ABAB型酞菁衍生物取代基对结构和电子光谱的影响

The Effects of Different Substituents on the Structure and Electronic Spectrum of ABAB-type Phthalocyanine

采用DFT方法在B3LYP/6-31G*水平上比较了ABAB型酞菁衍生物的几何结构,在此基础上用TDDFT方法计算了激发态,研究了ABAB型酞菁具有不同取代基对其电子结构和电子吸收光谱的影响.结果表明,3,6-(3',5'-双三氟甲基/三甲基)苯基的加入,前线轨道能级裂分导致Q带红移并出现了不同程度的裂分,Qx吸收带均红移,三氟甲基使Qy带蓝移.这种大的取代基在可见光区谱带的调制功能可以有效提高敏化剂的光捕获效率,为新型高效染料分子的设计提供理论指导.

The molecular geometries,electronic structures of ABAB-type Zn（ II） phthalocyanine compounds were investigated using the B3 LYP method within a framework of density functional theory（ DFT）. The excitation energies of these molecules were computed by the time-dependent DFT（ TD-DFT） methods. The calculated results of three compounds reflect the interpolation of bulky 3,6-（ 3＇,5＇-bis（ trifluoromethyl / methyl） phenyl） phthalonitrile results in a red shift of the Q band and a different splitting degree. The specific performance can be described as the red shift of their Qxband and the blue shift of Qyband of phthalocyanine derivatives with trifluorine methyl groups. Large substituents with adjustment function in the visible region can effectively improve the light harvesting efficiency of sensitizer,which provides theoretical guidance for design of high efficient dyes.