取代肉桂酸异构体的稳定性和二阶非线性光学性质的DFT研究  

DFT study on the stabilities and second-order nonlinear optical properties of the cinnamic acid isomers

作　　者：谭克[1] 

机构地区：[1]长春大学环境生态工程学院,吉林长春130022

出　　处：《东北师大学报（自然科学版）》2005年第2期72-75,共4页Journal of Northeast Normal University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(20243003)

摘　　要：　采用量子化学B3LYP/6-31G 方法对6种取代肉桂酸异构体分子的几何构型进行优化,通过计算比较了其稳定性、前线分子轨道和二阶非线性光学(NLO)系数.结果表明:肉桂酸异构体分子Ⅰ—Ⅵ中,—NH2和—NO2与甲氧基处于间位的异构体最稳定;前线分子轨道能级差顺序为ΔEg(Ⅰ)>ΔEg(Ⅱ)>ΔEg(Ⅲ)和ΔEg(Ⅳ)<ΔEg(Ⅴ)<ΔEg(Ⅵ);6个肉桂酸异构体分子的|βμ|值与典型共轭有机分子相似,表现出良好的二阶NLO活性.由于甲氧基与引入基团的给、吸电子性质相互作用,—NH2和甲氧基处于邻位的异构体二阶NLO系数最大,而—NO2和甲氧基处于对位的异构体二阶NLO系数最大.<Abstrcat>The geometric structures of cinnamic acid isomers were optimized with quantum chemistry B3LYP/6-31G* method.The stabilities and frontier molecular orbitals as well as second-order nonlinear optical coefficients were obtained.The results show that for the six isomers of cinnamic acid, the most stable isomer is the compound that —NH2 and —NO2 locate on the metra position with methyl.The sequence of the frontier molecular orbital is as follows: ΔEg(Ⅰ) >ΔEg(Ⅱ)>ΔEg(Ⅲ)和ΔEg(Ⅳ)<Δ Eg(Ⅴ)< ΔEg(Ⅵ).The |βμ| value of the six isomers is similar to the typical conjugated organic molecules, so it also has good second-order activities.Owing to the interaction between the electron-donor methoxy and the imported groups, the highest second-order NLO coefficients happens on the isomers importing —NH2 when —NH2 stands on the ortho position, the same trend can be found for the isomers importing —NO2 when the methoxy locates on the para position.

关 键 词：肉桂酸 稳定性 二阶NLO DFT方法 

分 类 号：O641[理学—物理化学]