Caporale Chiara, Bader Christie A, Sorvina Alexandra, MaGee Karen D M, Skelton Brian W, Gillam Todd A, Wright Phillip J, Raiteri Paolo, Stagni Stefano, Morrison Janna L, Plush Sally E, Brooks Douglas A, Massi Massimiliano
Curtin Institute of Functional Molecules and Interfaces and Department of Chemistry, Curtin University, Kent Street, Bentley, 6102 WA, Australia.
Mechanisms in Cell Biology and Disease Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia.
Chemistry. 2017 Nov 7;23(62):15666-15679. doi: 10.1002/chem.201701352. Epub 2017 Aug 7.
A family of five neutral cyclometalated iridium(III) tetrazolato complexes and their methylated cationic analogues have been synthesised and characterised. The complexes are distinguished by variations of the substituents or degree of π conjugation on either the phenylpyridine or tetrazolato ligands. The photophysical properties of these species have been evaluated in organic and aqueous media, revealing predominantly a solvatochromic emission originating from mixed metal-to-ligand and ligand-to-ligand charge transfer excited states of triplet multiplicity. These emissions are characterised by typically long excited-state lifetimes (∼hundreds of ns), and quantum yields around 5-10 % in aqueous media. Methylation of the complexes caused a systematic red-shift of the emission profiles. The behaviour and the effects of the different complexes were then examined in cells. The neutral species localised mostly in the endoplasmic reticulum and lipid droplets, whereas the majority of the cationic complexes localised in the mitochondria. The amount of complexes found within cells does not depend on lipophilicity, which potentially suggests diverse uptake mechanisms. Methylated analogues were found to be more cytotoxic compared to the neutral species, a behaviour that might to be linked to a combination of uptake and intracellular localisation.
已合成并表征了一个由五个中性环金属化铱（III）四唑配合物及其甲基化阳离子类似物组成的家族。这些配合物的区别在于苯基吡啶或四唑配体上取代基的变化或π共轭程度。已在有机和水性介质中评估了这些物质的光物理性质，结果表明主要是源于三线态多重性的混合金属到配体和配体到配体电荷转移激发态的溶剂化显色发射。这些发射的特征通常是激发态寿命较长（约数百纳秒），在水性介质中的量子产率约为5-10%。配合物的甲基化导致发射光谱发生系统性红移。然后在细胞中研究了不同配合物的行为和影响。中性物质大多定位于内质网和脂滴中，而大多数阳离子配合物定位于线粒体中。细胞内发现的配合物数量并不取决于亲脂性，这可能表明存在多种摄取机制。与中性物质相比，甲基化类似物具有更高的细胞毒性，这种行为可能与摄取和细胞内定位的组合有关。
