吸电子或供电子基团的引入,有利于增强分子的微观非线性光学效应,但该效应随取代基数目增多有减缓的趋势,“饱和”取代时由于“饱和效应”而使β_(vec)值降低;取代基间的距离增大,分子的β_(vec)值提高,端基取代时β_(vec)值最大;取代共轭多烯的lnβ_(vec)与分子中所含双键数n之间具有线性关系.本文还对上述结论给出了理论解释.
In this paper, the second order nonlinear optical coefficient β vec of a series of substituted conjugated polyene molecules has been calculated using the CNDO / S-CI method with field perturbation. The effects of substituent and conjugate chain lengths on the microscopic nonlinearity The results show that the introduction of electron-withdrawing or electron-donating groups can enhance the micro-nonlinear optical effect of the molecule, but this effect tends to slow down with the increase of the number of substituents. The substitution of “saturated” The value of β_ (vec) increases with the increasing of the distance between substituents, and the value of β_ (vec) increases with the substitution of terminal groups. ) Has a linear relationship with the number of double bonds n contained in the molecule.The paper also gives a theoretical explanation for the above conclusion.