摘要
采用DFT//B3LYP方法,在6-31G基组上对咔唑及其衍生物基态结构进行了优化.计算得到键长、键角、HOMO、LUMO能级.在基态几何优化基础上,用含时密度泛函理论(TD-DFT)计算了吸收光谱,并分析了取代基对咔唑的影响及变化规律.计算结果表明:取代基对键长、键角的影响很小;供电子基使得HOMO和LUMO轨道能量升高,但能隙下降;吸电子基使得咔唑的共轭性程度增强,能隙降低;无论吸电子基团还是推电子基团均使吸收光谱较咔唑发生了红移.
The ground-state geometries of carbazole and its derivatives were optimized using DFT/B3LYP method at the 6-31G basis set,as implemented in Gaussian 03.And the bond length,bond angle,HOMO,LUMO orbitals and energy levels were obtained.The absorption spectra and the excitation energies were abtained using the time density functional theory（TD-DFT）,6-31G base set,at the optimized geometries of the ground states.And the influence of substituting bases to the carbazole are then analyzed.The computed results indicated that the bond length and bond angle are influenced very slightly by substituting bases.Power supply subbasis cause HOMO、LUMO orbital energies to elevate,but make the energy gaps drop relatively.Attracts the electricity subbasis cause the conjugational degree of carbazole to strengthen,but make the energy gaps to drop relatively.Power supply subbasis and attracts the electricity subbasis both make absorption spectra red shift.And absorption spectra are influenced very slightly by alkylations substituting bases on 4 of carbazole.As the same substituting group,the influence to absorption spectra of substituting bases on 9 of carbazole are bigger than substituting bases on 4 of carbazole.
出处
《东北师大学报（自然科学版）》
CAS
CSCD
北大核心
2011年第4期96-100,共5页
Journal of Northeast Normal University(Natural Science Edition)
基金
吉林省科技发展计划项目(20111814)
作者简介
[作者简介]刘鸿雁（1973-），女，硕士，讲师，主要从事物理化学研究
