Ir(III) complexes are particularly noted for their excellent photophysical properties in giving blue OLED phosphors. In this study, two distinctive carbene pro-chelates LAH2+ and LBH2+ (or LCH2+) were employed in preparation of heteroleptic Ir(III) complexes, to which LAH2+ bears a cyano substituted benzoimidazolium along with N-mesityl appendage, while LBH2+ (or LCH2+) carries the symmetrical benzoimidazolium entity. Notably, the reversible equilibration at high temperature was observed for m, f-ct14 and m, f-ct15 with a single LA chelate. In contrast, only the mer-substituted m-ct16 was obtained upon employing two LA chelates. All Ir(III) complexes exhibited blue photoluminescence (ΦPL ≥ 78%) with short radiative lifetimes (τrad ≤ 1.05 µs) in solution. The Ph OLED device with m-ct16 afforded an external quantum efficiency (EQE) of 22.8% at 5000 cd m‒2. Moreover, the hyper-OLED based on m-ct16 and v-DABNA exhibited EQE1000 of 32.1% (EQE recorded at 1000 cd·m-2) and J90 of 15.0 mA cm‒2 (current density at 90% of max. EQE). Its suppressed efficiency roll-off (EQE of 32.1% and 27.7% at 1000 cd·m‒2 and 10000 cd·m‒2) demonstrated a milestone in fabrication of blue OLED devices.
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http://dx.doi.org/10.1002/anie.202421664 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
City University of Hong Kong, Materials Sciences and Engineering, 83 Tat Chee Road, Kowloon, 999077, Kowloon Tong, HONG KONG.
Ir(III) complexes are particularly noted for their excellent photophysical properties in giving blue OLED phosphors. In this study, two distinctive carbene pro-chelates LAH2+ and LBH2+ (or LCH2+) were employed in preparation of heteroleptic Ir(III) complexes, to which LAH2+ bears a cyano substituted benzoimidazolium along with N-mesityl appendage, while LBH2+ (or LCH2+) carries the symmetrical benzoimidazolium entity. Notably, the reversible equilibration at high temperature was observed for m, f-ct14 and m, f-ct15 with a single LA chelate.
View Article and Find Full Text PDFDalton Trans
January 2025
Departamento de Química Inorgánica, Universidad de Murcia, Biomedical Research Institute of Murcia (IMIB-Arrixaca), E-30100 Murcia, Spain.
Activating photosensitizers with long-wavelength excitation is an important parameter for effective photodynamic therapy due to the minimal toxicity of this light, its superior tissue penetration, and excellent spatial resolution. Unfortunately, most Ir(III) complexes suffer from limited absorption within the phototherapeutic window, rendering them ineffective against deep-seated and/or large tumors, which poses a significant barrier to their clinical application. To address this issue, several efforts have been recently made to shift the absorption of Ir(III) photosensitizers to the deep-red/near-infrared region by using different strategies: functionalization with organic fluorophores, including porphyrinoid compounds, and ligand design π-extension and donor-acceptor interactions.
View Article and Find Full Text PDFInorg Chem
January 2025
Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education; Yunnan Provincial Center for Research and Development of Natural Products; School of Pharmacy, Yunnan University, Kunming 650500, P. R. China.
A series of dinuclear Ir(III) complexes have been constructed for enhanced photodynamic and photothermal therapy (PDT and PTT) for cisplatin-resistant non-small-cell lung cancer. They enter cells via caveolar endocytosis, target mitochondria but not nuclear, generate both singlet oxygen and superoxide anion, and release heat when exposed to infrared (IR) irradiation, thus inducing reactive oxygen species (ROS)-associated cell disruption and thermal ablation. The IR-generated ROS can further activate caspases, triggering apoptosis.
View Article and Find Full Text PDFMolecules
December 2024
Key Laboratory of Nanobiosensing and Nanobioanalysis at Universities of Jilin Province, Department of Chemistry, Northeast Normal University, 5268 Renmin Street, Changchun 130024, China.
Phosphorescent sensors are essential for rapid visual sensing of volatile acids, due to their profound impact on ecosystems and human health. However, solid phosphorescent materials for acid-base stimulus response are still rare, and it is important to achieve real-time monitoring of volatile acids. In order to obtain an efficient and rapid response to volatile acid stimulation, N-H and -NH substituents are introduced into an auxiliary ligand to synthesize a new cationic Ir(III) complex ().
View Article and Find Full Text PDFACS Omega
December 2024
Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
Since the 1980s, pressure-sensitive paint (PSP) has been used as an optical pressure sensor for measuring surface pressure on aircraft models in wind tunnels. Typically, PSPs have utilized platinum(II)-5,10,15,20-tetrakis(2,3,4,5,6-pentafluorophenyl)-porphyrin due to its high pressure sensitivity, phosphorescence lifetime of ∼50 μs, reasonable quantum yield of emission, and resistance to photo-oxidation. This work investigates the photophysics and electronic structure of metal complexes of 5,10,15,20-tetrakis(2,3,4,5,6-pentafluorophenyl)-porphyrin, namely, Zn(II), Pd(II), and Ir(III), as potentially improved luminophores for polymer-based PSPs.
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