Metal-organic frameworks(MOFs),which are self-assembled porous coordination materials,have garnered considerable attention in the fields of optoelectronics,photovoltaic,photochemistry,and photocatalysis due to their d...Metal-organic frameworks(MOFs),which are self-assembled porous coordination materials,have garnered considerable attention in the fields of optoelectronics,photovoltaic,photochemistry,and photocatalysis due to their diverse structures and excellent tunability.However,the performance of MOF-based optoelectronic applications currently falls short of the industry benchmark.To enhance the performance of MOF materials,it is imperative to undertake comprehensive investigations aimed at gaining a deeper understanding of photophysics and sequentially optimizing properties related to photocarrier transport,recombination,interaction,and transfer.By utilizing femtosecond laser pulses to excite MOFs,time-resolved optical spectroscopy offers a means to observe and characterize these ultrafast microscopic processes.This approach adds the time coordinate as a novel dimension for comprehending the interaction between light and MOFs.Accordingly,this review provides a comprehensive overview of the recent advancements in the photophysics of MOFs and additionally outlines potential avenues for exploring the time domain in the investigation of MOFs.展开更多
A series of new silicon-containing poly（p-arylene vinylene）s （PAVs） with anthracene units in the main chain were synthesized by hydrosilylation reaction. The introduction of organosilicon units improved the solubi...A series of new silicon-containing poly（p-arylene vinylene）s （PAVs） with anthracene units in the main chain were synthesized by hydrosilylation reaction. The introduction of organosilicon units improved the solubility of the polymers, and the π-π conjugation of polymeric chains was interrupted. These polymers behaved as blue-green light emitters with their fluorescence maximum at 447-499 nm and quantum yields in the range of 0.28-0.30 in solution.展开更多
Hypocrellins are novel photosensitizers from China, which are demonstrated to have significant anti-tumor and anti-virus activity and to be potential photo-dynamic therapy (PDT) agents. As compared with hemato-porphyr...Hypocrellins are novel photosensitizers from China, which are demonstrated to have significant anti-tumor and anti-virus activity and to be potential photo-dynamic therapy (PDT) agents. As compared with hemato-porphyrin, the only approved photosensitizer, hypocrellins have several advantages, such as easy preparation and easy purification, high triplet quantum yield, high singlet-oxygen quantum yield, high phototoxicity but low dark toxicity, and rapid clearance from normal issues. This article reviews briefly the photophysics, photochemistry and photobiology of hypocrellins on the basis of the domestic and international research results.展开更多
Understanding the structure-property relationships in polycyclic conjugated hydrocarbons(PCHs)is crucial in controlling their electronic properties and developing new optically functional materials.Aromaticity is a fu...Understanding the structure-property relationships in polycyclic conjugated hydrocarbons(PCHs)is crucial in controlling their electronic properties and developing new optically functional materials.Aromaticity is a fundamentally important and intriguing property of numerous organic chemical structures and has stimulated a myriad of experimental and theoretical investigations.Exploiting aromaticity rules for the rational design of optoelectronic materials with the desired photophysical characteristics is a challenging yet fascinating task.Herein we present an in-depth computational and spectroscopic study on the structure-property relationships of dinaphthopentalenes(DNPs).Results highlight that the different fusion patterns between 4nπand 4n+2πunits endow these PCHs with the tunable aromaticity in the ground state/excited state,which leads to the diverse electronic structures and consequently the distinctive excited state photophysics.Accordingly,we propose a combined aromaticity design strategy for rationally modulating and tailoring electronic and optical properties of PCH skeletons.These outcomes not only present a full picture of the excited state dynamics of the DNP system and afford a new class of efficient singlet fission-active materials but also provide some basic guidelines for exploiting aromaticity rules to design and develop new optical function materials.展开更多
A series of poly（p-phenylenevinylene）s （PPVs） with good solubility were synthesized from thermal elimination of precursor poly（2,5-didodecyloxy-p-phenylenevinylene） at different temperature via Wessling method. ...A series of poly（p-phenylenevinylene）s （PPVs） with good solubility were synthesized from thermal elimination of precursor poly（2,5-didodecyloxy-p-phenylenevinylene） at different temperature via Wessling method. The polymer photophysics were influenced by the thermal elimination condition, which was consistent with NMR and IR characterizations. The additional absorption peak at longer wavelength and the red-shifted emission maximum both in solution and in film, for PPVs obtained at high elimination temperature, indicated the existence of longer conjugated blocks in these systems. The emission maximum for drop-cast film （436 nm） for PPV obtained under 200 ℃ （PPV200） was 16 nm blue shifted to the spin-coated films （452 nm） or 29 nm to the solution （465 nm）. The SEM study showed drop-cast film had the morphology of isolated conjugated particles in the matrix while blurry linear structure was found for spin-coated film, which was consistent with the photophysics. The discussion about this difference was carried out based on the consideration of the flexibility of the polymer chains and different conjugated length of PPV in different states.展开更多
The fluorescence spectra of N--salicylidene-p-(N,N--dimethylamino)aniline have beeninvestigated in various solvents. Three kinds of fluorescence have been found in the solutionsof various concentrations. They are the ...The fluorescence spectra of N--salicylidene-p-(N,N--dimethylamino)aniline have beeninvestigated in various solvents. Three kinds of fluorescence have been found in the solutionsof various concentrations. They are the excited intermediate (EI) which is formed when theproton transfer has occurred but essentially retains the geometry of the enol tautomer, theexciplex (EX) which consists of a ground monomer and an excited state intermediate and theexcited dimer (ED) which is caused by ground state aggregate. The fluorescence lifetimesof the fluorophores have been measured in tetrahydrofuran (THF). Luminescent mechanismhas been discussed based on the fluorescence spectra and the kinetic data of the compound.展开更多
9-Fluorenylidenemalononitrile (FDCN) or 1,1 diphenyl 2,2 dicyanoethylene (DPCN) reacted with 10 methyl 9,10 dihydroacridine (AcrH 2) under irradiation ( λ >320 nm) to give couping products. In order t...9-Fluorenylidenemalononitrile (FDCN) or 1,1 diphenyl 2,2 dicyanoethylene (DPCN) reacted with 10 methyl 9,10 dihydroacridine (AcrH 2) under irradiation ( λ >320 nm) to give couping products. In order to gain further insight into the mechanism of the photo induced reaction, the photophysics of the reactions of FDCN or DPCN with AcrH 2 have been investigated by using UV vis spectroscopy, fluorescence spectroscopy, excitation spectroscopy and time resolved fluorescence spectroscopy, respectively. The results show that FDCN or DPCN interacts with AcrH 2 in the ground states to form a charge transfer complex, which further reacts to give the coupling product upon irradiation.展开更多
Azulene-fused acenes demonstrate enhanced stability,unique aromaticity,and distinctive photophysical properties,rendering them significant in organic electronics.In the present study,we report a new type of nonalterna...Azulene-fused acenes demonstrate enhanced stability,unique aromaticity,and distinctive photophysical properties,rendering them significant in organic electronics.In the present study,we report a new type of nonalternant analogue of pentacene incorporating a non-terminal azulene unit.Aromaticity analyses reveal that the five-membered rings in this analogue exhibit antiaromatic.The extensive conjugated aryl substituents on the acene’s side shift the HOMO distributions from the naphthyl ring and metallacycle to the aryl groups,thereby narrowing the HOMO-LUMO energy gap and enhancing absorptions in the low-energy regions.Furthermore,these fused acenes readily react with base rather than acid,resulting in reversible base/acid stimuli responsiveness.展开更多
Green-emitting iridium(Ⅲ)complexes were synthesised using chlorobridged dimer(ppy)_(2)Ir_(2)Cl_(2)(ppy)_(2),3-hydroxy-2-methyl-γ-pyranone,2-ethyl-3-hydroxy-4-pyranone,and 5-hydroxy-2-(hydroxymethyl)-1,4-pyranone as ...Green-emitting iridium(Ⅲ)complexes were synthesised using chlorobridged dimer(ppy)_(2)Ir_(2)Cl_(2)(ppy)_(2),3-hydroxy-2-methyl-γ-pyranone,2-ethyl-3-hydroxy-4-pyranone,and 5-hydroxy-2-(hydroxymethyl)-1,4-pyranone as the auxiliary ligand.The structure of the target product was characterised by nuclear magnetic resonance spectroscopy(~1H-NMR),infrared spectroscopy(IR)and mass spectrometry(MS),and its thermal stability,photophysical properties and electrochemical properties were investigated.The results show that the decomposition temperatures of Ir1,Ir2 and Ir3 are 349,292 and 200℃,respectively.The maximum emission wavelength of Ir1,Ir2 and Ir3 dissolved in dichloromethane is 491 nm.The HOMO energy level of Ir1,Ir2 and Ir3 are 5.39,-5.38,and-5.30 eV.The LUMO energy levels are-2.86,-2.85,and-2.80 eV,respectively.展开更多
The quenching processes of the excited singlet state of pyrene by triphenylamine,diphenyl- amine and N,N-dibenzylaniline in various solvents at room and lower temperature have been stu- died with both static state flu...The quenching processes of the excited singlet state of pyrene by triphenylamine,diphenyl- amine and N,N-dibenzylaniline in various solvents at room and lower temperature have been stu- died with both static state fluorescence spectroscopy and fluorescence lifetime techniques.On the basis of experimental data,a preliminary quenching mechanism has been discussed.The geome- trical configuration models of the exciplexes formed between the excited pyrene and aromatic ami- nes in nonpolar solvents were proposed.展开更多
Quinoidalπ-conjugated structures,a kind of fundamental subunits for organicπ-systems,may produce some intriguing optical,electronic and magnetic properties of polycyclic hydrocarbons(PHs).Herein,we report two thieno...Quinoidalπ-conjugated structures,a kind of fundamental subunits for organicπ-systems,may produce some intriguing optical,electronic and magnetic properties of polycyclic hydrocarbons(PHs).Herein,we report two thienothiophene-centered ladder-type polycyclic molecules(1 and 2),which possess one quinoidal thienothiophene moiety and two para-quinodimethane(p-QDM)subunits,respectively.As theoretically and experimentally studied,while 1 is a fully closed-shell molecule,2 owns an open-shell structure along with partial contribution of tetraradical state that is induced by the resonance of p-QDM.Moreover,although 2 has a largerπ-conjugated skeleton and open-shell electronic state,it exhibits larger bandgap and blue-shifted absorption.On the other hand,the reversible oxidation activity of 1 enables the preparation of its dication 1^(2+),and the studies on its single-crystal and aromatic structures demonstrate that its two positive charges are delocalized onto the oxygen atoms,thus achieving fullyπ-extended structure and near-infrared absorption.This study not only gains insight into quinoidalπ-subunits,but also provides an important basis for the development of antiaromatic and open-shellπ-electron materials.展开更多
Molecular engineering is a crucial strategy for improving the photovoltaic performance of dye-sensitized solar cells(DSSCs). Despite the common use of the donor-π bridge-acceptor architecture in designing sensitizers...Molecular engineering is a crucial strategy for improving the photovoltaic performance of dye-sensitized solar cells(DSSCs). Despite the common use of the donor-π bridge-acceptor architecture in designing sensitizers, the underlying structure-performance relationship remains not fully understood. In this study, we synthesized and characterized three sensitizers: MOTP-Pyc, MOS_(2)P-Pyc, and MOTS_(2)P-Pyc, all featuring a bipyrimidine acceptor. Absorption spectra, cyclic voltammetry, and transient photoluminescence spectra reveal a photo-induced electron transfer(PET) process in the excited sensitizers. Electron spin resonance spectroscopy confirmed the presence of charge-separated states. The varying donor and π-bridge structures among the three sensitizers led to differences in their conjugation effect, influencing light absorption abilities and PET processes and ultimately impacting the photovoltaic performance. Among the synthesized sensitizers, MOTP-Pyc demonstrated a DSSC efficiency of 3.04%. Introducing an additional thienothiophene block into the π-bridge improved the DSSC efficiency to 4.47% for MOTS_(2)P-Pyc. Conversely, replacing the phenyl group with a thienothiophene block reduced DSSC efficiency to 2.14% for MOS_(2)P-Pyc. Given the proton-accepting ability of the bipyrimidine module, we treated the dye-sensitized TiO_(2) photoanodes with hydroiodic acid(HI), significantly broadening the light absorption range. This treatment greatly enhanced the short-circuit current density of DSSCs owing to the enhanced electron-withdrawing ability of the acceptor. Consequently, the HI-treated MOTS_(2)P-Pyc-based DSSCs achieved the highest power conversion efficiency of 7.12%, comparable to that of the N719 dye at 7.09%. This work reveals the positive role of bipyrimidine in the design of organic sensitizers for DSSC applications.展开更多
The stable coordinated metallo-complexes based on 2,2′:6′,2″-terpyridine(tpy)and its derivatives have been widely researched for various wide-ranging applications in photoelectronics,catalysis,sensor,photoluminesce...The stable coordinated metallo-complexes based on 2,2′:6′,2″-terpyridine(tpy)and its derivatives have been widely researched for various wide-ranging applications in photoelectronics,catalysis,sensor,photoluminescence,and so on.However,the most reported studies ignored the comprehensive comparison between structures modified by different positions and photoluminescence.Herein,we design a series of metallo-complexes which were assembled with tpy substituted triphenylamine(TPA)at different positions and metal ions and explored their photophysical properties.In the solution state,MLE_(2)based on the 5,5″-positions modification showed the highest PLQYs and PL intensity.With the increase of solvent polarity,MLB2exhibit the largest redshift.In the solid state,from MLA_(2)to MLE_(2),the emission colours are gradually red-shifted from yellow to red.The findings in this work may pave a new way to design functional metallo-complexes,not just for PL properties.展开更多
Precision medicine calls for advanced theranostics that integrate controllable diagnostic and therapeutic capabilities into one platform for disease treatment in the early stage.Phototheranostics such as fluorescence ...Precision medicine calls for advanced theranostics that integrate controllable diagnostic and therapeutic capabilities into one platform for disease treatment in the early stage.Phototheranostics such as fluorescence imaging(FLI),photoacoustic imaging(PAI),photodynamic therapy(PDT),and photothermal therapy(PTT)have attracted considerable attention in recent years,which mainly employ different excited-state energy dissipation pathways of a chromophore.According to the Jablonski diagram,FLI is related to the radiative process,PAI and PTT are derived from the nonradiative thermal deactivation,and PDT originates from the triplet state energy,in which these processes are usually competitive.Therefore,it is critically important to precisely tune the photophysical energy transformation processes to realize certain diagnosis and treatment properties in optimal state for boosting biomedical applications.Currently,there are mainly two strategies including chemical structure and aggregate behavior changes that relate to the regulation of excited state energy dissipation.In this review,we will discuss the recent advances of smart molecular probes that the photophysical properties can be regulated by external triggers and their applications in biomedical fields.We will summarize the development of activatable phototheranostic molecular probes in response to stimuli such as reactive oxygen species,pH,light,hypoxia,enzyme and gas.The assembly and disassembly of molecular aggregates that greatly affect the photophysical energy transformation processes will also be highlighted.This review aims to provide valuable insights into the development of more accurate diagnostic and therapeutic systems,thereby advancing the emerging field of smart medicine.展开更多
A series of poly（aryleneethynylene）s containing dibenzosilole unit has been synthesized by palladium-catalyzed Sonogashira cross-coupling reactions with 2,7-diethynyl-9,9-dihexyl-3,6-dimethoxy-9H-dibenzosilole （4）...A series of poly（aryleneethynylene）s containing dibenzosilole unit has been synthesized by palladium-catalyzed Sonogashira cross-coupling reactions with 2,7-diethynyl-9,9-dihexyl-3,6-dimethoxy-9H-dibenzosilole （4） as the key monomer. Their photophysical properties in solution were investigated. All of the polymers showed intense fluorescence with high quantum efficiencies.展开更多
Organic color-tunable phosphorescent materials depend upon multiple emission centers to achieve colortunable phosphorescence with changes in excitation wavelength,temperature,time,and other external factors.Organic co...Organic color-tunable phosphorescent materials depend upon multiple emission centers to achieve colortunable phosphorescence with changes in excitation wavelength,temperature,time,and other external factors.Organic color-tunable phosphorescent materials are becoming increasingly popular due to their potential applications in anticounterfeiting,encryption and sensing.This brief review focuses on the formation of multiple emission centers in organic color-tunable phosphorescent materials and how to ensure that these multiple emission centers can simultaneously emit.In the future,materials with a large color tunable ranges,increased efficiency,and relatively long lives will be developed.展开更多
A novel Ru（Ⅱ） complex [（bpy）2Ru（PBC）]（PF6）2 （PBC = N-[4-（9-carbazole）butyl]-2-（2-pyridyl）benzimidazole） has been synthesized and verified by 1↑H NMR, elemental analysis and X-ray crystallography. The c...A novel Ru（Ⅱ） complex [（bpy）2Ru（PBC）]（PF6）2 （PBC = N-[4-（9-carbazole）butyl]-2-（2-pyridyl）benzimidazole） has been synthesized and verified by 1↑H NMR, elemental analysis and X-ray crystallography. The crystal （C48H40F12N8P2Ru, Mr = 1119.89） belongs to the triclinic system, space group P1, with a = 13.128（4）, b = 13.814（4）, c = 14.184（4） A, α = 84.112（6）, β = 88.473（6）, γ = 78.196（6）°, Z = 2, V = 2504.6（13）A^3, Dc = 1.485 g/cm^3, F（000） = 1132, R = 0.0750 and wR = 0.1896. The Ru atom adopts a distorted-octahedral coordination geometry with the bond distances and bond angles falling in normal ranges. The complex shows an intense metal-to-ligand charge transfer （1MLCT） （dπ（Ru） →π＊（L）） transition （ε ~1.2×10^4 dm^3mol^-1cm^-1） at 457 nm in the UV-Vis absorption spectrum and a strong red phosphorescence at 632 nm in the CH3CN solution at ambient temperature. An efficient intramolecular energy transfer process from the carbazole unit to the [（bpy）2Ru（PB）]^2＋ emissive center exists by selective optical-simulation. Its electrochemical behavior shows multiplicate redox processes based on the metal center, the grafting carbazole moiety and the 2-（2-pyridyl）benzimidazole unit.展开更多
Sonogashira coupling of two different diketopyrrolopyrrole (DPP)-containing dihaloarenes with the same aromatic bisalkyne resulted in two new conjugated polymers with the same backbone but different pendant groups on ...Sonogashira coupling of two different diketopyrrolopyrrole (DPP)-containing dihaloarenes with the same aromatic bisalkyne resulted in two new conjugated polymers with the same backbone but different pendant groups on the DPP moiety. The polymers were found to have designed chemical structures via structural characterizations in comparison with three monomers. The molecular weight measurement further demonstrated the formation of polymers with polydispersity index around 2, consistent with the polycondensation nature of the polymerization based on Sonogashira coupling. Both polymers could dissolve in many organic solvents, and the one with long alkyl side group on DPP moiety had better solubility. Photophysical investigation showed that both polymers had typical absorption/emission of conjugated polymers, and varying the solvent did not have large influence. Compared with other polar solvents, toluene reduced the quantum yield of fluorescence of the polymers, especially for the one with long alkyl pedant group, accompanying with slight red-shift in absorption/emission. The difference in the absorption/emission wavelengths between the polymers was similar to that between the corresponding monomers. Adding water into the THF solution of polymers reduced the emission intensity but no redshift was observed. Discussion about the structure-property relationships was carried out in detail.展开更多
Photophysical processes occurring within organic semiconductors is important for designing and fabricating organic solar cells.Copper phthalocyanine(CuPc)is a typical electron acceptor.In this work,the triplet exciton...Photophysical processes occurring within organic semiconductors is important for designing and fabricating organic solar cells.Copper phthalocyanine(CuPc)is a typical electron acceptor.In this work,the triplet exciton lifetime is prolonged by altering the molecular stacking pattern of the CuPc film.For CuPc thin films,the excited state decays are mainly determined by the triplet-triplet annihilation process.The ultrafast transient absorption measurements indicate that the primary annihilation mechanism is one-dimensional exciton diffusion collision destruction.The decay kinetics show a clearly time-dependent annihilation rate constant withγ∝t^(-1/2).Annihilation rate constants are determined to beγ0=(2.87±0.02)×10^(-20)cm^(3)·s^(-1/2)and(1.42±0.02)×10^(-20)cm^(3)·s^(-1/2)for upright and lyingdown configurations,respectively.Compared to the CuPc thin film with an upright configuration,the thin film with a lying-down configuration shows longer exciton lifetime and higher absorbance,which are beneficial to organic solar cells.The results in this work have important implications on the design and mechanistic understanding of organic optoelectronic devices.展开更多
Photodynamic therapy(PDT)has already been a multifunctional modality for various tumors and nontumorous diseases.However,the development of photosensitizers is relatively delayed,compared with the tremendous progress ...Photodynamic therapy(PDT)has already been a multifunctional modality for various tumors and nontumorous diseases.However,the development of photosensitizers is relatively delayed,compared with the tremendous progress in laser technology.Elsinochrome A(EA),a per-ylenequinonoid pigment from China,has all the typical advantages of perylenequinones.More-over,singlet oxygen quantum yield of EA is superior to other kinds of photosensitizers and EA could be artifially biosynthesized at present,which make it an alternative candidate for PDT.In.this review,the photophysics,photochemistry,photobiology and chemical or biological syntheses of EA photosensitizers are brielty presented.Besides,the future prospects of EA photosensitizers are also proposed.展开更多
基金Project supported by the Science Challenge Project(Grant No.TZ2018001)the National Natural Science Foundation of China(Grant Nos.11872058 and 21802036)the Project of State Key Laboratory of Environment-friendly Energy Materials,and Southwest University of Science and Technology(Grant No.21fksy07)。
文摘Metal-organic frameworks(MOFs),which are self-assembled porous coordination materials,have garnered considerable attention in the fields of optoelectronics,photovoltaic,photochemistry,and photocatalysis due to their diverse structures and excellent tunability.However,the performance of MOF-based optoelectronic applications currently falls short of the industry benchmark.To enhance the performance of MOF materials,it is imperative to undertake comprehensive investigations aimed at gaining a deeper understanding of photophysics and sequentially optimizing properties related to photocarrier transport,recombination,interaction,and transfer.By utilizing femtosecond laser pulses to excite MOFs,time-resolved optical spectroscopy offers a means to observe and characterize these ultrafast microscopic processes.This approach adds the time coordinate as a novel dimension for comprehending the interaction between light and MOFs.Accordingly,this review provides a comprehensive overview of the recent advancements in the photophysics of MOFs and additionally outlines potential avenues for exploring the time domain in the investigation of MOFs.
基金supported by the National Natural Science Foundation of China(Nos.50673094 and 20774102)
文摘A series of new silicon-containing poly（p-arylene vinylene）s （PAVs） with anthracene units in the main chain were synthesized by hydrosilylation reaction. The introduction of organosilicon units improved the solubility of the polymers, and the π-π conjugation of polymeric chains was interrupted. These polymers behaved as blue-green light emitters with their fluorescence maximum at 447-499 nm and quantum yields in the range of 0.28-0.30 in solution.
文摘Hypocrellins are novel photosensitizers from China, which are demonstrated to have significant anti-tumor and anti-virus activity and to be potential photo-dynamic therapy (PDT) agents. As compared with hemato-porphyrin, the only approved photosensitizer, hypocrellins have several advantages, such as easy preparation and easy purification, high triplet quantum yield, high singlet-oxygen quantum yield, high phototoxicity but low dark toxicity, and rapid clearance from normal issues. This article reviews briefly the photophysics, photochemistry and photobiology of hypocrellins on the basis of the domestic and international research results.
基金supported by the National Natural Science Foundation of China(grant nos.22005210,21833005,and 22231009).
文摘Understanding the structure-property relationships in polycyclic conjugated hydrocarbons(PCHs)is crucial in controlling their electronic properties and developing new optically functional materials.Aromaticity is a fundamentally important and intriguing property of numerous organic chemical structures and has stimulated a myriad of experimental and theoretical investigations.Exploiting aromaticity rules for the rational design of optoelectronic materials with the desired photophysical characteristics is a challenging yet fascinating task.Herein we present an in-depth computational and spectroscopic study on the structure-property relationships of dinaphthopentalenes(DNPs).Results highlight that the different fusion patterns between 4nπand 4n+2πunits endow these PCHs with the tunable aromaticity in the ground state/excited state,which leads to the diverse electronic structures and consequently the distinctive excited state photophysics.Accordingly,we propose a combined aromaticity design strategy for rationally modulating and tailoring electronic and optical properties of PCH skeletons.These outcomes not only present a full picture of the excited state dynamics of the DNP system and afford a new class of efficient singlet fission-active materials but also provide some basic guidelines for exploiting aromaticity rules to design and develop new optical function materials.
基金Project suplorted b＇y the National Natural Science Foundation of China （Nos. 50773049, 20974075） and the Program of Innovative Research Team of Soochow University and the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘A series of poly（p-phenylenevinylene）s （PPVs） with good solubility were synthesized from thermal elimination of precursor poly（2,5-didodecyloxy-p-phenylenevinylene） at different temperature via Wessling method. The polymer photophysics were influenced by the thermal elimination condition, which was consistent with NMR and IR characterizations. The additional absorption peak at longer wavelength and the red-shifted emission maximum both in solution and in film, for PPVs obtained at high elimination temperature, indicated the existence of longer conjugated blocks in these systems. The emission maximum for drop-cast film （436 nm） for PPV obtained under 200 ℃ （PPV200） was 16 nm blue shifted to the spin-coated films （452 nm） or 29 nm to the solution （465 nm）. The SEM study showed drop-cast film had the morphology of isolated conjugated particles in the matrix while blurry linear structure was found for spin-coated film, which was consistent with the photophysics. The discussion about this difference was carried out based on the consideration of the flexibility of the polymer chains and different conjugated length of PPV in different states.
基金Project supported by the National Natural Science Foundation of China.
文摘The fluorescence spectra of N--salicylidene-p-(N,N--dimethylamino)aniline have beeninvestigated in various solvents. Three kinds of fluorescence have been found in the solutionsof various concentrations. They are the excited intermediate (EI) which is formed when theproton transfer has occurred but essentially retains the geometry of the enol tautomer, theexciplex (EX) which consists of a ground monomer and an excited state intermediate and theexcited dimer (ED) which is caused by ground state aggregate. The fluorescence lifetimesof the fluorophores have been measured in tetrahydrofuran (THF). Luminescent mechanismhas been discussed based on the fluorescence spectra and the kinetic data of the compound.
文摘9-Fluorenylidenemalononitrile (FDCN) or 1,1 diphenyl 2,2 dicyanoethylene (DPCN) reacted with 10 methyl 9,10 dihydroacridine (AcrH 2) under irradiation ( λ >320 nm) to give couping products. In order to gain further insight into the mechanism of the photo induced reaction, the photophysics of the reactions of FDCN or DPCN with AcrH 2 have been investigated by using UV vis spectroscopy, fluorescence spectroscopy, excitation spectroscopy and time resolved fluorescence spectroscopy, respectively. The results show that FDCN or DPCN interacts with AcrH 2 in the ground states to form a charge transfer complex, which further reacts to give the coupling product upon irradiation.
基金supported by the National Natural Science Foundation of China(Nos.92156021,22350009,and 22101115)Financial Support for Outstanding Talents Training Fund in Shenzhen,the Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002)+2 种基金high level of special funds(No.G03050K003)Introduction of Major Talent Projects in Guangdong Province(No.2019CX01C079)supported by the Center for Computational Science and Engineering at SUSTech.
文摘Azulene-fused acenes demonstrate enhanced stability,unique aromaticity,and distinctive photophysical properties,rendering them significant in organic electronics.In the present study,we report a new type of nonalternant analogue of pentacene incorporating a non-terminal azulene unit.Aromaticity analyses reveal that the five-membered rings in this analogue exhibit antiaromatic.The extensive conjugated aryl substituents on the acene’s side shift the HOMO distributions from the naphthyl ring and metallacycle to the aryl groups,thereby narrowing the HOMO-LUMO energy gap and enhancing absorptions in the low-energy regions.Furthermore,these fused acenes readily react with base rather than acid,resulting in reversible base/acid stimuli responsiveness.
文摘Green-emitting iridium(Ⅲ)complexes were synthesised using chlorobridged dimer(ppy)_(2)Ir_(2)Cl_(2)(ppy)_(2),3-hydroxy-2-methyl-γ-pyranone,2-ethyl-3-hydroxy-4-pyranone,and 5-hydroxy-2-(hydroxymethyl)-1,4-pyranone as the auxiliary ligand.The structure of the target product was characterised by nuclear magnetic resonance spectroscopy(~1H-NMR),infrared spectroscopy(IR)and mass spectrometry(MS),and its thermal stability,photophysical properties and electrochemical properties were investigated.The results show that the decomposition temperatures of Ir1,Ir2 and Ir3 are 349,292 and 200℃,respectively.The maximum emission wavelength of Ir1,Ir2 and Ir3 dissolved in dichloromethane is 491 nm.The HOMO energy level of Ir1,Ir2 and Ir3 are 5.39,-5.38,and-5.30 eV.The LUMO energy levels are-2.86,-2.85,and-2.80 eV,respectively.
基金The project was supported by the National Natural Science Foundation of Chinathe Applied Organic Laboratory,Lanzhou University.
文摘The quenching processes of the excited singlet state of pyrene by triphenylamine,diphenyl- amine and N,N-dibenzylaniline in various solvents at room and lower temperature have been stu- died with both static state fluorescence spectroscopy and fluorescence lifetime techniques.On the basis of experimental data,a preliminary quenching mechanism has been discussed.The geome- trical configuration models of the exciplexes formed between the excited pyrene and aromatic ami- nes in nonpolar solvents were proposed.
基金supported by National Natural Science Foundation of China(Nos.22175074 and 52373182)Jilin Scientific and Technological Development Program(No.20220101054JC).
文摘Quinoidalπ-conjugated structures,a kind of fundamental subunits for organicπ-systems,may produce some intriguing optical,electronic and magnetic properties of polycyclic hydrocarbons(PHs).Herein,we report two thienothiophene-centered ladder-type polycyclic molecules(1 and 2),which possess one quinoidal thienothiophene moiety and two para-quinodimethane(p-QDM)subunits,respectively.As theoretically and experimentally studied,while 1 is a fully closed-shell molecule,2 owns an open-shell structure along with partial contribution of tetraradical state that is induced by the resonance of p-QDM.Moreover,although 2 has a largerπ-conjugated skeleton and open-shell electronic state,it exhibits larger bandgap and blue-shifted absorption.On the other hand,the reversible oxidation activity of 1 enables the preparation of its dication 1^(2+),and the studies on its single-crystal and aromatic structures demonstrate that its two positive charges are delocalized onto the oxygen atoms,thus achieving fullyπ-extended structure and near-infrared absorption.This study not only gains insight into quinoidalπ-subunits,but also provides an important basis for the development of antiaromatic and open-shellπ-electron materials.
基金supported by the National Natural Science Foundation of China(Nos.21776207 and 21576195)。
文摘Molecular engineering is a crucial strategy for improving the photovoltaic performance of dye-sensitized solar cells(DSSCs). Despite the common use of the donor-π bridge-acceptor architecture in designing sensitizers, the underlying structure-performance relationship remains not fully understood. In this study, we synthesized and characterized three sensitizers: MOTP-Pyc, MOS_(2)P-Pyc, and MOTS_(2)P-Pyc, all featuring a bipyrimidine acceptor. Absorption spectra, cyclic voltammetry, and transient photoluminescence spectra reveal a photo-induced electron transfer(PET) process in the excited sensitizers. Electron spin resonance spectroscopy confirmed the presence of charge-separated states. The varying donor and π-bridge structures among the three sensitizers led to differences in their conjugation effect, influencing light absorption abilities and PET processes and ultimately impacting the photovoltaic performance. Among the synthesized sensitizers, MOTP-Pyc demonstrated a DSSC efficiency of 3.04%. Introducing an additional thienothiophene block into the π-bridge improved the DSSC efficiency to 4.47% for MOTS_(2)P-Pyc. Conversely, replacing the phenyl group with a thienothiophene block reduced DSSC efficiency to 2.14% for MOS_(2)P-Pyc. Given the proton-accepting ability of the bipyrimidine module, we treated the dye-sensitized TiO_(2) photoanodes with hydroiodic acid(HI), significantly broadening the light absorption range. This treatment greatly enhanced the short-circuit current density of DSSCs owing to the enhanced electron-withdrawing ability of the acceptor. Consequently, the HI-treated MOTS_(2)P-Pyc-based DSSCs achieved the highest power conversion efficiency of 7.12%, comparable to that of the N719 dye at 7.09%. This work reveals the positive role of bipyrimidine in the design of organic sensitizers for DSSC applications.
基金financially supported by the National Natural Science Foundation of China(Nos.22271116 and 22071079 for M.W)Jilin Provincial Science and Technology Department(No.20230101027JC for M.W.)the fellowship of China Postdoctoral Science Foundation(No.2021M701383 for J.S)。
文摘The stable coordinated metallo-complexes based on 2,2′:6′,2″-terpyridine(tpy)and its derivatives have been widely researched for various wide-ranging applications in photoelectronics,catalysis,sensor,photoluminescence,and so on.However,the most reported studies ignored the comprehensive comparison between structures modified by different positions and photoluminescence.Herein,we design a series of metallo-complexes which were assembled with tpy substituted triphenylamine(TPA)at different positions and metal ions and explored their photophysical properties.In the solution state,MLE_(2)based on the 5,5″-positions modification showed the highest PLQYs and PL intensity.With the increase of solvent polarity,MLB2exhibit the largest redshift.In the solid state,from MLA_(2)to MLE_(2),the emission colours are gradually red-shifted from yellow to red.The findings in this work may pave a new way to design functional metallo-complexes,not just for PL properties.
基金supported by the NSFC(82172081 and 52103168)the Science and Technology Program of Tianjin,China(21JCZDJC00970 and 22JCQNJC01640)Tianjin Key Medical Discipline(Specialty)Construction Project,and the Fundamental Research Funds for the Central Universities(63243137).
文摘Precision medicine calls for advanced theranostics that integrate controllable diagnostic and therapeutic capabilities into one platform for disease treatment in the early stage.Phototheranostics such as fluorescence imaging(FLI),photoacoustic imaging(PAI),photodynamic therapy(PDT),and photothermal therapy(PTT)have attracted considerable attention in recent years,which mainly employ different excited-state energy dissipation pathways of a chromophore.According to the Jablonski diagram,FLI is related to the radiative process,PAI and PTT are derived from the nonradiative thermal deactivation,and PDT originates from the triplet state energy,in which these processes are usually competitive.Therefore,it is critically important to precisely tune the photophysical energy transformation processes to realize certain diagnosis and treatment properties in optimal state for boosting biomedical applications.Currently,there are mainly two strategies including chemical structure and aggregate behavior changes that relate to the regulation of excited state energy dissipation.In this review,we will discuss the recent advances of smart molecular probes that the photophysical properties can be regulated by external triggers and their applications in biomedical fields.We will summarize the development of activatable phototheranostic molecular probes in response to stimuli such as reactive oxygen species,pH,light,hypoxia,enzyme and gas.The assembly and disassembly of molecular aggregates that greatly affect the photophysical energy transformation processes will also be highlighted.This review aims to provide valuable insights into the development of more accurate diagnostic and therapeutic systems,thereby advancing the emerging field of smart medicine.
基金the National Natural Science Foundation of China(NSFC,Nos.50673094 and 20774102) for financial support
文摘A series of poly（aryleneethynylene）s containing dibenzosilole unit has been synthesized by palladium-catalyzed Sonogashira cross-coupling reactions with 2,7-diethynyl-9,9-dihexyl-3,6-dimethoxy-9H-dibenzosilole （4） as the key monomer. Their photophysical properties in solution were investigated. All of the polymers showed intense fluorescence with high quantum efficiencies.
基金financially supported by the Shandong Provincial Natural Science Foundation(Nos.ZR2019YQ19 and ZR2019BEM018)the Project of Shandong Province Higher Educational Science and Technology Program(No.2019KJA026)the National Natural Science Foundation of China(Nos.51403113 and 52072193)。
文摘Organic color-tunable phosphorescent materials depend upon multiple emission centers to achieve colortunable phosphorescence with changes in excitation wavelength,temperature,time,and other external factors.Organic color-tunable phosphorescent materials are becoming increasingly popular due to their potential applications in anticounterfeiting,encryption and sensing.This brief review focuses on the formation of multiple emission centers in organic color-tunable phosphorescent materials and how to ensure that these multiple emission centers can simultaneously emit.In the future,materials with a large color tunable ranges,increased efficiency,and relatively long lives will be developed.
基金Supported by the Natural Science Foundation of Henan Province (No. 102100410221)the Natural Science Foundation of Nanyang Normal University (No. ZX2010012)the Young Core Instructor from the Education Commission of Henan Province
文摘A novel Ru（Ⅱ） complex [（bpy）2Ru（PBC）]（PF6）2 （PBC = N-[4-（9-carbazole）butyl]-2-（2-pyridyl）benzimidazole） has been synthesized and verified by 1↑H NMR, elemental analysis and X-ray crystallography. The crystal （C48H40F12N8P2Ru, Mr = 1119.89） belongs to the triclinic system, space group P1, with a = 13.128（4）, b = 13.814（4）, c = 14.184（4） A, α = 84.112（6）, β = 88.473（6）, γ = 78.196（6）°, Z = 2, V = 2504.6（13）A^3, Dc = 1.485 g/cm^3, F（000） = 1132, R = 0.0750 and wR = 0.1896. The Ru atom adopts a distorted-octahedral coordination geometry with the bond distances and bond angles falling in normal ranges. The complex shows an intense metal-to-ligand charge transfer （1MLCT） （dπ（Ru） →π＊（L）） transition （ε ~1.2×10^4 dm^3mol^-1cm^-1） at 457 nm in the UV-Vis absorption spectrum and a strong red phosphorescence at 632 nm in the CH3CN solution at ambient temperature. An efficient intramolecular energy transfer process from the carbazole unit to the [（bpy）2Ru（PB）]^2＋ emissive center exists by selective optical-simulation. Its electrochemical behavior shows multiplicate redox processes based on the metal center, the grafting carbazole moiety and the 2-（2-pyridyl）benzimidazole unit.
基金financially supported by the Natural Science Foundation of Jiangsu Higher Education Institutions (No. 18KJA430014)the Natural Science Foundation of Jiangsu Province (No. BK20181441)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘Sonogashira coupling of two different diketopyrrolopyrrole (DPP)-containing dihaloarenes with the same aromatic bisalkyne resulted in two new conjugated polymers with the same backbone but different pendant groups on the DPP moiety. The polymers were found to have designed chemical structures via structural characterizations in comparison with three monomers. The molecular weight measurement further demonstrated the formation of polymers with polydispersity index around 2, consistent with the polycondensation nature of the polymerization based on Sonogashira coupling. Both polymers could dissolve in many organic solvents, and the one with long alkyl side group on DPP moiety had better solubility. Photophysical investigation showed that both polymers had typical absorption/emission of conjugated polymers, and varying the solvent did not have large influence. Compared with other polar solvents, toluene reduced the quantum yield of fluorescence of the polymers, especially for the one with long alkyl pedant group, accompanying with slight red-shift in absorption/emission. The difference in the absorption/emission wavelengths between the polymers was similar to that between the corresponding monomers. Adding water into the THF solution of polymers reduced the emission intensity but no redshift was observed. Discussion about the structure-property relationships was carried out in detail.
基金supported by the Open Fund of the State Key Laboratory of Molecular Reaction Dynamics at Dalian Institute of Chemical Physics,Chinese Academy of Sciences(No.SKLMRD-K202108)。
文摘Photophysical processes occurring within organic semiconductors is important for designing and fabricating organic solar cells.Copper phthalocyanine(CuPc)is a typical electron acceptor.In this work,the triplet exciton lifetime is prolonged by altering the molecular stacking pattern of the CuPc film.For CuPc thin films,the excited state decays are mainly determined by the triplet-triplet annihilation process.The ultrafast transient absorption measurements indicate that the primary annihilation mechanism is one-dimensional exciton diffusion collision destruction.The decay kinetics show a clearly time-dependent annihilation rate constant withγ∝t^(-1/2).Annihilation rate constants are determined to beγ0=(2.87±0.02)×10^(-20)cm^(3)·s^(-1/2)and(1.42±0.02)×10^(-20)cm^(3)·s^(-1/2)for upright and lyingdown configurations,respectively.Compared to the CuPc thin film with an upright configuration,the thin film with a lying-down configuration shows longer exciton lifetime and higher absorbance,which are beneficial to organic solar cells.The results in this work have important implications on the design and mechanistic understanding of organic optoelectronic devices.
基金supported by the National Natural Science Foundation of China No.21303223.
文摘Photodynamic therapy(PDT)has already been a multifunctional modality for various tumors and nontumorous diseases.However,the development of photosensitizers is relatively delayed,compared with the tremendous progress in laser technology.Elsinochrome A(EA),a per-ylenequinonoid pigment from China,has all the typical advantages of perylenequinones.More-over,singlet oxygen quantum yield of EA is superior to other kinds of photosensitizers and EA could be artifially biosynthesized at present,which make it an alternative candidate for PDT.In.this review,the photophysics,photochemistry,photobiology and chemical or biological syntheses of EA photosensitizers are brielty presented.Besides,the future prospects of EA photosensitizers are also proposed.
