Department of Chemistry, Bengbu Medical College, Donghai Avenue, Bengbu, Anhui, 233030, P. R. China.
Department of Chemistry, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, P. R. China.
Dalton Trans. 2023 Sep 13;52(35):12444-12453. doi: 10.1039/d3dt02104a.
We report herein the design, synthesis and characterisation of a series of luminescent iridium(III) porphyrin complexes [Ir(ttp)(CHCHOH)] (Http = 5,10,15,20-tetra-4-tolylporphyrin) (1), [Ir(tpp-Ph-NO)(CO)Cl] (Htpp-Ph-NO = 5-(4-((4-nitrophenoxy)carbonyloxymethyl)phenyl)-10,15,20-triphenylporphyrin) (2), Ir(tpp-COOMe)(Py) (Htpp-COOMe = 5-(4-methoxycarbonylphenyl)-10,15,20-triphenylporphyrin; Py = pyridine) (3) and Ir(tpp-COOH)(Py) (Htpp-COOH = 5-(4-carboxylphenyl)-10,15,20-triphenylporphyrin) (4). All the complexes displayed long-lived near-infrared (NIR) emission attributed to an excited state of mixed triplet intraligand (IL) (π → π*) (porphyrin) and triplet metal-to-ligand charge transfer (MLCT) (dπ(Ir) → π*(porphyrin)) character. The cytotoxicity of the complexes toward HeLa cells was examined by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cationic complexes 3 and 4 exhibited higher cytotoxic activity toward HeLa cells than their neutral counterparts 1 and 2. Cellular uptake studies by inductively coupled plasma-mass spectrometry (ICP-MS) and laser-scanning confocal microscopy (LSCM) indicated that complexes 3 and 4 showed higher cellular uptake efficiencies than complexes 1 and 2 due to their cationic charge, and they were enriched in the perinuclear region of the cells with negligible nuclear uptake. Additionally, the carboxyl complex 4 was used to label a model protein bovine serum albumin (BSA) an amidation reaction. The resultant luminescent protein conjugate 4 displayed similar photophysical properties and intracellular localisation behaviour to its parent complex. The results of this work will contribute to the development of luminescent iridium(III) porphyrin complexes and related bioconjugates as NIR-emissive probes for bioimaging applications.
我们在此报告了一系列发光铱（III）卟啉配合物 [Ir(ttp)(CHCHOH)]（Http = 5,10,15,20-四-4-甲苯基卟啉）（1）、[Ir(tpp-Ph-NO)(CO)Cl]（Htpp-Ph-NO = 5-(4-((4-硝基苯氧基)羰基氧甲基)苯基）-10,15,20-三苯基卟啉）（2）、Ir(tpp-COOMe)(Py)（Htpp-COOMe = 5-(4-甲氧羰基苯基)-10,15,20-三苯基卟啉；Py = 吡啶）（3）和 Ir(tpp-COOH)(Py)（Htpp-COOH = 5-(4-羧基苯基)-10,15,20-三苯基卟啉）（4）的设计、合成和表征。所有配合物都显示出长寿命的近红外（NIR）发射，归因于混合三重态内 ligand（IL）（π → π*）（卟啉）和三重态金属到 ligand 电荷转移（MLCT）（dπ（Ir）→π*（卟啉））的激发态。通过 3-(4,5-二甲基-2-噻唑基）-2,5-二苯基四唑溴化铵（MTT）测定法检查了配合物对 HeLa 细胞的细胞毒性。阳离子配合物 3 和 4 对 HeLa 细胞的细胞毒性高于其中性对应物 1 和 2。电感耦合等离子体质谱（ICP-MS）和激光扫描共聚焦显微镜（LSCM）的细胞摄取研究表明，由于其正电荷，配合物 3 和 4 具有更高的细胞摄取效率，并且它们在细胞的核周区域富集，核摄取可忽略不计。此外，羧基配合物 4 用于标记模型蛋白牛血清白蛋白（BSA）的酰胺化反应。所得发光蛋白缀合物 4 显示出与其母体配合物相似的光物理性质和细胞内定位行为。这项工作的结果将有助于开发近红外发光铱（III）卟啉配合物和相关生物缀合物作为生物成像应用的 NIR 发射探针。
