The design of deep-red to near-infrared (DR-NIR) phosphorescent compounds with high photoluminescence quantum yields ( Φ PL ) is a significant fundamental challenge that impacts applications including optoelectronic devices, imaging, and sensing. Here we show that bis-cyclometalated iridium complexes with electron-rich ancillary ligands can have exceptional quantum yields for DR-NIR phosphorescence (peak λ > 700 nm). Six bis-cyclometalated iridium( iii ) complexes with DR-NIR phosphorescence are described in this work, pairing highly conjugated cyclometalating ligands with electron-rich and sterically encumbered β-ketoiminate (acNac), β-diketiminate (NacNac), and N , N ′-diisopropylbenzamidinate (dipba) ancillary ligands. The photoluminescence spectra and quantum yields are solvent-dependent, consistent with significant charge-transfer character in the emissive excited state. The ancillary ligands perturb the excited-state kinetics relative to closely related compounds, which can lead to enhanced Φ PL values in the DR-NIR region, particularly in toluene solution and in doped polymer films.
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Efficient near-infrared luminescence from bis-cyclometalated iridium( iii ) complexes with rigid quinoline-derived ancillary ligands
Five new near-infrared (NIR) phosphorescent bis-cyclometalated iridium( iii ) complexes, partnering highly conjugated cyclometalating ligands with quinoline-derived ancillary ligands, have been developed. These complexes have peak NIR luminescence wavelengths from 711 to 729 nm, with photoluminescence quantum yields ranging from 0.042 to 0.36.
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- Award ID(s):
- 1846831
- NSF-PAR ID:
- 10317923
- Date Published:
- Journal Name:
- Chemical Communications
- Volume:
- 56
- Issue:
- 62
- ISSN:
- 1359-7345
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D0CC02745F
