光克洛及其富勒烯复合物光敏性的理论计算

Density Functional Calculation on the Optical Absorption Properties of HPPH-Fullernene Dyads

基于密度泛函(DFT)及其时间依赖相关理论(TD-DFT),对应用于光动力疗法的临床光敏剂光克洛(HPPH)与富勒烯C_(60)的3种复合物的基态和激发态性质进行了计算。通过对复合物的几何结构、结合能、电荷布局的计算分析发现,C_(60)与光克洛的卟啉氮原子相互作用的结合能和电荷转移程度较大。对复合物的激发能进行了计算并对吸收光谱进行了模拟,结果显示C_(60)与光克洛复合后降低了最低占据轨道的能量和前线轨道能级间隔,导致复合物的激发能降低,最大吸收峰红移,其中复合物HPPH-C_(60)(1)的最大吸收峰达到了961.69 nm的近红外区。

Based on density functional theory （DFT） and time dependent theory （TD-DFT）, the ground state and the excited state properties of the clinical photosensitizer （HPPH and HPPH-C60 dy- ads） applied in photodynamic therapy have been calculated. From the results of the optimized geomet- ric structures, the binding energies and the charges populations, it can be found that the different bind- ing sites between C60 and HPPH induce the different binding energy. The maximum binding energy and the significant charge transfer occur at C6o and porphyrin nitrogen atoms of HPPH in HPPH-C^o（1）. At the same time, the excited energies and the absorption spectra of three HPPH-C6~ dyads were calculated by TD-DFT. The results show that the C60 can reduce the low occupied orbital energies and the low fron- tier orbital energy gaps, which leads to the decrease of the excitation energy and the red-shift of maxi- mum absorption peak in three HPPH-C60 dyads. Especially, the maximum absorption peak of the HPPH-C6o（1） reaches near infrared 96 1.69 nm.