Stimuli-responsive two-dimensional (2D) covalent organic frameworks (COFs) with precise structures and permanent porosity have been employed as platforms for sensors. The slight change of backbones inside frameworks l...Stimuli-responsive two-dimensional (2D) covalent organic frameworks (COFs) with precise structures and permanent porosity have been employed as platforms for sensors. The slight change of backbones inside frameworks leads to different electronic states by external stimuli, such as solvent, pH, and water. Herein, we introduced an alkynyl-based building block (ETBA) with high planarity to synthesize two imine-based alkynyl-COFs (ETBA-TAPE-COF and ETBA-PYTA-COF) with high yield, good crystallinity, and chemical stability. Due to the presence of acetylene bonds, ETBA-TAPE-COF does not adopt the completely overlapping AA stacking mode. Slight interlayer displacement occurs along the parallel direction relative to the acetylene linkages, which facilitates lower configurational energy. Additionally, the introduction of pyrene group contributes to high π-electron mobility of ETBA-PYTA-COF. The interactions between electron-withdrawing group (ETBA) and electron-donating group (PYTA) during the processes of protonation and intramolecular charge transfer (ICT) endow ETBA-PYTA-COF with excellent acidochromic and solvatochromic properties, respectively. Based on this, a fluorescence sensor is successfully established, which can be used for rapid response to trace amounts of water in organic solvents. In contrast, ETBA-TAPE-COF does not exhibit these photophysical properties due to its higher HOMO–LUMO gap compared to ETBA-PYTA-COF. This work proposes a new strategy for designing and preparing COFs with unique photophysical properties without introducing additional functional groups.展开更多
A series of ruthenium(II) complexes Ru(fppz)2(CO)L [fppz = 3-trifluoromethyl-5(2-pyridyl)pyrazole; L = pyridine (1), 4-dimethylaminopyridine (2), 4-cyanopyridine (3)] were designed and investigated theo-retically to e...A series of ruthenium(II) complexes Ru(fppz)2(CO)L [fppz = 3-trifluoromethyl-5(2-pyridyl)pyrazole; L = pyridine (1), 4-dimethylaminopyridine (2), 4-cyanopyridine (3)] were designed and investigated theo-retically to explore their electronic structures, absorption, and emissions as well as the solvatochrom-ism. The singlet ground state and triplet excited state geometries were fully optimized at the B3LYP/LANL2DZ and CIS/LANL2DZ level, respectively. The HOMO of 1-3 is composed of dyz(Ru) atom and π(fppz). The LUMO of 1 and 2 is dominantly contributed by π*(fppz) orbital, but that of 3 is con-tributed by π*(L). Absorption and phosphorescence in vacuo, C6H12, and CH3CN media were calculated using the TD-DFT level of theory with the PCM model based on the optimized ground and excited state geometries, respectively. The lowest-lying absorption of 1 and 2 at 387 and 391 nm is attributed to {[dyz(Ru) + π(fppz)] → [π*(fppz)]} transition, but that of 3 at 479 nm is assigned to {[dyz(Ru) + π(fppz)] → [π*(L)]} transition. The phosphorescence of 1 and 2 at 436 and 438 nm originates from 3{[dyz(Ru) + π(fppz)] [π*(fppz)]} excited state, while that of 3 at 606 nm is from 3{[dyz(Ru) + π(fppz)] [π*(L)]} excited state. The calculation results showed that the absorption and emission transition character can be changed from MLCT/ILCT to MLCT/LLCT transition by altering the substituent on the L ligand. The phosphorescence of 1 and 2 does not have solvatochromism, but that of 3 at 606 nm (vacuo), 584 nm (C6H12), and 541 nm (CH3CN) is strongly dependent on the solvent polarity, so introducing elec-tron-withdrawing group on ligand L will induce remarkable solvatochromism.展开更多
This study reports a new nitrogen-doped carbonized polymer dot(CPD)-based solvatochromic probe.Its color-changing for different solvents was explored in detail by the measurements of photophysical parameters(involving...This study reports a new nitrogen-doped carbonized polymer dot(CPD)-based solvatochromic probe.Its color-changing for different solvents was explored in detail by the measurements of photophysical parameters(involving Stokes shifts,fluorescence quantum yield,fluorescence lifetime,radiative decay rate constant,and non-radiative decay rate constant)and the following analyses according to Lippert–Mataga equation and Kamlet–Taft model.The hydrogen bonding effect of the CPD in protonic solvents was semi-quantitatively assessed.It takes charge of the solvatochromic phenomenon,especially in proton solvents.Interestingly,this CPD exhibits two-photon solvatochromism.Moreover,the relations between the photophysical parameters and the surface states of CPD in aprotic and proton solvents were depicted.The results reveal the nitrogen doping in the CPD impacts the up-and down-conversion solvatochromic features from the comparison between N-free and N-doped CPDs in many characterizations.In addition,this N-doped CPD was dispersed into polymer matrices to fabricate tunable solid-state luminescent films,which is another model for evidencing the interactions of the CPD with surroundings.This study is of significance in understanding the surface-state controlled luminescence in the CPDs,and will be beneficial for developing new smart,responsive carbon-based nanoprobes.展开更多
The syntheses of three mixed ligand chelate copper（II） complexes of the type [Cu（L）（acac）（H2O）]BPh4 where acac=acetyleacetonate; L=N,N-dimethyl,N′-benzylethane-1,2-diamine （L1）, N,N-dimethyl, N′-2-methylbe...The syntheses of three mixed ligand chelate copper（II） complexes of the type [Cu（L）（acac）（H2O）]BPh4 where acac=acetyleacetonate; L=N,N-dimethyl,N′-benzylethane-1,2-diamine （L1）, N,N-dimethyl, N′-2-methylbenzylethane-1,2-diamine （L2） or N,N-dimethyl,N′-2-chlorobenzylethane-1,2-diamine （L3） are reported and characterized by elemental analyses, spectroscopic and molar conductance measurements. The X-ray structure of complex 1 shows that the central copper atom is placed in a distorted square pyramidal geometry made by acac and diamine chelate in the base and a H2O molecule on the apex. The prepared complexes are fairly soluble in a large number of organic solvents and show positive solvatochromism. Calculations of SMLR （stepwise multiple linear regression） method was utilized to find the best model explaining the observed solvatochromic behavior and showed that among different solvent parameters, donor number （DN） is a dominant factor responsible for the shift in the d-d absorption band of the complexes to the lower wavenumber with increasing its values. The importance of substituent effect in diamine ligand on the spectral and SMLR measurements is also discussed.展开更多
Environment-sensitive fluorescent probes are commonly utilized in various fields,including fluorescence sensing and imaging.This paper describes the synthesis and photophysical properties of a novel class of solvatoch...Environment-sensitive fluorescent probes are commonly utilized in various fields,including fluorescence sensing and imaging.This paper describes the synthesis and photophysical properties of a novel class of solvatochromic fluorophores that incorporate biisoindolylidene as the core backbone.This study investigates the structure-property relationships of these newly developed fluorophores.The central biisoindolylidene acts as an efficient electron acceptor,and by modifying the aryl ring substituent at the 3,3 position,the photophysical properties of the fluorophores can be significantly enhanced,particularly in terms of photoluminescence quantum efficiency.Furthermore,when an electron-donor group replaces the aryl ring at the 3,3 position,intriguing solvatochromic behavior is observed.This leads to a red-shift in the maximum emission wavelength and an increase in the Stokes shift with increasing solvent polarity.In solvent dimethyl sulfoxide(DMSO),the maximum emission wavelength can reach up to 750 nm,with a Stokes shift of approximately 150 nm.Finally,the potential application of the fluorophore in the detection of volatile acids is explored in a preliminary manner.展开更多
Photonic crystals(PCs)exhibit promising structural coloration properties and possess extensive application prospects in diverse optical fields.However,state-of-the-art inorganic or polymeric PCs show limited adaptivit...Photonic crystals(PCs)exhibit promising structural coloration properties and possess extensive application prospects in diverse optical fields.However,state-of-the-art inorganic or polymeric PCs show limited adaptivity as their configurations are fixed once formed.Herein,bio-organic adaptive PCs are fabricated via drop-casting of amphiphilic guanine-based peptide nucleic acid selfassembled microspheres.The high formation activation energy of up to 81.8 kJ·mol−1 suggests that the self-assembly step dominates the entire process.Therefore,the configurations along with the structural coloration of the supramolecular PCs are sensitive to self-assembly influencing parameters,showing temperature-encoded structural color evolution and solvent polaritydependent solvatochromism.Our findings demonstrate that the supramolecular PCs are adaptive,thus showing promising potential for detection of organic solvents of different polarities in a visual and real-time manner for environmental protection or optical applications.展开更多
Long-term fluorescence monitoring of subcellular organelles is crucial for cellular physiology and pathology studies.Lipid droplets(LDs)are increasingly recognized for their involvement in various biological processes...Long-term fluorescence monitoring of subcellular organelles is crucial for cellular physiology and pathology studies.Lipid droplets(LDs)are increasingly recognized for their involvement in various biological processes,to influence disease development through diverse behaviors However,existing LD probes face challenges in achieving high targeting and long-term monitoring due to poor photostability and long-term phototoxicity.Carbon quantum dots(CQDs)have gained prominence due to their exceptional fluorescence properties,but their prevalent blue excitation wavelength presents difficulties for long-term imaging.Herein,we synthesized red-emissive carbon quantum dot(R-CQDs)with superior photobleaching resistance and red-emission,thus enabling harmlessly fluorescence monitoring of cells longer than3 h.In addition,R-CQD exhibits suitable amphiphilicity and remarkable solvatochromic effect,allowing rapid targeting to LDs for immediate imaging without cumbersome washing steps.Hence,R-CQD shows high performance for extended observation of dynamic LD behavior in various biological processes,which is confirmed by documenting the course of LDs during starvation as well as lipotoxicity.Compared to commercial probes,R-CQD extends live cell imaging time by at least 9-fold,facilitating the study of LD behavioral characteristics under diverse physiological or pathological conditions.This work provides a reliable fluorescence tool for tracking intercellular microenvironment dynamically thus to understand the divers biological or disease mechanism.展开更多
1 Introduction Nonlinear optical materials（NLO） have drawn a great intrest of some scholars and scientists in the last dacades because of their tremendous potential application in optoelectronic. The fabrication of...1 Introduction Nonlinear optical materials（NLO） have drawn a great intrest of some scholars and scientists in the last dacades because of their tremendous potential application in optoelectronic. The fabrication of efficient optoelectron devices is a challenging task because such systems need to meet the stringentable requirements for high optical quality and large and sustainable electro-optical（EO） response. In pursuit of NLO materials with excellent optoelectronic property,展开更多
In this study,6-chloro-4-hydroxy-2-quinolone and 6-flouro-4-hydroxy-2-quinolone were synthesized from corresponding dianilides.These compounds were coupled with some diazotized aromatic amines to give the correspondin...In this study,6-chloro-4-hydroxy-2-quinolone and 6-flouro-4-hydroxy-2-quinolone were synthesized from corresponding dianilides.These compounds were coupled with some diazotized aromatic amines to give the corresponding azo disperse dyes.The structures of the quinolone derivatives and new azo dyes were confirmed by UV-vis,FT-IR,;H NMR and elemental analysis.展开更多
A new series of (E)-5-[2-(N-hexylcarbazolyl)vinyl]furan chromophores with various accepters have been synthesized by the Knoevenagel condensation of (E)-5-[2-(N- hexylcarbazolyl) vinyl]-2-furaldehydes with malononitri...A new series of (E)-5-[2-(N-hexylcarbazolyl)vinyl]furan chromophores with various accepters have been synthesized by the Knoevenagel condensation of (E)-5-[2-(N- hexylcarbazolyl) vinyl]-2-furaldehydes with malononitrile, 1,3-diethyl-2-thiobarbituric acid, or 3-phenyl-5-isoxazol one, respectively. They are characterized by H-1-NMR, FT- IR, UV-VIS, MS and elemental analysis, and have shown strong solvatochromism and high thermal stability.展开更多
Binary mixtures of 1,3-dialkylimidazolium based ionic liquids （ILs） and water were selected as solvent systems to investigate the solute-solvent and solvent-solvent interactions on the preferential solvation of solv...Binary mixtures of 1,3-dialkylimidazolium based ionic liquids （ILs） and water were selected as solvent systems to investigate the solute-solvent and solvent-solvent interactions on the preferential solvation of solvatochromic indicators at 25 ℃. Empirical solvatochromic pa- rameters, dipolarity/polarizability （π^＊）, hydrogen-bond donor acidity （α）, hydrogen-bond acceptor basicity （β）, and Reichardt＇s polarity parameters （ET^N） were measured from the ultraviolet-visible spectral shifts of 4-nitroaniline, 4-nitroanisole, and Reichardt＇s dye. The solvent properties of the IL-water mixtures were found to be influenced by IL type and IL mole fraction （XIL）. All these studied systems showed the non-ideal behavior. The max- imum deviation to ideality for the solvatochromic parameters can be obtained in the XIL range from 0.i to 0.3. For most of the binary mixtures, the π^＊ values showed the synergistic effects instead of the ETN, α and β values. The observed synergy extent was dependent on the studied systems, such as the dye indicator and IL type. A preferential solvation model was utilized to gather information on the molecular interactions in the mixtures. The dye indicator was preferentially solvated on the following trend： IL〉IL-water complex〉water.展开更多
Seven electron-deficient A_2 B type H_3-triarylcorroles have been synthesized and characterized. The solvent dependence of the electronic absorption and magnetic circular dichroism（MCD） spectra and a series of TD-DF...Seven electron-deficient A_2 B type H_3-triarylcorroles have been synthesized and characterized. The solvent dependence of the electronic absorption and magnetic circular dichroism（MCD） spectra and a series of TD-DFT calculations have been used to analyze trends in the electronic structures. Significant differences are observed in the optical spectra when solvents of differing polarity are used,which can be assigned to the effect of NH-tautomerism.展开更多
Three novel nonlinear chromophores with symmetric D-π-D molecular structure and extended conjugated length were synthesized. Solvatochromism analysis shows great symmetric intramolecular charge transfer occurring in ...Three novel nonlinear chromophores with symmetric D-π-D molecular structure and extended conjugated length were synthesized. Solvatochromism analysis shows great symmetric intramolecular charge transfer occurring in chromophores by the enhancement in the dipole moment between the ground and excited states. The properties of optical power limiting induced by three-photon absorption （3PA） are demonstrated. Large 3PA coefficients and the corresponding molecular cross sections as high as 10^-74 cm^6s^2 were obtained for nanosecond laser pulses at 1.06μm from nonlinear transmission measurements.展开更多
Fluorescence properties of 1-pheny1-3-(4'-nitrophenyl) pyrazoline (PNP) were studied inbulk polymerization process of methylmethacrylate (MMA). The fluorescence intensity of PNPwas enhanced and the emission maximu...Fluorescence properties of 1-pheny1-3-(4'-nitrophenyl) pyrazoline (PNP) were studied inbulk polymerization process of methylmethacrylate (MMA). The fluorescence intensity of PNPwas enhanced and the emission maximum was blue shifted with the polymerization progress. Inthe period of auto-acceleration of the polymerization the enhancement of fluorescence intensityand blue shift of peak wavelength in spectra could be observed evidently. This means that thesolvatochromic properties of PNP are influenced not only by the solvent polarity but also by theviscosity of the medium (especially by the phase transitiott). In solid state PNP emits from thecharge transfer excited state without solvent relaxation. The transient emission spectra and theresults from Bakhshiev model of solvent relaxation coincide with that from the polymerizationexperiment.展开更多
Amphiphilic methanofullerene 1 exhibits strong tendency to form aggregates in THFH2O solvent mixtures. Two different aggregation processes induced by either varying the solvent composition or upon standing have been ...Amphiphilic methanofullerene 1 exhibits strong tendency to form aggregates in THFH2O solvent mixtures. Two different aggregation processes induced by either varying the solvent composition or upon standing have been found. Concentration has great influence on the aggregation process. Paralleling to the UV-Vis changes, an unusual solvatochromism has been observed in these two different processes.展开更多
Two alkyl substituted polythiophene derivatives: poly(3-hexylthiophene)(P3HT) and poly(3-decylthiophene)(P3DT), have synthesized by oxidation coupling polymerization of 3-alkylthiophene using iron(III) chloride as cat...Two alkyl substituted polythiophene derivatives: poly(3-hexylthiophene)(P3HT) and poly(3-decylthiophene)(P3DT), have synthesized by oxidation coupling polymerization of 3-alkylthiophene using iron(III) chloride as catalyst in chloroform. While both polymers in pure chloroform solution have maximum absorption at approximately same wavelength of 440nm, they behave differently with respect to changes observed on their UV-visible and photoluminescence spectra when the quality of the poor solvent is changed in good solvent (chloroform) / poor solvent (methanol) mixtures. With increasing volume fraction of methanol in mixtures, the absorption spectra of P3HT and P3DT red-shift, peaking at maximum wavelength of 495nm (P3HT) and 510nm(P3DT). Furthermore, the absorption spectra of the two polymers in chloroform blue-shift as the temperature rises. P3HT shows 4.73nm blue-shifts at 50℃ in contrast to the case at 20℃, while P3DT blue-shifts about 5.04nm. The photoluminescence spectra of the two polymers in mixed solution are also investigated, which show that the luminescence spectra shift to longer wavelength with an accompanying drop in the PL intensity as methanol is increased. The absorption and emission spectra of the two polymers in a poor solvent and a thin film are similar, which indicate that a similar longer conjugation length in the two cases. It could conclude that the polymers exist almost the same conformations and aggregations in both a poor solvent and a thin film. P3DT exhibits more sensitive spectra properties (big red-shifts in both absorption and luminescence spectra in poor solvents and large blue-shifts at high temperature) with contrast to P3HT, which imply that long side alkyl may improve the chromic properties of the polymer.展开更多
Hexakis(4-methoxyphenyl)benzene (HPB-OMe(1)) and hexakis(2,6-dimethyl-4-methoxyphenyl)benzene (HPB-OMe(2)) were synthesized via organometallic complex catalysis. The treatment of HPB-OMe(1) with FeCl3 caused cyclodehy...Hexakis(4-methoxyphenyl)benzene (HPB-OMe(1)) and hexakis(2,6-dimethyl-4-methoxyphenyl)benzene (HPB-OMe(2)) were synthesized via organometallic complex catalysis. The treatment of HPB-OMe(1) with FeCl3 caused cyclodehydrogenation at two positions to yield an oligophenylene with an indeno[1,2-b]fluorene structure (IF-OMe). Deprotection of the methoxy groups of these compounds was conducted by treatment with BBr3. Deprotonation of the OH groups of HPB-OH(1), HPB-OH(2), and IF-OH through treatment with NaH caused a bathochromic shift in the absorption and photoluminescence (PL) peaks. The bathochromic shift of the deprotonated species increased with the donor number (DN) of the solvents. These observations can be explained as the consequence of intramolecular charge transfer (ICT) from the ONa groups to the inner benzene rings.展开更多
The dot products mu(g)beta(CT) of first hyperpolarizability and ground state dipole moment of two merocarbocyanines were measured experimentally with solvatochromism and compared to the values obtained by AM1/FF calcu...The dot products mu(g)beta(CT) of first hyperpolarizability and ground state dipole moment of two merocarbocyanines were measured experimentally with solvatochromism and compared to the values obtained by AM1/FF calculation. The comparable result was also obtained by the measurement of second harmonic generation (SHG) for LB film of dye II. The mu(g)beta(CT) of dye II is larger than that of the well known NLO chromophore 4-N, N-dimethylamino-4'-nitrostilbene (DANS).展开更多
Three discrete tetrahedral metallo-supramolecular cages were designed and constructed using truxenepended base ligands.Owing to the synergistic rigidifying effect of unsymmetric cyano-substituted oligo(pphenylene-viny...Three discrete tetrahedral metallo-supramolecular cages were designed and constructed using truxenepended base ligands.Owing to the synergistic rigidifying effect of unsymmetric cyano-substituted oligo(pphenylene-vinylene)(u-COPV)suspended by the truxene skeleton,the resulting supramolecular cages were confirmed to exhibit significant aggregation-induced emission(AIE)accompanied by an interesting solvatochromic fluorescent behavior as well as a porous honeycomb-like state during aggregation.In particular,the anti-counterfeiting performance and emission behaviors of the cages in the solid state under external hydrostatic pressure were investigated.展开更多
It was found that Dynol-604, a non-fluorous and no silicon-containing nonionic surfactant, was soluble in supercritical (SC) CO2. The phase behavior of SC CO2/Dynol-604/water system was studied. The results showed t...It was found that Dynol-604, a non-fluorous and no silicon-containing nonionic surfactant, was soluble in supercritical (SC) CO2. The phase behavior of SC CO2/Dynol-604/water system was studied. The results showed that one-phase water-in-CO2 microemulsions could be formed. The solubilization of methyl orange in the microemulsions proved further the existence of water domain in the microemulsions.展开更多
基金supported by the National Natural Science Foundation of China(22172055)the Science Fund for Distinguished Young Scholars of Guangdong Province(2023B1515040026)+1 种基金the Key Area Research and Development Program of Guangdong Province(2023B0101200008)the Natural Science Foundation of Guangdong Province(2022A1515011892).
文摘Stimuli-responsive two-dimensional (2D) covalent organic frameworks (COFs) with precise structures and permanent porosity have been employed as platforms for sensors. The slight change of backbones inside frameworks leads to different electronic states by external stimuli, such as solvent, pH, and water. Herein, we introduced an alkynyl-based building block (ETBA) with high planarity to synthesize two imine-based alkynyl-COFs (ETBA-TAPE-COF and ETBA-PYTA-COF) with high yield, good crystallinity, and chemical stability. Due to the presence of acetylene bonds, ETBA-TAPE-COF does not adopt the completely overlapping AA stacking mode. Slight interlayer displacement occurs along the parallel direction relative to the acetylene linkages, which facilitates lower configurational energy. Additionally, the introduction of pyrene group contributes to high π-electron mobility of ETBA-PYTA-COF. The interactions between electron-withdrawing group (ETBA) and electron-donating group (PYTA) during the processes of protonation and intramolecular charge transfer (ICT) endow ETBA-PYTA-COF with excellent acidochromic and solvatochromic properties, respectively. Based on this, a fluorescence sensor is successfully established, which can be used for rapid response to trace amounts of water in organic solvents. In contrast, ETBA-TAPE-COF does not exhibit these photophysical properties due to its higher HOMO–LUMO gap compared to ETBA-PYTA-COF. This work proposes a new strategy for designing and preparing COFs with unique photophysical properties without introducing additional functional groups.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20573042, 20703015, and 20333050)
文摘A series of ruthenium(II) complexes Ru(fppz)2(CO)L [fppz = 3-trifluoromethyl-5(2-pyridyl)pyrazole; L = pyridine (1), 4-dimethylaminopyridine (2), 4-cyanopyridine (3)] were designed and investigated theo-retically to explore their electronic structures, absorption, and emissions as well as the solvatochrom-ism. The singlet ground state and triplet excited state geometries were fully optimized at the B3LYP/LANL2DZ and CIS/LANL2DZ level, respectively. The HOMO of 1-3 is composed of dyz(Ru) atom and π(fppz). The LUMO of 1 and 2 is dominantly contributed by π*(fppz) orbital, but that of 3 is con-tributed by π*(L). Absorption and phosphorescence in vacuo, C6H12, and CH3CN media were calculated using the TD-DFT level of theory with the PCM model based on the optimized ground and excited state geometries, respectively. The lowest-lying absorption of 1 and 2 at 387 and 391 nm is attributed to {[dyz(Ru) + π(fppz)] → [π*(fppz)]} transition, but that of 3 at 479 nm is assigned to {[dyz(Ru) + π(fppz)] → [π*(L)]} transition. The phosphorescence of 1 and 2 at 436 and 438 nm originates from 3{[dyz(Ru) + π(fppz)] [π*(fppz)]} excited state, while that of 3 at 606 nm is from 3{[dyz(Ru) + π(fppz)] [π*(L)]} excited state. The calculation results showed that the absorption and emission transition character can be changed from MLCT/ILCT to MLCT/LLCT transition by altering the substituent on the L ligand. The phosphorescence of 1 and 2 does not have solvatochromism, but that of 3 at 606 nm (vacuo), 584 nm (C6H12), and 541 nm (CH3CN) is strongly dependent on the solvent polarity, so introducing elec-tron-withdrawing group on ligand L will induce remarkable solvatochromism.
基金the National Natural Science Foundation of China(No.21873039)Interdisciplinary Integration Innovation Project of Jilin University(No.JLUXKJC2020106).
文摘This study reports a new nitrogen-doped carbonized polymer dot(CPD)-based solvatochromic probe.Its color-changing for different solvents was explored in detail by the measurements of photophysical parameters(involving Stokes shifts,fluorescence quantum yield,fluorescence lifetime,radiative decay rate constant,and non-radiative decay rate constant)and the following analyses according to Lippert–Mataga equation and Kamlet–Taft model.The hydrogen bonding effect of the CPD in protonic solvents was semi-quantitatively assessed.It takes charge of the solvatochromic phenomenon,especially in proton solvents.Interestingly,this CPD exhibits two-photon solvatochromism.Moreover,the relations between the photophysical parameters and the surface states of CPD in aprotic and proton solvents were depicted.The results reveal the nitrogen doping in the CPD impacts the up-and down-conversion solvatochromic features from the comparison between N-free and N-doped CPDs in many characterizations.In addition,this N-doped CPD was dispersed into polymer matrices to fabricate tunable solid-state luminescent films,which is another model for evidencing the interactions of the CPD with surroundings.This study is of significance in understanding the surface-state controlled luminescence in the CPDs,and will be beneficial for developing new smart,responsive carbon-based nanoprobes.
文摘The syntheses of three mixed ligand chelate copper（II） complexes of the type [Cu（L）（acac）（H2O）]BPh4 where acac=acetyleacetonate; L=N,N-dimethyl,N′-benzylethane-1,2-diamine （L1）, N,N-dimethyl, N′-2-methylbenzylethane-1,2-diamine （L2） or N,N-dimethyl,N′-2-chlorobenzylethane-1,2-diamine （L3） are reported and characterized by elemental analyses, spectroscopic and molar conductance measurements. The X-ray structure of complex 1 shows that the central copper atom is placed in a distorted square pyramidal geometry made by acac and diamine chelate in the base and a H2O molecule on the apex. The prepared complexes are fairly soluble in a large number of organic solvents and show positive solvatochromism. Calculations of SMLR （stepwise multiple linear regression） method was utilized to find the best model explaining the observed solvatochromic behavior and showed that among different solvent parameters, donor number （DN） is a dominant factor responsible for the shift in the d-d absorption band of the complexes to the lower wavenumber with increasing its values. The importance of substituent effect in diamine ligand on the spectral and SMLR measurements is also discussed.
基金supported by the National Natural Science Foundation of China(Nos.22225107,22301302)。
文摘Environment-sensitive fluorescent probes are commonly utilized in various fields,including fluorescence sensing and imaging.This paper describes the synthesis and photophysical properties of a novel class of solvatochromic fluorophores that incorporate biisoindolylidene as the core backbone.This study investigates the structure-property relationships of these newly developed fluorophores.The central biisoindolylidene acts as an efficient electron acceptor,and by modifying the aryl ring substituent at the 3,3 position,the photophysical properties of the fluorophores can be significantly enhanced,particularly in terms of photoluminescence quantum efficiency.Furthermore,when an electron-donor group replaces the aryl ring at the 3,3 position,intriguing solvatochromic behavior is observed.This leads to a red-shift in the maximum emission wavelength and an increase in the Stokes shift with increasing solvent polarity.In solvent dimethyl sulfoxide(DMSO),the maximum emission wavelength can reach up to 750 nm,with a Stokes shift of approximately 150 nm.Finally,the potential application of the fluorophore in the detection of volatile acids is explored in a preliminary manner.
基金the National Key Research and Development Program of China(No.2022YFE0100800)the National Natural Science Foundation of China(No.52175551)。
文摘Photonic crystals(PCs)exhibit promising structural coloration properties and possess extensive application prospects in diverse optical fields.However,state-of-the-art inorganic or polymeric PCs show limited adaptivity as their configurations are fixed once formed.Herein,bio-organic adaptive PCs are fabricated via drop-casting of amphiphilic guanine-based peptide nucleic acid selfassembled microspheres.The high formation activation energy of up to 81.8 kJ·mol−1 suggests that the self-assembly step dominates the entire process.Therefore,the configurations along with the structural coloration of the supramolecular PCs are sensitive to self-assembly influencing parameters,showing temperature-encoded structural color evolution and solvent polaritydependent solvatochromism.Our findings demonstrate that the supramolecular PCs are adaptive,thus showing promising potential for detection of organic solvents of different polarities in a visual and real-time manner for environmental protection or optical applications.
基金supported by the National Natural Science Foundation of China(Nos.52003178,52273141 and 51973132)Natural Science Foundation of Sichuan Province(No.2023NSFSC0338)。
文摘Long-term fluorescence monitoring of subcellular organelles is crucial for cellular physiology and pathology studies.Lipid droplets(LDs)are increasingly recognized for their involvement in various biological processes,to influence disease development through diverse behaviors However,existing LD probes face challenges in achieving high targeting and long-term monitoring due to poor photostability and long-term phototoxicity.Carbon quantum dots(CQDs)have gained prominence due to their exceptional fluorescence properties,but their prevalent blue excitation wavelength presents difficulties for long-term imaging.Herein,we synthesized red-emissive carbon quantum dot(R-CQDs)with superior photobleaching resistance and red-emission,thus enabling harmlessly fluorescence monitoring of cells longer than3 h.In addition,R-CQD exhibits suitable amphiphilicity and remarkable solvatochromic effect,allowing rapid targeting to LDs for immediate imaging without cumbersome washing steps.Hence,R-CQD shows high performance for extended observation of dynamic LD behavior in various biological processes,which is confirmed by documenting the course of LDs during starvation as well as lipotoxicity.Compared to commercial probes,R-CQD extends live cell imaging time by at least 9-fold,facilitating the study of LD behavioral characteristics under diverse physiological or pathological conditions.This work provides a reliable fluorescence tool for tracking intercellular microenvironment dynamically thus to understand the divers biological or disease mechanism.
基金Supported by the National Natural Science Foundation of China(No.50573023)the Program for Changjiang Scholars and Innovative Research Team in University,China(No.IRTO422)
文摘1 Introduction Nonlinear optical materials（NLO） have drawn a great intrest of some scholars and scientists in the last dacades because of their tremendous potential application in optoelectronic. The fabrication of efficient optoelectron devices is a challenging task because such systems need to meet the stringentable requirements for high optical quality and large and sustainable electro-optical（EO） response. In pursuit of NLO materials with excellent optoelectronic property,
文摘In this study,6-chloro-4-hydroxy-2-quinolone and 6-flouro-4-hydroxy-2-quinolone were synthesized from corresponding dianilides.These compounds were coupled with some diazotized aromatic amines to give the corresponding azo disperse dyes.The structures of the quinolone derivatives and new azo dyes were confirmed by UV-vis,FT-IR,;H NMR and elemental analysis.
基金This work was supported by the NationalNatural Science Foundation of China(No.29774018).
文摘A new series of (E)-5-[2-(N-hexylcarbazolyl)vinyl]furan chromophores with various accepters have been synthesized by the Knoevenagel condensation of (E)-5-[2-(N- hexylcarbazolyl) vinyl]-2-furaldehydes with malononitrile, 1,3-diethyl-2-thiobarbituric acid, or 3-phenyl-5-isoxazol one, respectively. They are characterized by H-1-NMR, FT- IR, UV-VIS, MS and elemental analysis, and have shown strong solvatochromism and high thermal stability.
文摘Binary mixtures of 1,3-dialkylimidazolium based ionic liquids （ILs） and water were selected as solvent systems to investigate the solute-solvent and solvent-solvent interactions on the preferential solvation of solvatochromic indicators at 25 ℃. Empirical solvatochromic pa- rameters, dipolarity/polarizability （π^＊）, hydrogen-bond donor acidity （α）, hydrogen-bond acceptor basicity （β）, and Reichardt＇s polarity parameters （ET^N） were measured from the ultraviolet-visible spectral shifts of 4-nitroaniline, 4-nitroanisole, and Reichardt＇s dye. The solvent properties of the IL-water mixtures were found to be influenced by IL type and IL mole fraction （XIL）. All these studied systems showed the non-ideal behavior. The max- imum deviation to ideality for the solvatochromic parameters can be obtained in the XIL range from 0.i to 0.3. For most of the binary mixtures, the π^＊ values showed the synergistic effects instead of the ETN, α and β values. The observed synergy extent was dependent on the studied systems, such as the dye indicator and IL type. A preferential solvation model was utilized to gather information on the molecular interactions in the mixtures. The dye indicator was preferentially solvated on the following trend： IL〉IL-water complex〉water.
基金financially supported by the National Natural Science Foundation of China(No.21171076)Natural Science Foundation of Jiangsu Province(No.BK20160499)to XL and WZ and an NRF of South Africa CSUR grant(uid:93627)to JM
文摘Seven electron-deficient A_2 B type H_3-triarylcorroles have been synthesized and characterized. The solvent dependence of the electronic absorption and magnetic circular dichroism（MCD） spectra and a series of TD-DFT calculations have been used to analyze trends in the electronic structures. Significant differences are observed in the optical spectra when solvents of differing polarity are used,which can be assigned to the effect of NH-tautomerism.
基金This work was supported by the National Natural Science Foundation of China （No.90201016）.
文摘Three novel nonlinear chromophores with symmetric D-π-D molecular structure and extended conjugated length were synthesized. Solvatochromism analysis shows great symmetric intramolecular charge transfer occurring in chromophores by the enhancement in the dipole moment between the ground and excited states. The properties of optical power limiting induced by three-photon absorption （3PA） are demonstrated. Large 3PA coefficients and the corresponding molecular cross sections as high as 10^-74 cm^6s^2 were obtained for nanosecond laser pulses at 1.06μm from nonlinear transmission measurements.
基金This project was supported by the National Natural Science Foundation of China
文摘Fluorescence properties of 1-pheny1-3-(4'-nitrophenyl) pyrazoline (PNP) were studied inbulk polymerization process of methylmethacrylate (MMA). The fluorescence intensity of PNPwas enhanced and the emission maximum was blue shifted with the polymerization progress. Inthe period of auto-acceleration of the polymerization the enhancement of fluorescence intensityand blue shift of peak wavelength in spectra could be observed evidently. This means that thesolvatochromic properties of PNP are influenced not only by the solvent polarity but also by theviscosity of the medium (especially by the phase transitiott). In solid state PNP emits from thecharge transfer excited state without solvent relaxation. The transient emission spectra and theresults from Bakhshiev model of solvent relaxation coincide with that from the polymerizationexperiment.
文摘Amphiphilic methanofullerene 1 exhibits strong tendency to form aggregates in THFH2O solvent mixtures. Two different aggregation processes induced by either varying the solvent composition or upon standing have been found. Concentration has great influence on the aggregation process. Paralleling to the UV-Vis changes, an unusual solvatochromism has been observed in these two different processes.
基金National Natural Science Foundation of China (60277002)
文摘Two alkyl substituted polythiophene derivatives: poly(3-hexylthiophene)(P3HT) and poly(3-decylthiophene)(P3DT), have synthesized by oxidation coupling polymerization of 3-alkylthiophene using iron(III) chloride as catalyst in chloroform. While both polymers in pure chloroform solution have maximum absorption at approximately same wavelength of 440nm, they behave differently with respect to changes observed on their UV-visible and photoluminescence spectra when the quality of the poor solvent is changed in good solvent (chloroform) / poor solvent (methanol) mixtures. With increasing volume fraction of methanol in mixtures, the absorption spectra of P3HT and P3DT red-shift, peaking at maximum wavelength of 495nm (P3HT) and 510nm(P3DT). Furthermore, the absorption spectra of the two polymers in chloroform blue-shift as the temperature rises. P3HT shows 4.73nm blue-shifts at 50℃ in contrast to the case at 20℃, while P3DT blue-shifts about 5.04nm. The photoluminescence spectra of the two polymers in mixed solution are also investigated, which show that the luminescence spectra shift to longer wavelength with an accompanying drop in the PL intensity as methanol is increased. The absorption and emission spectra of the two polymers in a poor solvent and a thin film are similar, which indicate that a similar longer conjugation length in the two cases. It could conclude that the polymers exist almost the same conformations and aggregations in both a poor solvent and a thin film. P3DT exhibits more sensitive spectra properties (big red-shifts in both absorption and luminescence spectra in poor solvents and large blue-shifts at high temperature) with contrast to P3HT, which imply that long side alkyl may improve the chromic properties of the polymer.
文摘Hexakis(4-methoxyphenyl)benzene (HPB-OMe(1)) and hexakis(2,6-dimethyl-4-methoxyphenyl)benzene (HPB-OMe(2)) were synthesized via organometallic complex catalysis. The treatment of HPB-OMe(1) with FeCl3 caused cyclodehydrogenation at two positions to yield an oligophenylene with an indeno[1,2-b]fluorene structure (IF-OMe). Deprotection of the methoxy groups of these compounds was conducted by treatment with BBr3. Deprotonation of the OH groups of HPB-OH(1), HPB-OH(2), and IF-OH through treatment with NaH caused a bathochromic shift in the absorption and photoluminescence (PL) peaks. The bathochromic shift of the deprotonated species increased with the donor number (DN) of the solvents. These observations can be explained as the consequence of intramolecular charge transfer (ICT) from the ONa groups to the inner benzene rings.
文摘The dot products mu(g)beta(CT) of first hyperpolarizability and ground state dipole moment of two merocarbocyanines were measured experimentally with solvatochromism and compared to the values obtained by AM1/FF calculation. The comparable result was also obtained by the measurement of second harmonic generation (SHG) for LB film of dye II. The mu(g)beta(CT) of dye II is larger than that of the well known NLO chromophore 4-N, N-dimethylamino-4'-nitrostilbene (DANS).
基金the National Natural Science Foundation of China(Nos.22101267,21672192,21803059,U2004191,U1904212,21801063)for financial support。
文摘Three discrete tetrahedral metallo-supramolecular cages were designed and constructed using truxenepended base ligands.Owing to the synergistic rigidifying effect of unsymmetric cyano-substituted oligo(pphenylene-vinylene)(u-COPV)suspended by the truxene skeleton,the resulting supramolecular cages were confirmed to exhibit significant aggregation-induced emission(AIE)accompanied by an interesting solvatochromic fluorescent behavior as well as a porous honeycomb-like state during aggregation.In particular,the anti-counterfeiting performance and emission behaviors of the cages in the solid state under external hydrostatic pressure were investigated.
基金The authors are grateful to the National Natural Science Foundation of China and Ministry of Science and Technology for the financial support(29725308,G20000781).
文摘It was found that Dynol-604, a non-fluorous and no silicon-containing nonionic surfactant, was soluble in supercritical (SC) CO2. The phase behavior of SC CO2/Dynol-604/water system was studied. The results showed that one-phase water-in-CO2 microemulsions could be formed. The solubilization of methyl orange in the microemulsions proved further the existence of water domain in the microemulsions.
