A simple method for the synthesis of new bithienylethenes bearing a functional group on the cyclopentene moi- ety is developed. Three new photochromic compounds （4a, 4b, 4c） have been successfully synthesized throug...A simple method for the synthesis of new bithienylethenes bearing a functional group on the cyclopentene moi- ety is developed. Three new photochromic compounds （4a, 4b, 4c） have been successfully synthesized through this simple method, and exhibit good photochromic properties with alternate irradiation of ultraviolet and visible light. Furthermore, the fluorescence of compound 4a, which bears a quinoline unit on the cyclopentene, can be modulated via optic and proton dual inputs. Upon excitation by 320 nm light, 4a emits a strong fluorescence at 404 nm. After irradiation with 254 nm light, the emission intensity is reduced due to the fluorescence resonance energy transfers （FRET） from quinoline unit to bithienylethene unit. Moreover, on addition of H~, the fluorescence is quenched completely due to the protonation of the quinoline. In addition, both the FRET and protonation process are reversi- ble, which indicates a potential application in molecular switches and logic gates.展开更多
Three new asymmetrical diarylethenes containing an azaindole moiety and a variable heteroaryl ring have been synthesized. Their properties, such as photochromism, fatigue resistance, thermal stability, acidichromism, ...Three new asymmetrical diarylethenes containing an azaindole moiety and a variable heteroaryl ring have been synthesized. Their properties, such as photochromism, fatigue resistance, thermal stability, acidichromism, and fluorescence, were systematically investigated to elucidate the effects of aromatic stabilization energies （ASE） of the heteroaryl moieties. The results indicated that thermal stability decreased with the increment of the aromatic stabilization energies of the variable heteroaryl rings in the order of thiazyl〈thienyl〈pyrrolyl. Moreover, the dual switching behaviors of these azaindole-containing diarylethenes were also studied by the stimulation of acid/base and light. Addition of trifluoroacetie acid to the solutions of these diarylethenes resulted in obvious hypochromie shifts, and their N-protonated forms also exhibited favorable photochromism.展开更多
Photon upconversion(UC)is one kind of anti-Stokes shift process,which generally requires a combination of two or more low-energy photons to produce one high-energy photon.However,another interesting anti-Stokes proces...Photon upconversion(UC)is one kind of anti-Stokes shift process,which generally requires a combination of two or more low-energy photons to produce one high-energy photon.However,another interesting anti-Stokes process,namely,single-photon-absorption-based upconversion(SPA-UC),can take place by exciting thermally excited vibrational-rotational energy levels of ground state to the first level of excited state.This phenomenon is less involved in organic systems due to the limitation of appropriate materials.Herein,for the first time,we have demonstrated a series of turn-on mode fluorescent diarylethenes,including Thiophene-and p-alkoxybromo-substituted phenyl-substituted derivatives(DAES and DAEC4),which exhibited SPA-UC phenomenon in the closed-ring state.An anti-Stokes shift of 0.36 eV was observed in these molecules,which was the highest value accessible in such UC systems.A relatively high quantum efficiency(13.5%)was evaluated through a relative method by using methylene blue as a standard.Phonon-assisted or hot band absorption was in charge of the achievement of SPA-UC.Besides,the upconverted emission could be switched on/off by cyclization and cycloreversion reaction,regulated by UV–visible light.Thus,this unique finding of the SPA-UC phenomena in photoswitchable diarylethenes might enrich the development of new molecular engineering strategies for designing photofunctional materials.展开更多
The photochromic diarylethene, 1,2-bis[2-methyl-5-（3-trifluoromethylphenyl）-3-thienyl]perfluorocyclopentene （BMTTP）, was synthesized and its photochromic kinetics, fluorescence and X-ray structure were investigate...The photochromic diarylethene, 1,2-bis[2-methyl-5-（3-trifluoromethylphenyl）-3-thienyl]perfluorocyclopentene （BMTTP）, was synthesized and its photochromic kinetics, fluorescence and X-ray structure were investigated. This compound underwent a photochromic reaction both in solution and the single crystalline phase. Its cyclization/cycloreversion process was determined to be zeroth/first order reaction, respectively, and this is the first report on the cyclization/cycloreversion reaction order. In addition, its fluorescence property was also discussed.展开更多
Two novel isomeric photochromic diarylethenes with an indene bridging unit have been prepared by a simple and efficient one-step synthesis method. Their properties, including photochromic behavior, fluorescent propert...Two novel isomeric photochromic diarylethenes with an indene bridging unit have been prepared by a simple and efficient one-step synthesis method. Their properties, including photochromic behavior, fluorescent properties and fatigue resistance, have been investigated. These two isomeric compounds showed photochromic back-and-forth reactions with ultraviolet and visible light both in solution and in PMMA film. Their ring-open forms exhibited appreciable fluorescence, which was quenched by the ring-closed forms. All results indicated that diarylethenes derivatives with indene-aryl bridges exhibited rather high fatigue resistance and good thermally irreversible photochromic properties.展开更多
A series of photochromic diarylethene derivatives containing different fluorophores was synthesized by the Sonogashira coupling reaction and characterized by 1H nuclear magnetic resonance (NMR), 13C NMR and mass spect...A series of photochromic diarylethene derivatives containing different fluorophores was synthesized by the Sonogashira coupling reaction and characterized by 1H nuclear magnetic resonance (NMR), 13C NMR and mass spectroscopy. Photochromic conversion of Cz-MS was observed and its structural change was confirmed by proton NMR. Switchable absorption and emission phenomena were observed for these molecules. These phenomena were attributed to the reversible photochromic fluorescence resonance energy transfer (pcFRET) process. The design of this novel photochromic system of Py-4MS enables information to be processed in a non-destructive manner. This overcomes the problem of the destructive nature of tracking photochromism using ultraviolet (UV)-vis spectroscopy.展开更多
A new photochromic diarylethene, [1-（2-methyl-5-（4-chlorophenyl）-3-thienyl-2-（2- methoxylphenyl）]perfluorocyclopentene （1o, C23HIsC1F6OS） was synthesized and its structure was determined by single-crystal X-ray...A new photochromic diarylethene, [1-（2-methyl-5-（4-chlorophenyl）-3-thienyl-2-（2- methoxylphenyl）]perfluorocyclopentene （1o, C23HIsC1F6OS） was synthesized and its structure was determined by single-crystal X-ray diffraction analysis. The crystal belongs to the triclinic system, space group Pi with a = 9.421（1）, b = 10.4664（1）, c = 11.2988（2）, α= 88.014（1）, β= 76.976（1）,γ= 82.319（1）°, Z= 2, V= 1075.7（2） A3, Dc = 1.509 mg/m3, μ= 0.339 mm-1, F（000） = 496, the final R = 0.0353 and wR = 0.0922 for 3303 observed reflections （I 〉 2σ（I））. Further study demonstrated this compound underwent reversible photochromism with high contrast color-switching between colorless and blue in hexane. Upon UV/Vis irradiation, the fluorescence quenching efficiency can be attached to ca. 98% and recover to the initial state which exhibits high contrast fluorescentswitching between ＂on＂ and ＂off＂ states.展开更多
设计合成了4,5-双(5-氯-2-甲基噻吩-3-基)-1,2-二苯基-1H-咪唑化合物L,通过~1HNMR、^(13)CNMR和元素分析对其分子结构进行表征,并研究了酸效应对其吸收光谱、荧光光谱和热稳定性的影响。结果表明,酸效应对化合物L吸收光谱的影响很小,但...设计合成了4,5-双(5-氯-2-甲基噻吩-3-基)-1,2-二苯基-1H-咪唑化合物L,通过~1HNMR、^(13)CNMR和元素分析对其分子结构进行表征,并研究了酸效应对其吸收光谱、荧光光谱和热稳定性的影响。结果表明,酸效应对化合物L吸收光谱的影响很小,但通过酸效应能够对化合物L的荧光光谱和热稳定性进行有效的调节。另外,化合物L在质子化前后均表现出良好的光致变色性能,并显示出与众不同的"on to on"荧光特性。展开更多
文摘A simple method for the synthesis of new bithienylethenes bearing a functional group on the cyclopentene moi- ety is developed. Three new photochromic compounds （4a, 4b, 4c） have been successfully synthesized through this simple method, and exhibit good photochromic properties with alternate irradiation of ultraviolet and visible light. Furthermore, the fluorescence of compound 4a, which bears a quinoline unit on the cyclopentene, can be modulated via optic and proton dual inputs. Upon excitation by 320 nm light, 4a emits a strong fluorescence at 404 nm. After irradiation with 254 nm light, the emission intensity is reduced due to the fluorescence resonance energy transfers （FRET） from quinoline unit to bithienylethene unit. Moreover, on addition of H~, the fluorescence is quenched completely due to the protonation of the quinoline. In addition, both the FRET and protonation process are reversi- ble, which indicates a potential application in molecular switches and logic gates.
基金This work was supported by the National Natural Science Foundation of China （51373072, 21262015, 21162011, 21363009）, the Project of Jiangxi Advantage Sci-Tech Innovative Team （20142BCB24012）, the Science Funds of Natural Science Foundation of Jiangxi Province （20132BAB203005, 20142BAB203005）, and the Project of the Science Funds of Jiangxi Education Office （KJLD12035, GJJ12587, GJJ14592）.
文摘Three new asymmetrical diarylethenes containing an azaindole moiety and a variable heteroaryl ring have been synthesized. Their properties, such as photochromism, fatigue resistance, thermal stability, acidichromism, and fluorescence, were systematically investigated to elucidate the effects of aromatic stabilization energies （ASE） of the heteroaryl moieties. The results indicated that thermal stability decreased with the increment of the aromatic stabilization energies of the variable heteroaryl rings in the order of thiazyl〈thienyl〈pyrrolyl. Moreover, the dual switching behaviors of these azaindole-containing diarylethenes were also studied by the stimulation of acid/base and light. Addition of trifluoroacetie acid to the solutions of these diarylethenes resulted in obvious hypochromie shifts, and their N-protonated forms also exhibited favorable photochromism.
基金supported by National Natural Science Foundation of China(51673050,91856115,21905065,and 21907060)the Ministry of Science and Technology of the People’s Republic of China(2017YFA0206600 and 2016YFA0203400)support of China Postdoctoral Science Foundation(BX20180082 and 2019M650603).
文摘Photon upconversion(UC)is one kind of anti-Stokes shift process,which generally requires a combination of two or more low-energy photons to produce one high-energy photon.However,another interesting anti-Stokes process,namely,single-photon-absorption-based upconversion(SPA-UC),can take place by exciting thermally excited vibrational-rotational energy levels of ground state to the first level of excited state.This phenomenon is less involved in organic systems due to the limitation of appropriate materials.Herein,for the first time,we have demonstrated a series of turn-on mode fluorescent diarylethenes,including Thiophene-and p-alkoxybromo-substituted phenyl-substituted derivatives(DAES and DAEC4),which exhibited SPA-UC phenomenon in the closed-ring state.An anti-Stokes shift of 0.36 eV was observed in these molecules,which was the highest value accessible in such UC systems.A relatively high quantum efficiency(13.5%)was evaluated through a relative method by using methylene blue as a standard.Phonon-assisted or hot band absorption was in charge of the achievement of SPA-UC.Besides,the upconverted emission could be switched on/off by cyclization and cycloreversion reaction,regulated by UV–visible light.Thus,this unique finding of the SPA-UC phenomena in photoswitchable diarylethenes might enrich the development of new molecular engineering strategies for designing photofunctional materials.
基金Project supported by the National Natural Science Foundation of China （No. 20564001）, the Natural Science Foundation of Jiangxi Province （No. 050017） and the Science Funds of the Education Commission of Jiangxi Province （No. [2005] 140）.
文摘The photochromic diarylethene, 1,2-bis[2-methyl-5-（3-trifluoromethylphenyl）-3-thienyl]perfluorocyclopentene （BMTTP）, was synthesized and its photochromic kinetics, fluorescence and X-ray structure were investigated. This compound underwent a photochromic reaction both in solution and the single crystalline phase. Its cyclization/cycloreversion process was determined to be zeroth/first order reaction, respectively, and this is the first report on the cyclization/cycloreversion reaction order. In addition, its fluorescence property was also discussed.
文摘Two novel isomeric photochromic diarylethenes with an indene bridging unit have been prepared by a simple and efficient one-step synthesis method. Their properties, including photochromic behavior, fluorescent properties and fatigue resistance, have been investigated. These two isomeric compounds showed photochromic back-and-forth reactions with ultraviolet and visible light both in solution and in PMMA film. Their ring-open forms exhibited appreciable fluorescence, which was quenched by the ring-closed forms. All results indicated that diarylethenes derivatives with indene-aryl bridges exhibited rather high fatigue resistance and good thermally irreversible photochromic properties.
基金Project supported by the National Natural Science Foundation of China (No. 20674070)the Natural Science Foundation of Zhejiang Province (No. R404109), China
文摘A series of photochromic diarylethene derivatives containing different fluorophores was synthesized by the Sonogashira coupling reaction and characterized by 1H nuclear magnetic resonance (NMR), 13C NMR and mass spectroscopy. Photochromic conversion of Cz-MS was observed and its structural change was confirmed by proton NMR. Switchable absorption and emission phenomena were observed for these molecules. These phenomena were attributed to the reversible photochromic fluorescence resonance energy transfer (pcFRET) process. The design of this novel photochromic system of Py-4MS enables information to be processed in a non-destructive manner. This overcomes the problem of the destructive nature of tracking photochromism using ultraviolet (UV)-vis spectroscopy.
基金Supported by the National Natural Science Foundation of China(51373072,21363009)the Project of Natural Science Foundation of Jiangxi Province(20142BAB203005)the Program for the Top Young Innovative Talents in University(2013QNBJRC002)
文摘A new photochromic diarylethene, [1-（2-methyl-5-（4-chlorophenyl）-3-thienyl-2-（2- methoxylphenyl）]perfluorocyclopentene （1o, C23HIsC1F6OS） was synthesized and its structure was determined by single-crystal X-ray diffraction analysis. The crystal belongs to the triclinic system, space group Pi with a = 9.421（1）, b = 10.4664（1）, c = 11.2988（2）, α= 88.014（1）, β= 76.976（1）,γ= 82.319（1）°, Z= 2, V= 1075.7（2） A3, Dc = 1.509 mg/m3, μ= 0.339 mm-1, F（000） = 496, the final R = 0.0353 and wR = 0.0922 for 3303 observed reflections （I 〉 2σ（I））. Further study demonstrated this compound underwent reversible photochromism with high contrast color-switching between colorless and blue in hexane. Upon UV/Vis irradiation, the fluorescence quenching efficiency can be attached to ca. 98% and recover to the initial state which exhibits high contrast fluorescentswitching between ＂on＂ and ＂off＂ states.
基金National Natural Science Foundation of China(20564001)the Natural Science Foundation of Jiangxi,China(0620012)the Science Funds of theEducation Office of Jiangxi,China([2005]279).
文摘设计合成了咪唑类二芳基乙烯化合物L,通过1H NMR、13C NMR和元素分析对其分子结构进行了表征,并考察了酸效应对其光致变色性能的影响。结果显示,通过酸效应能够有效调节化合物L的吸收光谱、荧光光谱和热稳定性。化合物L在质子化前后,均表现出良好的光致变色性能,且显示出与众不同的"on to on"的荧光特性。
文摘设计合成了4,5-双(5-氯-2-甲基噻吩-3-基)-1,2-二苯基-1H-咪唑化合物L,通过~1HNMR、^(13)CNMR和元素分析对其分子结构进行表征,并研究了酸效应对其吸收光谱、荧光光谱和热稳定性的影响。结果表明,酸效应对化合物L吸收光谱的影响很小,但通过酸效应能够对化合物L的荧光光谱和热稳定性进行有效的调节。另外,化合物L在质子化前后均表现出良好的光致变色性能,并显示出与众不同的"on to on"荧光特性。
文摘可见光驱动光环化的荧光turn-on型二芳基乙烯分子开关是超分辨显微成像的理想材料,但目前关于该类型分子的报道仍较少.本工作合成了一种基于苯并[b]萘并[1,2-d]噻吩(BNTP)的405 nm可见光驱动光环化的荧光turn-on型二芳基乙烯分子BNTP-BTTO4,同时系统研究了该分子的光物理性能与稳定性,并借助密度泛函理论(DFT)计算厘清了分子实现可见光驱动光环化及荧光turn-on原因.另外,本研究发现BNTP引入后分子表现出比参比分子Ph-BTTO4更优异的抗疲劳性、热稳定性和光稳定性,尤其是在历经200 min 405 nm可见光照射后,BNTP-BTTO4(c)吸收强度只下降4%,光稳定性大幅提升.本研究为设计开发性能优异的可见光驱动光环化的荧光turn-on型二芳基乙烯提供了新的思路.
