Photoacoustic agents combining photodynamic therapy(PDT) and photothermal therapy(PTT) functions have emerged as potent theranostic agents for combating cancer. The molecular approaches for enhancing the near-infrared...Photoacoustic agents combining photodynamic therapy(PDT) and photothermal therapy(PTT) functions have emerged as potent theranostic agents for combating cancer. The molecular approaches for enhancing the near-infrared(NIR)-absorption and maximizing non-radiative energy transfer are essential for effective photoacoustic imaging(PAI) and therapy applications. In addition, such molecules with high specificity and affinity to cancer cells are urgently needed, which would further decrease the side effect during treatments. In this study, we applied a heavy-atom engineering strategy and introduced p-aminophenol,-thio, and-seleno moieties into NIR heptamethine cyanine(Cy7) skeleton(Cy7-X-NH_(2), X = O, S, Se) to significantly increase photothermal conversion efficiency for PTT and promote intersystem crossing for PDT.Additionally, we designed a series of nitroreductase(NTR)-activated photoacoustic probes(Cy7-X-NO_(2),X = O, S, Se), and target hypoxic tumors with NTR overexpression. Our prostate cancer targeting probe,Cy7-Se-NO_(2)-KUE, exhibited specific tumor photoacoustic signals and effective tumor killing through outstanding synergistic PTT/PDT in vivo. These findings highlighted a versatile strategy for cancer photoacoustic diagnosis and enhanced phototherapy.展开更多
To attain high efficiencies in hybrid white organic light-emitting diodes(WOLEDs),mutual quenching of the fluorophors and phosphors should be minimized.Efforts have been devoted to reducing the triplet quenching of ph...To attain high efficiencies in hybrid white organic light-emitting diodes(WOLEDs),mutual quenching of the fluorophors and phosphors should be minimized.Efforts have been devoted to reducing the triplet quenching of phosphors;however,the quenching of fluorophors by the external heavy-atom effect(EHA)introduced by the phosphors is often ignored.Here,we observed that conventional fluorophors and fluorophors with thermally activated delayed fluorescence(TADF)behave differently in the presence of EHA perturbers.The efficiencies of the conventional fluorophors suffer greatly from the EHA,whereas the TADF fluorophors exhibit negligible changes,which makes TADF materials ideal fluorophors for hybrid devices.WOLEDs using a blue TADF fluorophor and an orange phosphor achieve a maximum forward viewing external quantum efficiency of 19.6%and a maximum forward viewing power efficiency of 50.2 lm W^(-1),among the best values for hybrid WOLEDs.This report is the first time that the EHA effect has been considered in hybrid WOLEDs and that a general strategy toward highly efficient hybrid WOLEDs with simple structures is proposed.展开更多
The preparation of amorphous pure organic room-temperature phosphorescence materials with high efficiency is still a challenging task. Herein, we introduce a CB[6] derivative-based supramolecular selfassembling strate...The preparation of amorphous pure organic room-temperature phosphorescence materials with high efficiency is still a challenging task. Herein, we introduce a CB[6] derivative-based supramolecular selfassembling strategy. A water soluble and ellipsoidal deformed CB[6] derivative is used to self-assemble with 4-(4-bromophenyl)-1-methylpyridin-1-ium chloride, bromide and hexafluorophosphate in water. After freeze-drying, the obtained amorphous complexes exhibit brilliant green phosphorescence emission under ambient conditions, with phosphorescence efficiency up to 59%, 60% and 72%, respectively. This is the first report of amorphous non-polymeric pure organic room-temperature phosphorescence with such a high efficiency. In view of the dynamic self-assembling property, the complexes are responsive to water,which could enable information encryption.展开更多
While intramolecular cyclization effectively modulates photoelectronic properties of multi-resonance(MR)-thermally activated delayed fluorescence(TADF)emitters,simultaneous narrowing full width at half maxima(FWHM)of ...While intramolecular cyclization effectively modulates photoelectronic properties of multi-resonance(MR)-thermally activated delayed fluorescence(TADF)emitters,simultaneous narrowing full width at half maxima(FWHM)of spectra and accelerating reverse intersystem crossing(RISC)remain a formidable challenge.Here,we introduce a phosphorus-carbon-bridged cyclization in MR skeletons to synergistically suppress high-frequency molecular vibrations via skeleton rigidification and enhance spin-orbital coupling through introducing heavy-atom effects.Implementing this approach,two blue emitters,phenylphosphine oxide-bridged(BCzBN-PO)and phenylphosphine sulfide-bridged(BCzBN-PS),are developed and exhibit emission peaks at 467 and 474 nm with FWHMs of 19 and 18 nm,respectively.Moreover,benefiting from the additional heavy atom effect of sulfur complementing that of phosphorus,BCzBN-PS achieved a kRISC of 8.5×10^(5)s^(−1),nearly 8-fold higher than that of BCzBN-PO(1.1×10^(5)s^(−1)).In the non-sensitized device architecture,both emitters exhibited narrowband emission with a FWHM<30 nm and a maximum external quantum efficiency(EQE)>20%.Notably,BCzBN-PS,leveraging its higher upconversion rate,demonstrated a superior maximum EQE and lower efficiency roll-off.Furthermore,in the TADF-sensitized device configuration,the organic light-emitting diodes further validated the enhanced upconversion efficiency—evidenced by BCzBN-PS delivering a higher maximum EQE than BCzBN-PO(43.0%vs.41.2%)and a reduced efficiency roll-off(30.1%vs.25.9%at 1000 cd m−2).This work establishes a molecular engineering paradigm that balances color purity and exciton utilization efficiency,paving new avenues for high-performance narrowband electroluminescence.展开更多
Despite great achievements obtained for polymer-based room-temperature phosphorescence(RTP)materials,the limited efficiencies of persistent RTP still hinder their development.Herein,a simple and universal strategy of ...Despite great achievements obtained for polymer-based room-temperature phosphorescence(RTP)materials,the limited efficiencies of persistent RTP still hinder their development.Herein,a simple and universal strategy of using the dual-functional additive of Cs+was presented,which could simultaneously enhance the efficiency(Φp)and maintain the long lifetime(τp)of RTP in existing polymer-based systems with various phosphors and polymers.Among them,the commercial emitter(TpB)-doped polyvinyl alcohol(PVA)/Cs_(2)CO_(3) system possessed an extremely high Φp up to 75.5% and still maintained a longτp of 2.13 s,by introducing the heavy-atom effect and an extra network of ionic bonding through the Cs+additive.Additionally,the temperature resistance of RTP in TpB@PVA/Cs+film could also be improved to 85℃.More satisfactorily,the efficiency of Förster resonance energy transfer(FRET)from RTP to near-infrared(NIR)was also remarkably enhanced in the multi-component systems.This work provides a simple and universal strategy for developing polymer systems with high RTP performance.展开更多
The photophysical properties of a series of hydroxyl Corroles, Corrole-F, Corrole-Cl, Corrole-Br, Corrole-I and Corrole-2I, have been investigated by steady-state and time-resolved transient spectroscopy. The absorpti...The photophysical properties of a series of hydroxyl Corroles, Corrole-F, Corrole-Cl, Corrole-Br, Corrole-I and Corrole-2I, have been investigated by steady-state and time-resolved transient spectroscopy. The absorption spectra show a strong peak around 420 nm corresponding to B band and several weak Q absorption bands between 450 nm and 650 nm, exhibiting much stronger Q band absorption than that of porphyrin. The absorptions of these Corroles increase with the atom weight and the number of halogen atoms. All samples show similar fluorescence characteristics of an emission peak at 650 nm. The fluorescence intensities significantly decrease with the atom weight and the number of halogen atoms. The fluorescence quantum yield of Corrole-I is 0.947%, which is larger than that of Corrole-2I (0.381%). The fluorescence dynamics of the hydroxyl Corroles shows that both the fluorescence lifetime and the intersystem-crossing transition time of these Corroles decrease sharply with the increase of the atom weight and the number of halogen atoms, which may lead to the increase of the triplet state quantum yield. The heavy-atom effect on active oxygen of PDT has also been discussed by the end of this paper.展开更多
Developing pure organic room-temperature phosphorescence(RTP)materials remains an enormous challenge,especially for efficient near-infrared(NIR)RTP materials.Herein,a functional unit combination strategy is employed t...Developing pure organic room-temperature phosphorescence(RTP)materials remains an enormous challenge,especially for efficient near-infrared(NIR)RTP materials.Herein,a functional unit combination strategy is employed to design a series of pure organic molecules,in which benzo[c][1,2,5]thiadiazole(BZT)serves as the main luminescent core of RTP,while the folded units are responsible for spin-orbit coupling(SOC)enhancement and emission redshift.By integrating both rigid and flexible folded units into the BZT core,we observe the n/πorbital decoupling between the folded units and the BZT core.This orbital decoupling facilitates significant interplay between orbital angular momentum and heavy-atom effect,maximizing the SOC.As a result,a molecule functionalized with thianthrene and phenyl selenide demonstrates efficient NIR RTP emission,which exhibits a maximum RTP wavelength at 705 nm and a high RTP efficiency of 10.25%,surpassing most of the reported pure organic NIR RTP materials.As an emitter,its doped organic light-emitting diode(OLED)device demonstrates excellent NIR electroluminescence with a maximum external quantum efficiency of 1.21%.To our knowledge,this work not only reports the first example of pure organic NIR phosphorescent OLED,but also reveals a n/πorbital decoupling strategy for designing highly efficient pure organic RTP materials.展开更多
基金partially supported by the National Key R&D Program of China (No.2022YFE0199700)the National Natural Science Foundation of China (NSFC) projects (Nos.22077139and 22122705)CAMS Innovation Fund for Medical Sciences(CIFMS)(No.2022-I2M-2–002)。
文摘Photoacoustic agents combining photodynamic therapy(PDT) and photothermal therapy(PTT) functions have emerged as potent theranostic agents for combating cancer. The molecular approaches for enhancing the near-infrared(NIR)-absorption and maximizing non-radiative energy transfer are essential for effective photoacoustic imaging(PAI) and therapy applications. In addition, such molecules with high specificity and affinity to cancer cells are urgently needed, which would further decrease the side effect during treatments. In this study, we applied a heavy-atom engineering strategy and introduced p-aminophenol,-thio, and-seleno moieties into NIR heptamethine cyanine(Cy7) skeleton(Cy7-X-NH_(2), X = O, S, Se) to significantly increase photothermal conversion efficiency for PTT and promote intersystem crossing for PDT.Additionally, we designed a series of nitroreductase(NTR)-activated photoacoustic probes(Cy7-X-NO_(2),X = O, S, Se), and target hypoxic tumors with NTR overexpression. Our prostate cancer targeting probe,Cy7-Se-NO_(2)-KUE, exhibited specific tumor photoacoustic signals and effective tumor killing through outstanding synergistic PTT/PDT in vivo. These findings highlighted a versatile strategy for cancer photoacoustic diagnosis and enhanced phototherapy.
基金We would like to thank the National Natural Science Foundation of China(Grant Nos.51173096,21161160447 and 61177023)for financial support.
文摘To attain high efficiencies in hybrid white organic light-emitting diodes(WOLEDs),mutual quenching of the fluorophors and phosphors should be minimized.Efforts have been devoted to reducing the triplet quenching of phosphors;however,the quenching of fluorophors by the external heavy-atom effect(EHA)introduced by the phosphors is often ignored.Here,we observed that conventional fluorophors and fluorophors with thermally activated delayed fluorescence(TADF)behave differently in the presence of EHA perturbers.The efficiencies of the conventional fluorophors suffer greatly from the EHA,whereas the TADF fluorophors exhibit negligible changes,which makes TADF materials ideal fluorophors for hybrid devices.WOLEDs using a blue TADF fluorophor and an orange phosphor achieve a maximum forward viewing external quantum efficiency of 19.6%and a maximum forward viewing power efficiency of 50.2 lm W^(-1),among the best values for hybrid WOLEDs.This report is the first time that the EHA effect has been considered in hybrid WOLEDs and that a general strategy toward highly efficient hybrid WOLEDs with simple structures is proposed.
基金financially supported by Shanghai Municipal Science and Technology Major Project (No.2018SHZDZX03)National Natural Science Foundation of China (Nos.21788102,21572063)the Fundamental Research Funds for the Central Universities。
文摘The preparation of amorphous pure organic room-temperature phosphorescence materials with high efficiency is still a challenging task. Herein, we introduce a CB[6] derivative-based supramolecular selfassembling strategy. A water soluble and ellipsoidal deformed CB[6] derivative is used to self-assemble with 4-(4-bromophenyl)-1-methylpyridin-1-ium chloride, bromide and hexafluorophosphate in water. After freeze-drying, the obtained amorphous complexes exhibit brilliant green phosphorescence emission under ambient conditions, with phosphorescence efficiency up to 59%, 60% and 72%, respectively. This is the first report of amorphous non-polymeric pure organic room-temperature phosphorescence with such a high efficiency. In view of the dynamic self-assembling property, the complexes are responsive to water,which could enable information encryption.
基金supported by the National Natural Science Foundation of China(52222308 and 22135004)the National Key Research and Development Program(2023YFE0203300 and 2024YFB3612100)+2 种基金the Guangdong Basic and Applied Basic Research Foundation(2021B1515120041)the Open Project Program of Wuhan National Laboratory for Optoelectronics(2023WNLOKF010)the National Natural Science Foundation of China’s Youth Project for Doctoral Students(524B2035).
文摘While intramolecular cyclization effectively modulates photoelectronic properties of multi-resonance(MR)-thermally activated delayed fluorescence(TADF)emitters,simultaneous narrowing full width at half maxima(FWHM)of spectra and accelerating reverse intersystem crossing(RISC)remain a formidable challenge.Here,we introduce a phosphorus-carbon-bridged cyclization in MR skeletons to synergistically suppress high-frequency molecular vibrations via skeleton rigidification and enhance spin-orbital coupling through introducing heavy-atom effects.Implementing this approach,two blue emitters,phenylphosphine oxide-bridged(BCzBN-PO)and phenylphosphine sulfide-bridged(BCzBN-PS),are developed and exhibit emission peaks at 467 and 474 nm with FWHMs of 19 and 18 nm,respectively.Moreover,benefiting from the additional heavy atom effect of sulfur complementing that of phosphorus,BCzBN-PS achieved a kRISC of 8.5×10^(5)s^(−1),nearly 8-fold higher than that of BCzBN-PO(1.1×10^(5)s^(−1)).In the non-sensitized device architecture,both emitters exhibited narrowband emission with a FWHM<30 nm and a maximum external quantum efficiency(EQE)>20%.Notably,BCzBN-PS,leveraging its higher upconversion rate,demonstrated a superior maximum EQE and lower efficiency roll-off.Furthermore,in the TADF-sensitized device configuration,the organic light-emitting diodes further validated the enhanced upconversion efficiency—evidenced by BCzBN-PS delivering a higher maximum EQE than BCzBN-PO(43.0%vs.41.2%)and a reduced efficiency roll-off(30.1%vs.25.9%at 1000 cd m−2).This work establishes a molecular engineering paradigm that balances color purity and exciton utilization efficiency,paving new avenues for high-performance narrowband electroluminescence.
基金supported by the National Natural Science Foundation of China(52073315,52373199,and 22375222)Natural Science Foundation of Guangdong(2023A1515012679 and 2023A1515011308)+1 种基金Guangdong Provincial Department of Science and Technology(2021B1212050005 and 2021A1515110453)Fundamental Research Funds for the Central Universities,Sun Yat-sen University(23yxqntd002).
文摘Despite great achievements obtained for polymer-based room-temperature phosphorescence(RTP)materials,the limited efficiencies of persistent RTP still hinder their development.Herein,a simple and universal strategy of using the dual-functional additive of Cs+was presented,which could simultaneously enhance the efficiency(Φp)and maintain the long lifetime(τp)of RTP in existing polymer-based systems with various phosphors and polymers.Among them,the commercial emitter(TpB)-doped polyvinyl alcohol(PVA)/Cs_(2)CO_(3) system possessed an extremely high Φp up to 75.5% and still maintained a longτp of 2.13 s,by introducing the heavy-atom effect and an extra network of ionic bonding through the Cs+additive.Additionally,the temperature resistance of RTP in TpB@PVA/Cs+film could also be improved to 85℃.More satisfactorily,the efficiency of Förster resonance energy transfer(FRET)from RTP to near-infrared(NIR)was also remarkably enhanced in the multi-component systems.This work provides a simple and universal strategy for developing polymer systems with high RTP performance.
基金supported by the Open Fund of the State Key Laboratory of Optoelectronic Materials and Technologies (Sun Yat-sen Unversity)the Science Fundation of Guangdong (Grant No. 9351027501000003)
文摘The photophysical properties of a series of hydroxyl Corroles, Corrole-F, Corrole-Cl, Corrole-Br, Corrole-I and Corrole-2I, have been investigated by steady-state and time-resolved transient spectroscopy. The absorption spectra show a strong peak around 420 nm corresponding to B band and several weak Q absorption bands between 450 nm and 650 nm, exhibiting much stronger Q band absorption than that of porphyrin. The absorptions of these Corroles increase with the atom weight and the number of halogen atoms. All samples show similar fluorescence characteristics of an emission peak at 650 nm. The fluorescence intensities significantly decrease with the atom weight and the number of halogen atoms. The fluorescence quantum yield of Corrole-I is 0.947%, which is larger than that of Corrole-2I (0.381%). The fluorescence dynamics of the hydroxyl Corroles shows that both the fluorescence lifetime and the intersystem-crossing transition time of these Corroles decrease sharply with the increase of the atom weight and the number of halogen atoms, which may lead to the increase of the triplet state quantum yield. The heavy-atom effect on active oxygen of PDT has also been discussed by the end of this paper.
基金supported by the National Natural Science Foundation of China(grant nos.52373183,52103209,52073117,and 52273179)the National Key Research and Development Program of China(grant no.2020YFA0714603).
文摘Developing pure organic room-temperature phosphorescence(RTP)materials remains an enormous challenge,especially for efficient near-infrared(NIR)RTP materials.Herein,a functional unit combination strategy is employed to design a series of pure organic molecules,in which benzo[c][1,2,5]thiadiazole(BZT)serves as the main luminescent core of RTP,while the folded units are responsible for spin-orbit coupling(SOC)enhancement and emission redshift.By integrating both rigid and flexible folded units into the BZT core,we observe the n/πorbital decoupling between the folded units and the BZT core.This orbital decoupling facilitates significant interplay between orbital angular momentum and heavy-atom effect,maximizing the SOC.As a result,a molecule functionalized with thianthrene and phenyl selenide demonstrates efficient NIR RTP emission,which exhibits a maximum RTP wavelength at 705 nm and a high RTP efficiency of 10.25%,surpassing most of the reported pure organic NIR RTP materials.As an emitter,its doped organic light-emitting diode(OLED)device demonstrates excellent NIR electroluminescence with a maximum external quantum efficiency of 1.21%.To our knowledge,this work not only reports the first example of pure organic NIR phosphorescent OLED,but also reveals a n/πorbital decoupling strategy for designing highly efficient pure organic RTP materials.
