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 devi...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 solventdependent,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.展开更多
基金the National Science Foundation(Grant No.CHE-1846831)the Welch Foundation(Grant No.E-1887)for funding this research.
文摘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 solventdependent,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.
