摘要
采用密度泛函理论(DFT)B3LYP/6-31G方法,对设计的6个不同位置取代氨基的香豆素衍生物的几何构型进行优化。在所得优化结构基础上对这些分子的稳态二阶NLO系数β值进行计算分析,并采用含时密度泛函理论(TD-DFT)方法计算了其电子性质,研究了取代位置对香豆素类衍生物分子的二阶NLO性质的影响规律。结果表明:当氨基取代在4号位时香豆素分子中的羰基表现出供电性,对分子内电荷转移非常不利,不利于提高分子的β值;当氨基取代在3、5、6、7、8位时分子中的羰基表现出吸电性,使分子形成D-π-A构型,并且氨基在3、7位的取代能够扩大体系的共轭范围,有效增加了香豆素分子的β_(tot)值。
The density functional theory（DFT） B3LYP method based on the 6-31G level was employed to optimize the geometric structures of six amino coumarin derivatives.On the basis of obtaining stable molecular configuration,combined with time-dependent density functional theory（TD-DFT）,the static second-order nonlinear optic polarizabilities（β） and the molecular electric spectrum were calculated by the same method.The results indicated that when amino substitute at the fourth position of coumarin the carbonyl show electron donating property which is a disadvantage for intramolecular charge transfer. When amino substitute at the third,fifth,sixth,seventh and eighth position of coumarin the carbonyl show electron with drawing property which makes the molecule form D-π-A configuration.And the third and seventh position can expand the conjugate system of molecule which can increase theβtot value of coumarin effectively.
出处
《量子电子学报》
CAS
CSCD
北大核心
2012年第4期485-490,共6页
Chinese Journal of Quantum Electronics
关键词
非线性光学
二阶非线性效应
密度泛函
香豆素
取代位置
nonlinear optics； second-order nonlinear effect； density functional theory； coumarin； substitution position
