共轭单元调控三苯胺类敏化染料电子激发性质的计算研究

Computational study on the control of electron excitation properties of triphenylamine sensitized dye

为了增强传统乙烯键π桥的拉电子能力,针对经典D-A-π-A型三苯胺基敏化染料在电荷转移过程中的分子内回流现象,通过在额外受体苯并噻二唑和π桥乙烯之间增加苯、噻吩、呋喃和吡咯等共轭单元设计了4个新的染料分子,基于第一性原理计算探究了共轭单元对染料RL1激发态的调控作用。结果表明,苯并噻二唑在起到额外受体电子推拉作用的同时,由于较强的吸电子能力,导致一定的电子回流;设计的4种染料分子与RL1染料相比,苯、噻吩、呋喃和吡咯既减弱了苯并噻二唑的吸电子能力,又起到了一定的电子供体作用,明显增强了氰基乙酸基团的吸电子能力。在染料分子的设计和合成中,研究结果可为进一步提升染料的光电转化效率提供理论依据。

In order to enforce the electron withdrawn ability of traditional ethylene bondπbridge,focusing on the intramolecular reflux phenomenon in the electron transfer process of the classical D-A-π-A triphenylamine sensitized dye RL1,four different conjugated units,including benzene,thiophene,oxole,and pyridine,were added separately between the additional receptor Benzothiadiazole andπ-bridge.Then the control regulation of the excitation property of dye RL1 was investigated based on First Principle Calculation.The results show that Benzothiadiazole could push and pull on the electron as the extra receptor.However,due to the strong electron-withdrawing ability of benzothiadiazole,the electron reflux will happen in the electron transfer process.Compared with dye RL1,the four conjugated units not only weaken the electron-withdrawing ability of benzothiadiazole,but also play a role as an electron donor,so the electron-withdrawing ability of cyanoacetic acid group can be significantly enhanced.So the research result can provide theoretical basis for further improving the photoelectric transformation efficiency of dyes in the design and preparation of dye molecules.