AIE-active Ir(iii) complexes functionalised with a cationic Schiff base ligand: synthesis, photophysical properties and applications in photodynamic therapy. Issue 42 (11th October 2022)

• Record Type: Journal Article
• Authors: Liu, Shengnan; Han, Jiahong; Wang, Weijin; Chang, Yulei; Wang, Runlin; Wang, Ziwei; Li, Guangzhe; Zhu, Dongxia; Bryce, Martin R.
• Is Part Of: Dalton transactions. Volume 51:Issue 42(2022)
• Page Start: 16119
• Page End: 16125
• Publication Date: 2022-10-11
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d2dt02960j
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Two AIE-active Ir(iii ) cationic complexes containing Schiff base ligands were synthesised. Ir-2-N + NPs are shown to be good PSs in vitro for PDT. Abstract : Photodynamic therapy (PDT) is a promising cancer treatment method. Traditional small-molecule photosensitizers (PSs) suffer from low intersystem crossing (ISC) ability and aggregation-caused quenching (ACQ), which adversely affects the luminous efficiency and singlet oxygen ( 1 O2 ) yield of PSs in the aggregated state. Ir(iii ) complexes are promising PSs with long excited-state lifetime, good photophysical and photochemical properties and large Stokes shifts. Aggregation-induced emission (AIE) characteristics could reduce the nonradiative recombination and improve the ISC ability of excited states through the restriction of the intramolecular motions in aggregated states. Accordingly, two AIE-active Ir(iii ) complexes Ir-1-N + and Ir-2-N + were successfully designed and obtained based on Schiff base ligands. Experimental results showed that Ir-1-N + and Ir-2-N + have good photophysical properties and the corresponding nanoparticles (NPs) have good water solubility and 1 O2 generation ability. Notably, Ir-2-N + NPs can be efficiently taken up by mouse breast cancer cells (4T1 cells) with good biocompatibility, low dark toxicity and excellent phototoxicity. This work demonstrates a versatile strategy for exploiting efficient transition metal PSs with a cationic ligand in PDT.