系列Ru(Ⅱ)配合物的DNA光裂解及光谱性质的理论研究

Theoretical studies on DNA-photocleavage and spectral properties of a series of Ru(Ⅱ) complexes

用密度泛函理论,对系列钌多吡啶配合物1-3的电子结构、DNA光裂解及光谱性质进行了研究.首先,计算了配合物1-3的氧化还原电势,根据配合物1-3激发态还原电势的大小,合理地解释了配合物1-3的DNA光裂解能力.其次,根据配合物1-3的电子结构性质,设计了具有较高激发态还原电势的配合物4,从理论上预测配合物4具有较强的光裂解能力.最后,用TDDFT方法,在水溶液中对配合物1-3的电子吸收光谱进行了计算和模拟,计算得到的电子吸收光谱和实验结果吻合较好,实验上测得的较强吸收带从理论上被详细地解释,并研究了配合物的主配体对电子吸收光谱性质的影响.

Theoretical studies of the electronic structures, DNA- photocleavage and spectral properties of a series of Ru （Ⅱ） polypyridyl complexes 1 - 3 have been carried out using the density functional theory. Firstly, the oxidation redox potentials of complexes 1 -3 were computed and the trend in the photocleavage abilities of these complexes was reasonably explained by their excited - state redox potentials. Secondly, complex 4 with a higher excited - state reductive potential was designed based on the electronic - structure properties of complexes 1 - 3, and the complex 4 with stronger DNA photocleavage ability was predicted. Finally, the electronic absorption spectra of complexes 1 -4 were computed and simulated in aqueous solution using the time dependent DFT （TDDFT） method, and the calculated absorption spectra of these complexes are in satisfying agreement with the experimental ones. Moreover, the intense experimental absorption bands of these complexes are theoretically explained in detail and the effect of the main ligands on the electronic absorption spectra was also investigated.