【摘要】 目的运用量子化学计算为苯乙烯基苯并咪唑染料分子的结构与性质关系,以及染料的设计及合成提供理论依据。方法采用PBE1PBE和B3LYP两种密度泛函理论(DFT)方法及6-31G*极化基组对染料分子进行量化计算。结果对α-甲基-2-取代苯乙烯基苯并咪唑染料系列进行了几何构型全优化,并采用含时密度泛函方法(TD-DFT)计算了分子第一激发态的电子跃迁,计算所得到的最大吸收波长λmax与实验值吻合得很好,在微观上解释了苯环上取代基CH3,OH,Cl,OCH3,N(CH3)2,NO2对分子电荷转移,前线轨道能量和电子光谱的影响规律。结论采用PBE1PBE/6-31G*方法可以计算并预测苯乙烯基苯并咪唑系列染料分子的几何构型和电子吸收光谱性质。更多还原

【Abstract】 Aim To study the relationship between the structural properties and absorption properties of a series of α-methyl-2-substituted styryl benzimidazole dyes,and provide theoretical methods in designing and synthesizing dyes by theoretical calculations.Methods Using the density functional theory(DFT) at the PBE1PBE/6-31G* and B3LYP/6-31G* levels calculate the ground-state geometries,the lowest energy transitions and the absorption spectra of seven α-methyl-2-substitute styryl benzimidazole dyes.Results On this basis the first excited state electronic transition energy was calculated,and λmax was obtained,which accords quite well with the available experimental data.The effects of CH3,OH,Cl,OCH3,N(CH3)2 and NO2 on the molecular charge transfer,energies of frontier molecular orbitals and electronic spectra were investigated theoretically and explained micromechanically.Conclusion PBE1PBE/6-31G* appears as a excellent method for calculating and investigating the geometric structures and absorption properties of styryl benzimidazole dyes.更多还原