Two piezochromic fluorescent compounds are prepared by introducing thiomethyl substituents to the peripheralpositions of two related cyano oligo(p-phenylene vinylenes) (CN-OPV). The new derivatives, namely, 1,4-bis[2-...Two piezochromic fluorescent compounds are prepared by introducing thiomethyl substituents to the peripheralpositions of two related cyano oligo(p-phenylene vinylenes) (CN-OPV). The new derivatives, namely, 1,4-bis[2-cyano-2(4-thiomethylphenyl)ethenyl]benzene (TOPV1) and 1,4-bis(1-cyano-2-(4-thiomethylphenyl)ethenyl) benzene (TOPV2), are characterized by NMR, powder X-ray diffraction data (XRD) and differential scanning calorimetric (DSC) data. UV-Vis and fluorescence spectra are also measured. TOPV1 with the cyano groups farther away from the central aromatic ring is photoluminescent, and on application of pressure exhibits a more obvious color change and higher Stokes shift than those measured for TOPV2. We also observe piezochromic aggregation-induced emission (PAIE) for TOPV2, but TOPV1 does not exhibit any PAIE.展开更多
Comprehensive Summary Currently,solid-state fluorescent carbonized polymer dots(CPDs)have attracted attention increasingly due to their applications for optoelectronic display.However,designing CPDs possessing solid-s...Comprehensive Summary Currently,solid-state fluorescent carbonized polymer dots(CPDs)have attracted attention increasingly due to their applications for optoelectronic display.However,designing CPDs possessing solid-state fluorescence and clarifying the fluorescence mechanism remain challenging.Herein,we initially synthesized a novel type of polythiophene derivatives CPDs,poly-4,4’-(thiophene-3,4-diyl)dibenzoic acid carbonized polymer dots(PDBA-CPDs)with solid-state fluorescence.Subsequently,the structural and optical characterization revealed that the solid-state fluorescence originated from the aggregation induced emission of the CPDs.In brief,in aggregation state,the remaining polymer structure groups on the surface of the CPDs overlapped and weakened the non-radiative transition,enhancing solid-state fluorescence emission.Thirdly,three polythiophene-derived CPDs were designed to further demonstrate the aggregation induced solid-state fluorescence mechanism.Finally,owing to their unique properties of solid-state fluorescence,the white LEDs(light emitting diodes)were fabricated with high color rendering index(CRI)of 82.7 and CIE coordinates of(0.37,0.39)using commercial 460 nm chip.展开更多
Rodents are popular biological models for physiological and behavioral research in neuroscience and rats are better models than mice due to their higher genome similarity to human and more accessible surgical procedur...Rodents are popular biological models for physiological and behavioral research in neuroscience and rats are better models than mice due to their higher genome similarity to human and more accessible surgical procedures.However,rat brain is larger than mice brain and it needs powerful imaging tools to implement better penetration against the scattering of the thicker brain tissue.Three-photon fluorescence microscopy(3PFM)combined with near-infrared(NIR)excitation has great potentials for brain circuits imaging beause of its abilities of anti scattering,deep-tissue imaging,and high signal-to-noise ratio(SNR).In this work,a type of AIE lumninogen with red fuorescence was synthesized and encapsulated with Pluronic F-127 to make up form nano-particles(NPs).Bright DCDPP-2TPA NPs were employed for in trino three-photon fuorescent laser scanning microscopy of blood vessels in rats brain under 1550 nm femtosecond laser exci-tation.A fine three-dimensional(3D)reconstruction up to the deepness of 600 pm was achieved and the blood flow velocity of a selected vessel was measured in vrito as well.Our 3PFM deep brain imaging method simultaneously recorded the morphology and function of the brain blood vessels in vivo in the rat model.Using this angiography combined with the arsenal of rodent's brain disease,models can accelerate the neuroscience research and clinical diagnosis of brain disease in the future.展开更多
Fluorescent probes play a key role in modern biomedical research.As compared to inorganic quantum dots(QDs)composed with heavy metal elements,organic dye-based fluorescent nanoparticles have higher biocompatibility an...Fluorescent probes play a key role in modern biomedical research.As compared to inorganic quantum dots(QDs)composed with heavy metal elements,organic dye-based fluorescent nanoparticles have higher biocompatibility and are richer in variety.However,traditional organic fluorophores tend to quench fluorescence upon aggregation,which is known as aggregation-caused quenching(ACQ)effect that hinders the fabrication of highly emissive fluorescent nanoparticles.In this work,we demonstrate the synthesis of organic fluorescent dots with aggregation-induced emission(AIE)in far-red/near-infrared(FA/NIR)region.A conventional ACQ-characteristic fluorescent dye,3,4:9,10-tetracarboxylic perylene bisimide(PBI),is converted into an AIE fluorogen through attaching two tetraphenylethylene(TPE)moieties.The fluorescent dots with surface folic acid groups are fabricated from PBI derivative(DTPEPBI),showing specific targeting effect to folate receptor-overexpressed cancer cells.In vivo studies also suggest that the folic acid-functionalized AIE dots preferentially accumulate in the tumor site through enhanced permeability and retention(EPR)effect and folate receptor-mediated active targeting effect.The low cytotoxicity,good FR/NIR contrast and excellent targeting ability in in vitro/in vivo imaging indicate that the AIE dots have great potentials in advanced bioimaging applications.展开更多
Nowadays, purely organic materials with delayed fluorescence （DF） are being enthusiastically developed and extensively utilized as light-emitting materials to fabricate OLEDs because of their high exciton utilizatio...Nowadays, purely organic materials with delayed fluorescence （DF） are being enthusiastically developed and extensively utilized as light-emitting materials to fabricate OLEDs because of their high exciton utilization and metal-flee nature. These DF materials usually have a small single-triplet splitting （AEsT）, and the nonradiative triplet excitons （75%） can be converted into radiative singlet excitons via thermally promoted reverse intersystem crossing （RISC） processes,展开更多
Influence of intramolecular π-π interaction on the luminescent properties of thermally activated delayed fluorescence（TADF） molecule（3, 5-bis（3,6-di-tert-butyl-9 H-carbazol-9-yl）-phenyl）（pyridin-4-yl） methan...Influence of intramolecular π-π interaction on the luminescent properties of thermally activated delayed fluorescence（TADF） molecule（3, 5-bis（3,6-di-tert-butyl-9 H-carbazol-9-yl）-phenyl）（pyridin-4-yl） methanone（DTCBPY） is theoretically studied by using the density functional theory（DFT） and time-dependent density functional theory（TD-DFT）.Four conformations（named as A, B, C, and D） of the DTCBPY can be found by relax scanning, and the configuration C corresponds to the luminescent molecule detected experimentally. Besides, we calculate the proportion of each conformation by Boltzmann distribution, high configuration ratios（44% and 52%） can be found for C and D. Moreover, C and D are found to exist with an intramolecular π-π interaction between one donor and the acceptor; the intramolecular interaction brings a smaller Huang-Rhys factor and reduced reorganization energy. Our work presents a rational explanation for the experimental results and demonstrates the importance of the intramolecular π-π interaction to the photophysical properties of TADF molecules.展开更多
Thermoresponsive fluorescent polymers(TFPs) with unique temperature-dependent luminescent properties are of great importance for the development of new functional devices in recent years. Herein, we facilely synthesiz...Thermoresponsive fluorescent polymers(TFPs) with unique temperature-dependent luminescent properties are of great importance for the development of new functional devices in recent years. Herein, we facilely synthesized an efficient blue-emissive polymer, abbreviated as PCB-TPE, using tetraphenylethene(TPE) as the main building block. PCB-TPE is thermally stable with a novel property of aggregation induced emission(AIE). The thermoresponsive property and mechanism of PCB-TPE were investigated. Its emission shows temperature-dependent features and reveals fine details in the thermal transitions from-10 °C to 60 °C. The polymer offers a platform for the development of efficient luminescent materials for further biological and optoelectronic applications.展开更多
Based on the combination of B21C7/dialkylammonium salt host-guest interactions and tetraphenylethylene （TPE）-based aggregation-induced emission （AIE） effect, a fluorescent supramolecular crosslinked polymer gel wa...Based on the combination of B21C7/dialkylammonium salt host-guest interactions and tetraphenylethylene （TPE）-based aggregation-induced emission （AIE） effect, a fluorescent supramolecular crosslinked polymer gel was successfully prepared. Compared with the solution of TPE-containing small molecules, this gel exhibited remarkable fluorescence enhancement due to the AIE effect of TPE units. The ＂gelation induced fluorescence emission＂ phenomenon can be explained by the hindered intramolecular rotation of phenyl rings of TPE. Because of the reversibility and stimuli-responsiveness of the B21C7/dialkylammonium salt host-guest interactions, the transition between the fluorescent supramolecular crosslinked polymer gel and the disassembled sol with very weak fluorescence can be realized by adding pH and thermal stimuli. This novel material contributes to the development of supramolecular chemistry, polymer science and fluorescent materials and offers a new method to construct functional supramolecular materials.展开更多
A gold（I） complex that exhibited aggregation-induced emission in acetonitrile-water mixtures was designed. It showed high selectivity and sensitivity for Hg2＋ in acetonitrile-H20 （1 ：1, V ： V） solution. Dynamic...A gold（I） complex that exhibited aggregation-induced emission in acetonitrile-water mixtures was designed. It showed high selectivity and sensitivity for Hg2＋ in acetonitrile-H20 （1 ：1, V ： V） solution. Dynamic light scatter-ing measurements were conducted to verify that the addition of Hg2 changed the particle size and induced fluorescence quenching.展开更多
A cyano-substituted diarylethlene derivative aggregation-induced emission （ALE） dye with two amino end-groups and 4,4＇-（hexafluoroisopropylidene）diphthalic anhydride were facilely incorporated into red fluorescen...A cyano-substituted diarylethlene derivative aggregation-induced emission （ALE） dye with two amino end-groups and 4,4＇-（hexafluoroisopropylidene）diphthalic anhydride were facilely incorporated into red fluorescent organic nanoparticles （FONs） via room temperature anhydride ring-opening polymerization under an air atmosphere. These obtained RO-HFDA FONs were characterized by a series of techniques including gel permeation chromatography, Fourier transform infrared spectroscopy, size distribution and zeta potential measurements, UV-Vis absorption spectrum, fluorescent spectroscopy and transmission electron microscopy. Biocompatibility evaluation and cell uptake behavior of RO-HFDA FONs were further investigated to explore their potential biomedical application. We demonstrated that such FONs showed high water dispersibility, stable uniform spherical morphology （150-200 nm）, broad excitation band （350-605 nm）, intense red fluorescence （627 nm） and excellent biocompatibility, making them promising for cell imaging applications.展开更多
文摘Two piezochromic fluorescent compounds are prepared by introducing thiomethyl substituents to the peripheralpositions of two related cyano oligo(p-phenylene vinylenes) (CN-OPV). The new derivatives, namely, 1,4-bis[2-cyano-2(4-thiomethylphenyl)ethenyl]benzene (TOPV1) and 1,4-bis(1-cyano-2-(4-thiomethylphenyl)ethenyl) benzene (TOPV2), are characterized by NMR, powder X-ray diffraction data (XRD) and differential scanning calorimetric (DSC) data. UV-Vis and fluorescence spectra are also measured. TOPV1 with the cyano groups farther away from the central aromatic ring is photoluminescent, and on application of pressure exhibits a more obvious color change and higher Stokes shift than those measured for TOPV2. We also observe piezochromic aggregation-induced emission (PAIE) for TOPV2, but TOPV1 does not exhibit any PAIE.
基金the National Natural Science Foundation of China(Grant Nos.52272052,51972315,21873110,and 61720106014).
文摘Comprehensive Summary Currently,solid-state fluorescent carbonized polymer dots(CPDs)have attracted attention increasingly due to their applications for optoelectronic display.However,designing CPDs possessing solid-state fluorescence and clarifying the fluorescence mechanism remain challenging.Herein,we initially synthesized a novel type of polythiophene derivatives CPDs,poly-4,4’-(thiophene-3,4-diyl)dibenzoic acid carbonized polymer dots(PDBA-CPDs)with solid-state fluorescence.Subsequently,the structural and optical characterization revealed that the solid-state fluorescence originated from the aggregation induced emission of the CPDs.In brief,in aggregation state,the remaining polymer structure groups on the surface of the CPDs overlapped and weakened the non-radiative transition,enhancing solid-state fluorescence emission.Thirdly,three polythiophene-derived CPDs were designed to further demonstrate the aggregation induced solid-state fluorescence mechanism.Finally,owing to their unique properties of solid-state fluorescence,the white LEDs(light emitting diodes)were fabricated with high color rendering index(CRI)of 82.7 and CIE coordinates of(0.37,0.39)using commercial 460 nm chip.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(LR17F050001 and LY17C090005)the National Natural Science Foundation of China(61735016 and 91632105)National Basic Research Program of China(973 Program,2013CB834701 and 2013CB834704).
文摘Rodents are popular biological models for physiological and behavioral research in neuroscience and rats are better models than mice due to their higher genome similarity to human and more accessible surgical procedures.However,rat brain is larger than mice brain and it needs powerful imaging tools to implement better penetration against the scattering of the thicker brain tissue.Three-photon fluorescence microscopy(3PFM)combined with near-infrared(NIR)excitation has great potentials for brain circuits imaging beause of its abilities of anti scattering,deep-tissue imaging,and high signal-to-noise ratio(SNR).In this work,a type of AIE lumninogen with red fuorescence was synthesized and encapsulated with Pluronic F-127 to make up form nano-particles(NPs).Bright DCDPP-2TPA NPs were employed for in trino three-photon fuorescent laser scanning microscopy of blood vessels in rats brain under 1550 nm femtosecond laser exci-tation.A fine three-dimensional(3D)reconstruction up to the deepness of 600 pm was achieved and the blood flow velocity of a selected vessel was measured in vrito as well.Our 3PFM deep brain imaging method simultaneously recorded the morphology and function of the brain blood vessels in vivo in the rat model.Using this angiography combined with the arsenal of rodent's brain disease,models can accelerate the neuroscience research and clinical diagnosis of brain disease in the future.
文摘Fluorescent probes play a key role in modern biomedical research.As compared to inorganic quantum dots(QDs)composed with heavy metal elements,organic dye-based fluorescent nanoparticles have higher biocompatibility and are richer in variety.However,traditional organic fluorophores tend to quench fluorescence upon aggregation,which is known as aggregation-caused quenching(ACQ)effect that hinders the fabrication of highly emissive fluorescent nanoparticles.In this work,we demonstrate the synthesis of organic fluorescent dots with aggregation-induced emission(AIE)in far-red/near-infrared(FA/NIR)region.A conventional ACQ-characteristic fluorescent dye,3,4:9,10-tetracarboxylic perylene bisimide(PBI),is converted into an AIE fluorogen through attaching two tetraphenylethylene(TPE)moieties.The fluorescent dots with surface folic acid groups are fabricated from PBI derivative(DTPEPBI),showing specific targeting effect to folate receptor-overexpressed cancer cells.In vivo studies also suggest that the folic acid-functionalized AIE dots preferentially accumulate in the tumor site through enhanced permeability and retention(EPR)effect and folate receptor-mediated active targeting effect.The low cytotoxicity,good FR/NIR contrast and excellent targeting ability in in vitro/in vivo imaging indicate that the AIE dots have great potentials in advanced bioimaging applications.
文摘Nowadays, purely organic materials with delayed fluorescence （DF） are being enthusiastically developed and extensively utilized as light-emitting materials to fabricate OLEDs because of their high exciton utilization and metal-flee nature. These DF materials usually have a small single-triplet splitting （AEsT）, and the nonradiative triplet excitons （75%） can be converted into radiative singlet excitons via thermally promoted reverse intersystem crossing （RISC） processes,
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11374195 and 21403133)Taishan Scholar Project of Shandong Normal University,China+1 种基金the Promotive Research Fund for Excellent Young and Middle-aged Scientists of Shandong Province,China(Grant No.BS2014cl001)the China Postdoctoral Science Foundation(Grant No.2014M560571)
文摘Influence of intramolecular π-π interaction on the luminescent properties of thermally activated delayed fluorescence（TADF） molecule（3, 5-bis（3,6-di-tert-butyl-9 H-carbazol-9-yl）-phenyl）（pyridin-4-yl） methanone（DTCBPY） is theoretically studied by using the density functional theory（DFT） and time-dependent density functional theory（TD-DFT）.Four conformations（named as A, B, C, and D） of the DTCBPY can be found by relax scanning, and the configuration C corresponds to the luminescent molecule detected experimentally. Besides, we calculate the proportion of each conformation by Boltzmann distribution, high configuration ratios（44% and 52%） can be found for C and D. Moreover, C and D are found to exist with an intramolecular π-π interaction between one donor and the acceptor; the intramolecular interaction brings a smaller Huang-Rhys factor and reduced reorganization energy. Our work presents a rational explanation for the experimental results and demonstrates the importance of the intramolecular π-π interaction to the photophysical properties of TADF molecules.
基金financially supported by the National Natural Science Foundation of China (No. 21374136)the Fundamental Research Funds for the Central Universities (Nos. 17lgjc03 and 18lgpy04)the Opening Project of the Key Laboratory of Polymer Processing Engineering (South China University of Technology, Ministry of Education, No. KFKT1703)
文摘Thermoresponsive fluorescent polymers(TFPs) with unique temperature-dependent luminescent properties are of great importance for the development of new functional devices in recent years. Herein, we facilely synthesized an efficient blue-emissive polymer, abbreviated as PCB-TPE, using tetraphenylethene(TPE) as the main building block. PCB-TPE is thermally stable with a novel property of aggregation induced emission(AIE). The thermoresponsive property and mechanism of PCB-TPE were investigated. Its emission shows temperature-dependent features and reveals fine details in the thermal transitions from-10 °C to 60 °C. The polymer offers a platform for the development of efficient luminescent materials for further biological and optoelectronic applications.
文摘Based on the combination of B21C7/dialkylammonium salt host-guest interactions and tetraphenylethylene （TPE）-based aggregation-induced emission （AIE） effect, a fluorescent supramolecular crosslinked polymer gel was successfully prepared. Compared with the solution of TPE-containing small molecules, this gel exhibited remarkable fluorescence enhancement due to the AIE effect of TPE units. The ＂gelation induced fluorescence emission＂ phenomenon can be explained by the hindered intramolecular rotation of phenyl rings of TPE. Because of the reversibility and stimuli-responsiveness of the B21C7/dialkylammonium salt host-guest interactions, the transition between the fluorescent supramolecular crosslinked polymer gel and the disassembled sol with very weak fluorescence can be realized by adding pH and thermal stimuli. This novel material contributes to the development of supramolecular chemistry, polymer science and fluorescent materials and offers a new method to construct functional supramolecular materials.
基金This work was supported by the National Natural Science Foundation of China （Nos. 20931006, 21072070 and 21272088） and the Program for Academic Leader in Wuhan Municipality （No. 201271130441）.
文摘A gold（I） complex that exhibited aggregation-induced emission in acetonitrile-water mixtures was designed. It showed high selectivity and sensitivity for Hg2＋ in acetonitrile-H20 （1 ：1, V ： V） solution. Dynamic light scatter-ing measurements were conducted to verify that the addition of Hg2 changed the particle size and induced fluorescence quenching.
基金financially supported by the National Natural Science Foundation of China(Nos.21134004,21201108 and 51363016)the National 973 Project(No.2011CB935700)China Postdoctoral Science Foundation(Nos.2012M520243,2013T60100)
文摘A cyano-substituted diarylethlene derivative aggregation-induced emission （ALE） dye with two amino end-groups and 4,4＇-（hexafluoroisopropylidene）diphthalic anhydride were facilely incorporated into red fluorescent organic nanoparticles （FONs） via room temperature anhydride ring-opening polymerization under an air atmosphere. These obtained RO-HFDA FONs were characterized by a series of techniques including gel permeation chromatography, Fourier transform infrared spectroscopy, size distribution and zeta potential measurements, UV-Vis absorption spectrum, fluorescent spectroscopy and transmission electron microscopy. Biocompatibility evaluation and cell uptake behavior of RO-HFDA FONs were further investigated to explore their potential biomedical application. We demonstrated that such FONs showed high water dispersibility, stable uniform spherical morphology （150-200 nm）, broad excitation band （350-605 nm）, intense red fluorescence （627 nm） and excellent biocompatibility, making them promising for cell imaging applications.
