Three mononuclear or dinuclear bis(terpyridine) (tpy) iridium(III) complexes bearing pyren-1-yl (pyr) group(s) were synthesized. Their photophysical properties in water and in vitro photodynamic therapy (PDT) effects toward the human lung epithelial cancer cell line A549 and the human epidermal skin cancer cell line A431 were investigated to evaluate the effects of dinuclear versus mononuclear complexes and the impact of the oligoether substituent at the ligand. All complexes possessed pyr–tpy ligand-associated charge transfer (¹CT)/¹π,π* absorption bands at 350–550 nm, with the dinuclear complex Ir3 showing the much enhanced absorptivity of this band. These complexes exhibited dual emission upon excitation at >430 nm in most cases, with the emitting states being ascribed to ¹ILCT (intraligand charge transfer) and ³π,π*/³CT states, respectively. All complexes exhibited relatively weak to moderate cytotoxicity in the dark but high photocytotoxicity upon broadband visible light irradiation. Among them, the dinuclear complex Ir3 showed the highest intracellular reactive oxygen species (ROS) generation and PDT efficiency compared to its mononuclear counterpart Ir1. Introducing an oligoether substituent on one of the tpy ligands in Ir2 also improved its intracellular ROS generation and PDT efficacy compared to those induced by Ir1. Ir3 induced both mitochondrial dysfunction and lysosomal damage upon light activation toward both cell lines, whereas Ir1 and Ir2 caused both mitochondrial dysfunction and lysosomal damage in A431 cells but only lysosomal damage in A549 cells. The dominant cell death pathway induced by Ir1–Ir3 PDT is apoptosis.

中文翻译：

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单核和双核铱（III）双（三联吡啶）配合物的体外光动力治疗

合成了三个单核或双核双(三联吡啶) (tpy) 铱 (III) 配合物，它们带有 pyren-1-yl (pyr) 基团。研究了它们在水中的光物理特性和体外光动力疗法 (PDT) 对人肺上皮癌细胞系 A549 和人表皮皮肤癌细胞系 A431 的影响，以评估双核与单核复合物的影响以及低聚醚取代基的影响在配体。所有配合物都具有 pyr-tpy 配体相关的电荷转移 ( ¹ CT)/ ¹ π , π* 吸收带在 350-550 nm，与双核配合物Ir3显示该波段的吸收率大大提高。在大多数情况下，这些配合物在 > 430 nm 处激发时表现出双重发射，发射状态分别归因于¹ ILCT（配体内电荷转移）和³ π,π*/ ³ CT 状态。所有复合物在黑暗中表现出相对较弱至中等的细胞毒性，但在宽带可见光照射下表现出较高的光细胞毒性。其中，与单核对应物 Ir1 相比，双核复合物Ir3显示出最高的细胞内活性氧 (ROS) 生成和 PDT 效率。在Ir2中的一个 tpy 配体上引入一个低聚醚取代基与Ir1诱导的相比，还改善了其细胞内 ROS 的产生和 PDT 功效。Ir3在光激活两种细胞系时诱导线粒体功能障碍和溶酶体损伤，而Ir1和Ir2在 A431 细胞中引起线粒体功能障碍和溶酶体损伤，但仅在 A549 细胞中引起溶酶体损伤。Ir1-Ir3 PDT诱导的主要细胞死亡途径是细胞凋亡。