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Title: Enhanced deep red to near-infrared (DR-NIR) phosphorescence in cyclometalated iridium( iii ) complexes
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.  more » « less
Award ID(s):
1846831
NSF-PAR ID:
10399468
Author(s) / Creator(s):
;
Date Published:
Journal Name:
Inorganic Chemistry Frontiers
Volume:
9
Issue:
24
ISSN:
2052-1553
Page Range / eLocation ID:
6544 to 6553
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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