Homoleptic Ir_((III))based carbene complexes are known to be the most promising emitters of future blue OLED devices.To provide the proof-of-concept,we designed a series of functional di-CF_(3)-functionalized benzo[d]...Homoleptic Ir_((III))based carbene complexes are known to be the most promising emitters of future blue OLED devices.To provide the proof-of-concept,we designed a series of functional di-CF_(3)-functionalized benzo[d]imidazol-3-ium pro-chelates,which could afford single product emitters after proper modification.For benzoimidazol-2-ylidene with an N-methyl substituent,selective formation of the product can be achieved by introduction of t-butylphenyl for the phenyl group,as shown by shifting the product from mixed m-Ir(dfp)_(3)and f-Ir(dfp)_(3)to the single isomer f-Ir(dfpb)_(3).Alternatively,for di-N-aryl substituted carbene chelates,the steric encumbrance imposed between the ortho-CF_(3)group and the adjacent N-aryl substituent redirects the cyclometalation to the other N-aryl substituent,leading to the formation of one single product,e.g.,f-Ir(tBpp)_(3)and f-Ir(ptBp)_(3).Moreover,the doped OLED based on f-Ir(tBpp)_(3)delivered true-blue emission centered at 457 nm and a maximum EQE of 15.6%.Furthermore,upon addition of terminal emittersν-DABNA and t-DABNA,the respective hyper^(-)OLEDs exhibited narrowband blue emission with a maximum EQE of 18.9%at 474 nm and 18.1%at 462 nm,respectively.These highlighted the potential of these Ir_((III))emitters in the fabrication of blue OLEDs.展开更多
Third-row transition-metal complexes remain a key component in the preparation of light-emitting layers for future OLED technology.Hence,it is of utmost importance to expand their emission peak wavelengths into the tr...Third-row transition-metal complexes remain a key component in the preparation of light-emitting layers for future OLED technology.Hence,it is of utmost importance to expand their emission peak wavelengths into the true-blue(~460–470 nm)and near-infrared(NIR)regions(~700–1000 nm).Stable true-blue phosphors are expected to excel in commercially available lighting luminaries and visual devices,such as displays and monitors,while efficient NIR emitters will enable new applications such as sensing,imaging,and optical communication.In theory,these advanced emitters can be assembled using transition metals such as iridium and platinum and judiciously designed chelates,as elaborated in this chemistry frontier article.展开更多
基金supported by funding from the Research Grant Council(CityU 11304221 and CityU 11312722)the City University of Hong Kong,Hong Kong SAR。
文摘Homoleptic Ir_((III))based carbene complexes are known to be the most promising emitters of future blue OLED devices.To provide the proof-of-concept,we designed a series of functional di-CF_(3)-functionalized benzo[d]imidazol-3-ium pro-chelates,which could afford single product emitters after proper modification.For benzoimidazol-2-ylidene with an N-methyl substituent,selective formation of the product can be achieved by introduction of t-butylphenyl for the phenyl group,as shown by shifting the product from mixed m-Ir(dfp)_(3)and f-Ir(dfp)_(3)to the single isomer f-Ir(dfpb)_(3).Alternatively,for di-N-aryl substituted carbene chelates,the steric encumbrance imposed between the ortho-CF_(3)group and the adjacent N-aryl substituent redirects the cyclometalation to the other N-aryl substituent,leading to the formation of one single product,e.g.,f-Ir(tBpp)_(3)and f-Ir(ptBp)_(3).Moreover,the doped OLED based on f-Ir(tBpp)_(3)delivered true-blue emission centered at 457 nm and a maximum EQE of 15.6%.Furthermore,upon addition of terminal emittersν-DABNA and t-DABNA,the respective hyper^(-)OLEDs exhibited narrowband blue emission with a maximum EQE of 18.9%at 474 nm and 18.1%at 462 nm,respectively.These highlighted the potential of these Ir_((III))emitters in the fabrication of blue OLEDs.
基金supported by research funds from Innovation and Technology Fund(ITS/196/20)Research Grant Council(CityU 11304221 and 11312722)City University of Hong Kong,Hong Kong SAR.
文摘Third-row transition-metal complexes remain a key component in the preparation of light-emitting layers for future OLED technology.Hence,it is of utmost importance to expand their emission peak wavelengths into the true-blue(~460–470 nm)and near-infrared(NIR)regions(~700–1000 nm).Stable true-blue phosphors are expected to excel in commercially available lighting luminaries and visual devices,such as displays and monitors,while efficient NIR emitters will enable new applications such as sensing,imaging,and optical communication.In theory,these advanced emitters can be assembled using transition metals such as iridium and platinum and judiciously designed chelates,as elaborated in this chemistry frontier article.
