摘要
采用B3LYP方法在6-31G*水平上优化了6种F,Cl和Br取代的咪唑类衍生物分子几何构型,在此基础上采用TD-DFT的方法计算了它们的前线轨道能级和电子光谱,并用CPHF方法研究了此类衍生物二阶非线性光学系数性质.计算结果表明:此类化合物具有平面结构,共轭性较强;分子内设计的推拉电子基团增强分子内电荷转移,使前线分子轨道间的电子跃迁更容易;各体系具有较大的vβec和良好的透明性;咪唑环的引入增强了体系的热稳定性.这些结论对分子设计具有一定的指导意义.
At the 6-31G^＊ level, B3LYP method was employed to optimize the geometrical structures of six kinds of imidazole derivatives substituted by F,Cl and Br. TD-DFT method was adopted to calculate their energy levels of frontier orbitals and their eletronic spectrum. The nonlinear optical coefficient-βvec for the series of the derivatives was studied by using CPHF method. The calculations suggest that these compounds,with strong conjugation,have planar structures. Secondly, the push-pull electronic groups designed in molecules reinforce the charge transfer,making it easy to transit for the electrons in the frontier molecular orbitals. Thirdly, each system has large/β and good transparency. Fourthly, the introduction of imidazole reinforces the system＇s thermal stability.
出处
《分子科学学报》
CAS
CSCD
2006年第5期323-326,共4页
Journal of Molecular Science
基金
国家自然科学基金资助项目(20060307)
