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
Smart multi-stimuli responsive organic materials have become increasingly favored due to their advantages of high stability and easy regulation.In this study,a cyanostilbene derivative((αZ)-2-chloro-α-[(4-methoxyphe...Smart multi-stimuli responsive organic materials have become increasingly favored due to their advantages of high stability and easy regulation.In this study,a cyanostilbene derivative((αZ)-2-chloro-α-[(4-methoxyphenyl)methylene]-5-pyridinehyde,TAR)was successfully synthesized,and its polymorphs(TAR-1 and TAR-2)exhibited multiple responsive behaviors under different stimulus conditions.TAR-1 is supposed to have excellent mechanical properties,while TAR-2 shows fascinating heterotropic photochromism(green-cyan-yellow)under different intensities of ultraviolet(UV)irradiation,which has never been reported in previous studies.Further investigation revealed that this was attributed to different degrees of[2+2]cycloaddition induced by UV light.In addition,both polymorphs could be protonated during Trifluoroacetic acid fuming and deprotonate automatically after fuming,accompanied by the significant variation in fluorescence.Finally,two scenarios were designed based on their unique stimuli-responsive properties,which proved their promising potential in fields of information security and anti-counterfeiting encryption.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
1,3,3-tnmethyl-spiro[mdolino-2,3’-[2H]naphtho[2,1-b] [1,4]oxazine(SP1) and 1,3,3-trimen-thyl-9-methoxy-spiro[indolino2,3’-[2H]naphtho[2,1-b] [ 1,4]oxazine] (SP2) react with hydrochloric acid to form the complex SP H...1,3,3-tnmethyl-spiro[mdolino-2,3’-[2H]naphtho[2,1-b] [1,4]oxazine(SP1) and 1,3,3-trimen-thyl-9-methoxy-spiro[indolino2,3’-[2H]naphtho[2,1-b] [ 1,4]oxazine] (SP2) react with hydrochloric acid to form the complex SP HCl in isopropanol solution at room temperature The absorption maxima of these complexes are 440 and 463 nm respectively In acidic media,the opening form of spirooxazine can react with hydrochloric acid to form the complex PMC HCl via zwittenon form The absorption spectra of PMC HCl are obviously hypsochromic shifted compared with the reported spectra of the complex in neutral media In the mean time,the thermal stability of the complex is increased.The first order kinetics for the decoloration process of the acidichromic product of the opening form was determined and the lifetimes of these products are 180 and 200 s,respectively.展开更多
A series of novel spirooxazine（SPO） derivatives containing nitrogen heterocycles was synthesized and characterized by 1H NMR spectra, Fourier transform infrared（FTIR） spectra, mass spectra（MS） and elemental anal...A series of novel spirooxazine（SPO） derivatives containing nitrogen heterocycles was synthesized and characterized by 1H NMR spectra, Fourier transform infrared（FTIR） spectra, mass spectra（MS） and elemental analy- sis, and their photochromic behaviors were fully investigated in solvents and polymer media. In solvents, they dis- played excellent photochromism properties such as high photochromic response and fast thermal bleaching rate. Es- pecially, compounds 1 and 4 exhibited strong fluorescence intensities in dichloromethane solution. It was additionally found that compound 4 showed high fatigue resistence in poly（methyl methacrylate）（PMMA） film, and the thermal decay curves were fitted with biexponential function in PMMA film.展开更多
A new Schiff base containing carbazole group (CzSB) was synthesized. Although the compound can not form stable monolayer at air/water interface itself, it does form stable monolayers by mixing with stearic acids as v...A new Schiff base containing carbazole group (CzSB) was synthesized. Although the compound can not form stable monolayer at air/water interface itself, it does form stable monolayers by mixing with stearic acids as verified from the surface pressure area measurements. The mixed monolayers can be deposited by vertical dipping method. UV Spectroscopic studies of the mixed LB films reveal a broadening and red shift of the absorption spectra compared to those of CzSB in the ethanol solution, which confirms the formation of organized aggregates of the compounds in the mixed LB films. An ordered LB film was obtained as confirmed by using low angle X ray diffraction. The mixed LB film shows acidichromism, that is, the colors of the LB films can be reversibly changed upon exposing to HCl and NH 3 gas alternatively. On the basis of FT IR measurement, it is proposed that the protontation of the imine group in the compound is the reason for the acidichromism.展开更多
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supported by the National Natural Science Foundation of China(22208237)China Postdoctoral Science Foundation(2021M692382)。
文摘Smart multi-stimuli responsive organic materials have become increasingly favored due to their advantages of high stability and easy regulation.In this study,a cyanostilbene derivative((αZ)-2-chloro-α-[(4-methoxyphenyl)methylene]-5-pyridinehyde,TAR)was successfully synthesized,and its polymorphs(TAR-1 and TAR-2)exhibited multiple responsive behaviors under different stimulus conditions.TAR-1 is supposed to have excellent mechanical properties,while TAR-2 shows fascinating heterotropic photochromism(green-cyan-yellow)under different intensities of ultraviolet(UV)irradiation,which has never been reported in previous studies.Further investigation revealed that this was attributed to different degrees of[2+2]cycloaddition induced by UV light.In addition,both polymorphs could be protonated during Trifluoroacetic acid fuming and deprotonate automatically after fuming,accompanied by the significant variation in fluorescence.Finally,two scenarios were designed based on their unique stimuli-responsive properties,which proved their promising potential in fields of information security and anti-counterfeiting encryption.
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Project supported by the National Natural Science Foundation of Chinathe Chinese Academy of Sciences
文摘1,3,3-tnmethyl-spiro[mdolino-2,3’-[2H]naphtho[2,1-b] [1,4]oxazine(SP1) and 1,3,3-trimen-thyl-9-methoxy-spiro[indolino2,3’-[2H]naphtho[2,1-b] [ 1,4]oxazine] (SP2) react with hydrochloric acid to form the complex SP HCl in isopropanol solution at room temperature The absorption maxima of these complexes are 440 and 463 nm respectively In acidic media,the opening form of spirooxazine can react with hydrochloric acid to form the complex PMC HCl via zwittenon form The absorption spectra of PMC HCl are obviously hypsochromic shifted compared with the reported spectra of the complex in neutral media In the mean time,the thermal stability of the complex is increased.The first order kinetics for the decoloration process of the acidichromic product of the opening form was determined and the lifetimes of these products are 180 and 200 s,respectively.
基金the National Natural Science Foundation of China（Nos.20971071, 20602020）.
文摘A series of novel spirooxazine（SPO） derivatives containing nitrogen heterocycles was synthesized and characterized by 1H NMR spectra, Fourier transform infrared（FTIR） spectra, mass spectra（MS） and elemental analy- sis, and their photochromic behaviors were fully investigated in solvents and polymer media. In solvents, they dis- played excellent photochromism properties such as high photochromic response and fast thermal bleaching rate. Es- pecially, compounds 1 and 4 exhibited strong fluorescence intensities in dichloromethane solution. It was additionally found that compound 4 showed high fatigue resistence in poly（methyl methacrylate）（PMMA） film, and the thermal decay curves were fitted with biexponential function in PMMA film.
文摘A new Schiff base containing carbazole group (CzSB) was synthesized. Although the compound can not form stable monolayer at air/water interface itself, it does form stable monolayers by mixing with stearic acids as verified from the surface pressure area measurements. The mixed monolayers can be deposited by vertical dipping method. UV Spectroscopic studies of the mixed LB films reveal a broadening and red shift of the absorption spectra compared to those of CzSB in the ethanol solution, which confirms the formation of organized aggregates of the compounds in the mixed LB films. An ordered LB film was obtained as confirmed by using low angle X ray diffraction. The mixed LB film shows acidichromism, that is, the colors of the LB films can be reversibly changed upon exposing to HCl and NH 3 gas alternatively. On the basis of FT IR measurement, it is proposed that the protontation of the imine group in the compound is the reason for the acidichromism.
