The outcomes of DFT‐based calculations are here reported to assess the applicability of two synthesized polypyridyl Ru(II) complexes, bearing ethynyl nile red (NR) on a bpy ligand, and two analogues, bearing modified‐NR, in photodynamic therapy. The absorption spectra, together with the non‐radiative rate constants for the S1 – Tn intersystem crossing transitions, have been computed for this purpose. Calculations evidence that the structural modification on the chromophore destabilizes the HOMO of the complexes thus reducing the H‐L gap and, consequently, red shifting the maximum absorption wavelength within the therapeutic window, up to 620 nm. Moreover, the favored ISC process from the bright state involves the triplet state closest in energy, which is also characterized by the highest SOC value and by the involvement of the whole bpy ligand bearing the chromophore in delocalising the unpaired electrons. These outcomes show that the photophysical behavior of the complexes is dominated by the chromophore.

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带有尼罗红发色团的钌配合物及其衍生物之一：PDT相关特性的理论评估

本文报道了基于 DFT 的计算结果，以评估两种合成的聚吡啶基 Ru(II) 配合物（在 bpy 配体上带有乙炔基尼罗红 (NR)）和两种类似物（带有修饰的 NR）在光动力疗法中的适用性。为此目的，计算了吸收光谱以及 S1 – Tn 系间跨越跃迁的非辐射速率常数。计算表明，发色团的结构修饰破坏了复合物 HOMO 的稳定性，从而减少了 H-L 间隙，从而使治疗窗口内的最大吸收波长发生红移，最高可达 620 nm。此外，来自亮态的受欢迎的ISC过程涉及能量最接近的三重态，其特征还在于最高的SOC值以及带有发色团的整个bpy配体参与使不成对电子离域。这些结果表明复合物的光物理行为由发色团主导。