6-羟基-5,12-萘并萘醌及其CH3, C6H5取代衍生物的光致变色理论研究

用密度泛函理论的B3LYP/6-31G方法和从头算的CIS/6-31G方法分别研究了6-羟基-5,12-萘并萘醌及其CH₃, C₆H₅取代衍生物基态和激发态的异构化反应，.对反应势能面的研究发现, 在光异构化反应中化合物M21和M21、M31的基态和激发态虽然都可以构成四能级反应过程, 但由于M21异构化过程的活化能较高, 使其所构成的四能级反应难以进行, 这就从理论上解释了迁移基团为甲基的M21变色性能低于迁移基团为苯基的M31的实验结果. 此外用TD/B3LYP方法在溶剂存在下计算了上述化合物的紫外吸收光谱和荧光发射光谱, 计算所得到的光谱数据与实验值基本一致, 与光异构化反应的光激发条件相符合.

Theoretical Investigation of Photochromic Reactions of 6-Hydroxy-5,12-naphthacenequinone and Its Derivatives Bearing Methyl or Phenyl Groups

Photoisomerizations of 6-hydroxy-5,12-naphthacenequinone and its derivatives bearing methyl and phenyl group were theoretically investigated with density functional theory method and ab initio CIS method at the B3LYP 6-31G basis set,respectively. The obtained potential energy curves disclosed that a four-state cycle existed in the ground and excited states. It was also found that the activation energy for the methyl transfer was higher compared to the phenyl transfer,which was consistent to the experimental results that the photoisomerization of the phenyl substituted derivative was more rapid than the methyl substituted derivatives. Further hybrid time-dependent density functional theory (TD-DFT) was used to investigate the absorption and fluorescence spectra of these compounds under solvent effect condition. The calculated val-ues were in agreement with the experimental results and the excitation condition of photochromic reactions.