The CIDNP observations indicated that photoreaction of methylfurans with chloranil resulted not only furylmethyl hydroxyphenyl ethers via radical pairs but induced furyl radical isomerization to the derivatives of cyc...The CIDNP observations indicated that photoreaction of methylfurans with chloranil resulted not only furylmethyl hydroxyphenyl ethers via radical pairs but induced furyl radical isomerization to the derivatives of cyclopropene,propadiene and pyran.展开更多
Molecular design, synthesis and photochromic properties of spirooxazines and fulgides are described. In the case of fulgides, the change of the substituents may lead to different photochromic properties and different ...Molecular design, synthesis and photochromic properties of spirooxazines and fulgides are described. In the case of fulgides, the change of the substituents may lead to different photochromic properties and different photoreactions of the kind of compounds. In photochromic process of pyrryl-substituted fulgides, the excited singlet state is the mam species, but the excited triplet state is also involved. However, no excited triplet state has been observed in cyclization of aryl-substituted fulgides. In the case of spirooxazines, the substituents at 2’-position have great effect on the formation of photoproduct and on the mechanism of photoreaction. The increase of steric hindrance of the 2’-position substituent gives rise to the decrease of the quantum yield for the formation of photochromic merocyanine (PMC) and the increase of the relative quantum yield for the charge separated twist intermediate (CT).展开更多
The liquid crystalline polymers with photosensitive groups can self-assemble.When the polymer film is exposed to linearly polarized ultraviolet(LPUV),it can react a polarization-axis selective photoreaction.A small op...The liquid crystalline polymers with photosensitive groups can self-assemble.When the polymer film is exposed to linearly polarized ultraviolet(LPUV),it can react a polarization-axis selective photoreaction.A small optical anisotropy presented from an axis-selective photoreaction of the photosensitive groups.When annealing in the liquid crystal temperature,a large optical anisotropic change of the polymer film was appeared.In the paper,the photoreaction property of polymer containing coumarin photosensitive group was measured by an ultraviolet spectrum method.The photochemical reaction property corresponding to the different exposure temperature and energy was investigated.The orientation performance at different annealing conditions was also conducted.The results indicated that when the exposure temperature is 70℃and 130℃,ΔA achieve the maximum and the corresponding exposure energy is the minimum.The corresponding DP is around 45%,when the exposure energy is 320 mJ/cm^(2) and 384 mJ/cm^(2),and the annealing temperature is 160℃,the correspondingΔA and S reach the maximum,ΔA=0.22 and S=0.048,respectively.展开更多
Drug synergistic effects refer to combinations that have a greater impact than individual drugs,which are often but sometimes harmful.Predicting synergism via computational methods like intelligence(AI)is popular,yet ...Drug synergistic effects refer to combinations that have a greater impact than individual drugs,which are often but sometimes harmful.Predicting synergism via computational methods like intelligence(AI)is popular,yet experimental validation remains challenging.DNA-programmed labeling(DPAL)is a method for target based on drug-target binding,minimizing interference from photoreactive groups and tags,which has the advantages of high sensitivity and low impact on drug activities[1–3].In the present study,we utilized the DPAL method to reveal the synergistic targets of the three main components(bufalin,cinobufagin,and resibufogenin(BCR))of cinobufacini injection with anti-hepatocarcinoma activities.展开更多
In this study,we showed that BiO Br nanoplates prepared at different pH values have substratedependent photocatalytic activities under visible-light irradiation. The BiO Br nanoplates synthesized at pH 1（BOB-1） degr...In this study,we showed that BiO Br nanoplates prepared at different pH values have substratedependent photocatalytic activities under visible-light irradiation. The BiO Br nanoplates synthesized at pH 1（BOB-1） degraded salicylic acid more effectively than did those obtained at pH 3（BOB-3）,but the order of their photocatalytic activities in rhodamine B（RhB） degradation were reversed. Electrochemical Mott–Schottky and zeta-potential measurements showed that BOB-1 had a more positive valence band and lower surface charge,leading to superior photocatalytic activity in salicylic acid degradation under visible light. However,BOB-3 was more powerful in RhB degradation because larger numbers of superoxide radicals were generated via electron injection from the excited RhB to its more negative conduction band under visible-light irradiation; this was confirmed using active oxygen species measurements and electron spin resonance analysis. This study deepens our understanding of the origins of organic-pollutant-dependent photoreactivities of semiconductors,and will help in designing highly active photocatalysts for environmental remediation.展开更多
Methylmercury（MeHg） bioaccumulation is a growing concern in ecosystems worldwide. The absorption of solar radiation by dissolved organic matter（DOM） and other photoreactive ligands can convert MeHg into less toxic...Methylmercury（MeHg） bioaccumulation is a growing concern in ecosystems worldwide. The absorption of solar radiation by dissolved organic matter（DOM） and other photoreactive ligands can convert MeHg into less toxic forms of mercury through photodemethylation. In this study, spectral changes and photoreactivity of DOM were measured to assess the potential to control photoreactions and predict in situ MeHg concentration. Water samples collected from a series of lakes in southwestern Nova Scotia in June, August, and September were exposed to controlled ultraviolet-A（UV-A） radiation for up to 24 hr. Dissolved organic matter photoreactivity, measured as the loss of absorbance at 350 nm at constant UV-A irradiation, was positively dependent on the initial DOM concentration in lake waters（r^2=0.94）. This relationship was consistent over time with both DOM concentration and photoreactivity increasing from summer into fall across lakes. Lake in situ MeHg concentration was positively correlated with DOM concentration and likely catchment transport in June（r = 0.77） but not the other sampling months. Despite a consistent seasonal variation in both DOM and Fe, and their respective correlations with MeHg, no discernable seasonal trend in MeHg was observed. However, a 3-year dataset from the 6 study lakes revealed a positive correlation between DOM concentration and both Fe（r = 0.91） and MeHg concentrations（r = 0.51） suggesting a more dominant landscape mobility control on MeHg.The DOM-MeHg relationships observed in these lakes highlights the need to examine DOM photoreactivity controls on MeHg transport and availability in natural waters particularly given future climate perturbations.展开更多
A novel nelnatic liquid crystal compound containing a cinnamoyl moiety （PCPC） and a typically cholesteric liquid crystal cholesteryl cinnamate （CC） were synthesized to explore the mechanism ofcinnamoyl compounds, ...A novel nelnatic liquid crystal compound containing a cinnamoyl moiety （PCPC） and a typically cholesteric liquid crystal cholesteryl cinnamate （CC） were synthesized to explore the mechanism ofcinnamoyl compounds, and the chemical structures of photodimerization were confirmed by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectral analysis. The photoreaction behaviors of these two cinnamoyl compounds in mesomorphic state and solution were investigated, UV-Vis spectral analysis was used to analyze the photoproduct. The results show that the photochemistry of PCPC in nematic state involves both photodimerization and photoisomerization, while CC shows a complex reaction which can be divided into three parts, and this has enabled us to present new data and interpretations regarding the [2＋2] photocycloaddition reaction. Additionally, the results of UV-Vis spectral analysis in solutions strongly suggest that UV-Vis spectral analysis can be used to study the kinetic behaviors of cinnamoyl moiety photoreaction.展开更多
Fulgide 1-E doped in polystyrene polymer films was heated at various annealing temperatures.Upon irradiation with UV light(366 nm),fulgide 1-E undergoes a conrotatory ring closure to the pink colored closed form 1-C.T...Fulgide 1-E doped in polystyrene polymer films was heated at various annealing temperatures.Upon irradiation with UV light(366 nm),fulgide 1-E undergoes a conrotatory ring closure to the pink colored closed form 1-C.The later color was switched back to the original color when the films were irradiated with white light.The kinetics of photocoloration and photobleaching processes were followed spectrophotometrically by monitoring the absorbance of the ring closed product 1-C at itsλ_(max) of 525 nm.The first-...展开更多
Drug-induced phototoxicity is elicited by exposure of skin and/or eyes to topical or systemic administration of chemicals,followed by exposure to sunlight.For photosafety testing,a new screening strategy,employing in ...Drug-induced phototoxicity is elicited by exposure of skin and/or eyes to topical or systemic administration of chemicals,followed by exposure to sunlight.For photosafety testing,a new screening strategy,employing in vitro photochemical/photobiological and in vivo cassette-dosing pharmacokinetic(PK)studies,was proposed[1,2].The screening system provided reliable phototoxic predictions of tested chemicals at least within the same chemical series;however,the applicability of the proposed strategy is not fully understood.展开更多
Organic matters in drinking water of Kaschin-Beck disease areas were extracted. Then analyses and characterization were performed by means of multiply chemical and physical methods. The results did not show the obviou...Organic matters in drinking water of Kaschin-Beck disease areas were extracted. Then analyses and characterization were performed by means of multiply chemical and physical methods. The results did not show the obvious difference in the frame structure of humic substances and the structure of rmcromolecular compounds in the drinking water of disease and non-disease areas, but the difference in the contents of some micromolecular compounds and radicals. The investigation also includes the preliminary research on the photoreaction of drinking water from disease and non-disease areas and the accumulation of natural organic matter in the bone of tested animals.展开更多
Photochemical reactions of 3-methylindole,carbazole,benzimidazole with fused polycyclic aromatic hydrocarbons in solid state were investigated,The structures of 4 new compounds were confirmed by IR,UV,\+1HNNR,MS and e...Photochemical reactions of 3-methylindole,carbazole,benzimidazole with fused polycyclic aromatic hydrocarbons in solid state were investigated,The structures of 4 new compounds were confirmed by IR,UV,\+1HNNR,MS and elemental analysis.The structure of compounds 3.6 was established by X-ray crystallography.展开更多
We investigate theoretically the temperature effects on the evolutions of both bright and dark screening spatial solitons in biased two-photon photorefractive crystals.For a stable bright or dark two-photon screening ...We investigate theoretically the temperature effects on the evolutions of both bright and dark screening spatial solitons in biased two-photon photorefractive crystals.For a stable bright or dark two-photon screening spatial soliton originally formed in a crystal at a given temperature,when the crystal temperature changes,it will evolve into another stable screening soliton if the temperature change is quite small,while it will become unstable or break down if the temperature change is large enough.The spatial shape of a stable two-photon screening spatial soliton can be changed by appropriately adjusting the crystal temperature.展开更多
The synthesis of syn-photodimer from 1,4-dihydropyridine without 4-aryl was studied, and its single crystal was obtained （C22H30N2O8, Mr= 450.48）. It crystallizes in monoclinic, space group P21/c with a = 11.937（2...The synthesis of syn-photodimer from 1,4-dihydropyridine without 4-aryl was studied, and its single crystal was obtained （C22H30N2O8, Mr= 450.48）. It crystallizes in monoclinic, space group P21/c with a = 11.937（2）, b = 20.913（4）, c = 9.763（2） A,β = 108.46（3）°, V= 2311.9（8） ,A^3, Z= 4, Dc = 1.294 g/cm^3,/7（000） = 960,μ = 0.099 mm^- 1, R = 0.0640 and wR = 0.1464 for 4077 unique reflections with 1598 observed ones （I 〉 2σ（I）. It is shown that the whole molecular structure of the title compound is a twist-boat conformation, and the two double bonds have a trend of potential intramolecular reaction under high-energy irradiation.展开更多
The density functional theory（DFT） calculations were performed to investigate a typical Norrish/Yang type II photoreaction of 5-methylbicyclo[1.1.1]-pentanyl ketone.The results reveal the essential correlation betwe...The density functional theory（DFT） calculations were performed to investigate a typical Norrish/Yang type II photoreaction of 5-methylbicyclo[1.1.1]-pentanyl ketone.The results reveal the essential correlation between structures on the one hand and energies,on the other hand,of the reactants,transition states and products based on both singlet ground（S0） and triplet excited（T1） potential energy surfaces.The feasible mechanism indicates that an intramolecular Norrish/Yang cyclization reaction takes place via H-abstraction to obtain the sole chiral cyclobutanol photoproduct.The located crossing point plays an important role in the cyclization process,which permits intersystem crossing（ISC） from T1 to S0 state.The rate-determining step may be to experience ISC between two different potential energy surfaces,requiring sufficient time for electron spin reversion,i.e.,spin multiplicity alteration.These conclusions are further confirmed by the second-order M ller-Plesset perturbation theory（MP2） calculations.展开更多
Controllable photoreaction transition of photosensitizers(PSs)provides a highly promising approach for achieving efficient photodynamic therapy(PDT).However,tumor microenvironment-triggered phototransition remains a s...Controllable photoreaction transition of photosensitizers(PSs)provides a highly promising approach for achieving efficient photodynamic therapy(PDT).However,tumor microenvironment-triggered phototransition remains a significant challenge and has not yet been reported.In this work,we develop a hydrogen bond self-assembly(HBSA)strategy that is triggered by the acidic tumor microenvironment to enable the photodynamic transition of tetra(4-carboxylphenyl)porphyrin(TCPP)PSs from type Ⅱ to type Ⅰ reactions.Upon self-assembly of TCPP monomers into TCPP assemblies(TCPP-ass),the generated reactive oxygen species shift from singlet oxygen to superoxide anions,which induces caspase-3/GSDME-mediated programmed pyroptosis,enabling rapid and complete solid tumor elimination with minimized adverse effects and enhanced therapeutic efficacy.Crucially,the HBSA process occurs exclusively within tumor cells,and this tumor-specific self-assembly strategy not only utilizes high tissue penetration of TCPP molecular-PSs,but also avoids phototoxicity caused by the formation and accumulation of TCPP-ass nano-PSs in normal tissue,providing an innovative approach for precise cancer therapy.展开更多
Graphitic carbon nitride(g-C_(3)N_(4))nanosheets exfoliated from their bulk-sized counterparts are limited by a quantum size effect-induced widened bandgap.In this work,an(NH_(4))_(2)S_(2)O_(8)(APS)induced thermal exf...Graphitic carbon nitride(g-C_(3)N_(4))nanosheets exfoliated from their bulk-sized counterparts are limited by a quantum size effect-induced widened bandgap.In this work,an(NH_(4))_(2)S_(2)O_(8)(APS)induced thermal exfoliation approach is introduced to fabricate O-doped g-C_(3)N_(4)nanosheets(OCNs).During this calcination process,the thermal decomposition products(NH_(3)and H_(2)SO_(4))from APS not only efficiently promote delamination,but also introduce O doping into the g-C_(3)N_(4)structure,realizing the synchronization control of the electronic structure and morphology.展开更多
Photoreactive coordination polymers are important platforms for the implementation of tailored solidstate photochemical reactions.These crystalline compounds can also be employed as photo-controlled intelligent materi...Photoreactive coordination polymers are important platforms for the implementation of tailored solidstate photochemical reactions.These crystalline compounds can also be employed as photo-controlled intelligent materials for the design and manufacture of advanced devices.Herein,a comb-like photoreactive coordination polymer,formulated as{[Zn(5-Cl-1,3-bdc)(H_(2)O)(2,3-ppe)]·H_(2)O}_(n)(1),was prepared based on the hydrothermal reaction between Zn(NO_(3))2·6H_(2)O,5-chlorobenzene-1,3-dicarboxylic acid(5-Cl-1,3-H_(2)BDC)and 1-(2-pyridyl)-2-(3-pyridyl)-ethylene(2,3-ppe).Upon irradiation with sunlight,the 1H NMR spectroscopy,UV-vis absorption spectroscopy and single crystal X-ray diffraction analyses results indicated that 1 can undergo a[^(2+)2]photocycloaddition reaction and thus generate a unique ladder-like coordination chain{[Zn(5-Cl-1,3-bdc)(H_(2)O)(2,3-bpbpcb)_(0.5)]·H_(2)O}n(1a,2,3-bpbpcb=1,3-bis(2-pyridyl)-2,4-bis(3-pyridyl)cyclobutane)via single-crystal to single-crystal(SCSC)transformation.Upon irradiation of UV light with a wavelength of 254 nm,the newly formed coordination chain 1a can undergo a reversible cycloreversion reaction and return to 1.The reversible photo-controllable cycloaddition-cycloreversion reaction between 1 and 1a also exhibits an interesting behavior of photo-switchable fluorescence.The reversible structural transformation and fluorescence switching behavior of 1 make it a potential photo-controlled intelligent material for optical information storage,optical anti-counterfeiting,fluorescence sensors and other fields.展开更多
The application of supramolecular host–vip chemistry for controlled photoreactivity and molecular sensing is a highly important field of modern inorganic and physical chemistry.One key aspect is the formation of th...The application of supramolecular host–vip chemistry for controlled photoreactivity and molecular sensing is a highly important field of modern inorganic and physical chemistry.One key aspect is the formation of the triplet state after photoexcitation.Applications of zinc ion Schiff-base derivatives for this purpose are rarely reported in the literature and there is still a lack of investigation into the triplet state formation of these supramolecular complexes.展开更多
Developing fully fusedπ-conjugated molecules with characteristic self-assembly and selective host–vip interaction by a wet chemistry approach remains very challenging.A series of fully fused thiophene-benzene alte...Developing fully fusedπ-conjugated molecules with characteristic self-assembly and selective host–vip interaction by a wet chemistry approach remains very challenging.A series of fully fused thiophene-benzene alternating ribbons,BDTh-nT(n=2–6),have been successfully synthesized.X-ray crystallography analysis indicates that BDTh-nT adopt nearly planar configurations,with sulfur atoms oriented regularly in theπ-conjugated skeleton.With the increase ofπ-conjugated length,the ability of self-assembly shows a trend of increasing while the host–vip binding between BDTh-nT and spherical vip C_(60)exhibits obvious selectivity.Only BDTh-4T with appropriateπ-conjugated length can be combined with the spherical vip C_(60)by shape recognition.In addition,it is worth noting that BDTh-nT show a conjugated-length-dependent photoreactivity,in which BDTh-4/5/6T can achieve a fluorescence transition from blue-violet to light yellow/blue-white/orange-yellow under the excitation of 365 nm ultraviolet light.Our investigations will not only shed light on the supramolecular chemistry but also provide a strategy for design and precise synthesis of thienoacenes with desirable properties.展开更多
1 Results Absolute asymmetric synthesis by means of solid-state reaction of chiral crystals self-assembled from achiral molecules is an attractive and promising methodology for asymmetric synthesis because it is not n...1 Results Absolute asymmetric synthesis by means of solid-state reaction of chiral crystals self-assembled from achiral molecules is an attractive and promising methodology for asymmetric synthesis because it is not necessary to employ any external chiral source like a chiral catalyst.In order to design reliably absolute asymmetric syntheses in the solid state,it is inevitable to prepare and predict the formation of chiral crystals from achiral compounds.We have prepared a number of chiral cocrystals co...展开更多
文摘The CIDNP observations indicated that photoreaction of methylfurans with chloranil resulted not only furylmethyl hydroxyphenyl ethers via radical pairs but induced furyl radical isomerization to the derivatives of cyclopropene,propadiene and pyran.
基金Project supported by the National Natural Science Foundation of China
文摘Molecular design, synthesis and photochromic properties of spirooxazines and fulgides are described. In the case of fulgides, the change of the substituents may lead to different photochromic properties and different photoreactions of the kind of compounds. In photochromic process of pyrryl-substituted fulgides, the excited singlet state is the mam species, but the excited triplet state is also involved. However, no excited triplet state has been observed in cyclization of aryl-substituted fulgides. In the case of spirooxazines, the substituents at 2’-position have great effect on the formation of photoproduct and on the mechanism of photoreaction. The increase of steric hindrance of the 2’-position substituent gives rise to the decrease of the quantum yield for the formation of photochromic merocyanine (PMC) and the increase of the relative quantum yield for the charge separated twist intermediate (CT).
文摘The liquid crystalline polymers with photosensitive groups can self-assemble.When the polymer film is exposed to linearly polarized ultraviolet(LPUV),it can react a polarization-axis selective photoreaction.A small optical anisotropy presented from an axis-selective photoreaction of the photosensitive groups.When annealing in the liquid crystal temperature,a large optical anisotropic change of the polymer film was appeared.In the paper,the photoreaction property of polymer containing coumarin photosensitive group was measured by an ultraviolet spectrum method.The photochemical reaction property corresponding to the different exposure temperature and energy was investigated.The orientation performance at different annealing conditions was also conducted.The results indicated that when the exposure temperature is 70℃and 130℃,ΔA achieve the maximum and the corresponding exposure energy is the minimum.The corresponding DP is around 45%,when the exposure energy is 320 mJ/cm^(2) and 384 mJ/cm^(2),and the annealing temperature is 160℃,the correspondingΔA and S reach the maximum,ΔA=0.22 and S=0.048,respectively.
基金supported by the National Natural Science Foundation of China(Grant No.:82003711)Open Research Fund of Basic Medicine College(Grant No.:JCKFKT-MS-001)+2 种基金Shanghai Natural Science Foundation(Grant No.:23ZR1477600)Young Elite Scientists Sponsorship Program by CAST(Program No.:2022QNRC001)Shanghai Sailing Program(Program No.:24YF2758300).
文摘Drug synergistic effects refer to combinations that have a greater impact than individual drugs,which are often but sometimes harmful.Predicting synergism via computational methods like intelligence(AI)is popular,yet experimental validation remains challenging.DNA-programmed labeling(DPAL)is a method for target based on drug-target binding,minimizing interference from photoreactive groups and tags,which has the advantages of high sensitivity and low impact on drug activities[1–3].In the present study,we utilized the DPAL method to reveal the synergistic targets of the three main components(bufalin,cinobufagin,and resibufogenin(BCR))of cinobufacini injection with anti-hepatocarcinoma activities.
基金supported by the National Natural Science Funds for Distinguished Young Scholars(21425728)the National Natural Science Foundation of China(21173093+4 种基金211770482127308821477044)the Key Project of Natural Science Foundation of Hubei Province(2013CFA114)the the Fundamental Research Funds for the Central Universities(CCNU14Z01001 CCNU14KFY002)~~
文摘In this study,we showed that BiO Br nanoplates prepared at different pH values have substratedependent photocatalytic activities under visible-light irradiation. The BiO Br nanoplates synthesized at pH 1（BOB-1） degraded salicylic acid more effectively than did those obtained at pH 3（BOB-3）,but the order of their photocatalytic activities in rhodamine B（RhB） degradation were reversed. Electrochemical Mott–Schottky and zeta-potential measurements showed that BOB-1 had a more positive valence band and lower surface charge,leading to superior photocatalytic activity in salicylic acid degradation under visible light. However,BOB-3 was more powerful in RhB degradation because larger numbers of superoxide radicals were generated via electron injection from the excited RhB to its more negative conduction band under visible-light irradiation; this was confirmed using active oxygen species measurements and electron spin resonance analysis. This study deepens our understanding of the origins of organic-pollutant-dependent photoreactivities of semiconductors,and will help in designing highly active photocatalysts for environmental remediation.
基金provided from the National Science and Engineering Council (NSERC) of Canada in the form of a discovery grant (#341960-2013)Canada Research Chair (#950-203477)an NSERC CREATE (#371177-2010)scholarship to S.J.K
文摘Methylmercury（MeHg） bioaccumulation is a growing concern in ecosystems worldwide. The absorption of solar radiation by dissolved organic matter（DOM） and other photoreactive ligands can convert MeHg into less toxic forms of mercury through photodemethylation. In this study, spectral changes and photoreactivity of DOM were measured to assess the potential to control photoreactions and predict in situ MeHg concentration. Water samples collected from a series of lakes in southwestern Nova Scotia in June, August, and September were exposed to controlled ultraviolet-A（UV-A） radiation for up to 24 hr. Dissolved organic matter photoreactivity, measured as the loss of absorbance at 350 nm at constant UV-A irradiation, was positively dependent on the initial DOM concentration in lake waters（r^2=0.94）. This relationship was consistent over time with both DOM concentration and photoreactivity increasing from summer into fall across lakes. Lake in situ MeHg concentration was positively correlated with DOM concentration and likely catchment transport in June（r = 0.77） but not the other sampling months. Despite a consistent seasonal variation in both DOM and Fe, and their respective correlations with MeHg, no discernable seasonal trend in MeHg was observed. However, a 3-year dataset from the 6 study lakes revealed a positive correlation between DOM concentration and both Fe（r = 0.91） and MeHg concentrations（r = 0.51） suggesting a more dominant landscape mobility control on MeHg.The DOM-MeHg relationships observed in these lakes highlights the need to examine DOM photoreactivity controls on MeHg transport and availability in natural waters particularly given future climate perturbations.
文摘A novel nelnatic liquid crystal compound containing a cinnamoyl moiety （PCPC） and a typically cholesteric liquid crystal cholesteryl cinnamate （CC） were synthesized to explore the mechanism ofcinnamoyl compounds, and the chemical structures of photodimerization were confirmed by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectral analysis. The photoreaction behaviors of these two cinnamoyl compounds in mesomorphic state and solution were investigated, UV-Vis spectral analysis was used to analyze the photoproduct. The results show that the photochemistry of PCPC in nematic state involves both photodimerization and photoisomerization, while CC shows a complex reaction which can be divided into three parts, and this has enabled us to present new data and interpretations regarding the [2＋2] photocycloaddition reaction. Additionally, the results of UV-Vis spectral analysis in solutions strongly suggest that UV-Vis spectral analysis can be used to study the kinetic behaviors of cinnamoyl moiety photoreaction.
文摘Fulgide 1-E doped in polystyrene polymer films was heated at various annealing temperatures.Upon irradiation with UV light(366 nm),fulgide 1-E undergoes a conrotatory ring closure to the pink colored closed form 1-C.The later color was switched back to the original color when the films were irradiated with white light.The kinetics of photocoloration and photobleaching processes were followed spectrophotometrically by monitoring the absorbance of the ring closed product 1-C at itsλ_(max) of 525 nm.The first-...
文摘Drug-induced phototoxicity is elicited by exposure of skin and/or eyes to topical or systemic administration of chemicals,followed by exposure to sunlight.For photosafety testing,a new screening strategy,employing in vitro photochemical/photobiological and in vivo cassette-dosing pharmacokinetic(PK)studies,was proposed[1,2].The screening system provided reliable phototoxic predictions of tested chemicals at least within the same chemical series;however,the applicability of the proposed strategy is not fully understood.
文摘Organic matters in drinking water of Kaschin-Beck disease areas were extracted. Then analyses and characterization were performed by means of multiply chemical and physical methods. The results did not show the obvious difference in the frame structure of humic substances and the structure of rmcromolecular compounds in the drinking water of disease and non-disease areas, but the difference in the contents of some micromolecular compounds and radicals. The investigation also includes the preliminary research on the photoreaction of drinking water from disease and non-disease areas and the accumulation of natural organic matter in the bone of tested animals.
文摘Photochemical reactions of 3-methylindole,carbazole,benzimidazole with fused polycyclic aromatic hydrocarbons in solid state were investigated,The structures of 4 new compounds were confirmed by IR,UV,\+1HNNR,MS and elemental analysis.The structure of compounds 3.6 was established by X-ray crystallography.
基金supported by the Science and Technology Development Foundation of Higher Education of Shanxi Province,China (No.200611042)
文摘We investigate theoretically the temperature effects on the evolutions of both bright and dark screening spatial solitons in biased two-photon photorefractive crystals.For a stable bright or dark two-photon screening spatial soliton originally formed in a crystal at a given temperature,when the crystal temperature changes,it will evolve into another stable screening soliton if the temperature change is quite small,while it will become unstable or break down if the temperature change is large enough.The spatial shape of a stable two-photon screening spatial soliton can be changed by appropriately adjusting the crystal temperature.
基金The project was supported by the Science and Technology Department of Henan Province (0624270041)
文摘The synthesis of syn-photodimer from 1,4-dihydropyridine without 4-aryl was studied, and its single crystal was obtained （C22H30N2O8, Mr= 450.48）. It crystallizes in monoclinic, space group P21/c with a = 11.937（2）, b = 20.913（4）, c = 9.763（2） A,β = 108.46（3）°, V= 2311.9（8） ,A^3, Z= 4, Dc = 1.294 g/cm^3,/7（000） = 960,μ = 0.099 mm^- 1, R = 0.0640 and wR = 0.1464 for 4077 unique reflections with 1598 observed ones （I 〉 2σ（I）. It is shown that the whole molecular structure of the title compound is a twist-boat conformation, and the two double bonds have a trend of potential intramolecular reaction under high-energy irradiation.
基金Supported by the National Natural Science Foundation of China(No.20904007)
文摘The density functional theory（DFT） calculations were performed to investigate a typical Norrish/Yang type II photoreaction of 5-methylbicyclo[1.1.1]-pentanyl ketone.The results reveal the essential correlation between structures on the one hand and energies,on the other hand,of the reactants,transition states and products based on both singlet ground（S0） and triplet excited（T1） potential energy surfaces.The feasible mechanism indicates that an intramolecular Norrish/Yang cyclization reaction takes place via H-abstraction to obtain the sole chiral cyclobutanol photoproduct.The located crossing point plays an important role in the cyclization process,which permits intersystem crossing（ISC） from T1 to S0 state.The rate-determining step may be to experience ISC between two different potential energy surfaces,requiring sufficient time for electron spin reversion,i.e.,spin multiplicity alteration.These conclusions are further confirmed by the second-order M ller-Plesset perturbation theory（MP2） calculations.
基金supported by the National Natural Science Foundation of China(22176058)the Science and Technology Commission of Shanghai Municipality(24DX1400200,23ZR1416100,25ZR1401082)+1 种基金the Program of Introducing Talents of Discipline to Universities(B16017)the Fundamental Research Funds for the Central Universities(222201717003)。
文摘Controllable photoreaction transition of photosensitizers(PSs)provides a highly promising approach for achieving efficient photodynamic therapy(PDT).However,tumor microenvironment-triggered phototransition remains a significant challenge and has not yet been reported.In this work,we develop a hydrogen bond self-assembly(HBSA)strategy that is triggered by the acidic tumor microenvironment to enable the photodynamic transition of tetra(4-carboxylphenyl)porphyrin(TCPP)PSs from type Ⅱ to type Ⅰ reactions.Upon self-assembly of TCPP monomers into TCPP assemblies(TCPP-ass),the generated reactive oxygen species shift from singlet oxygen to superoxide anions,which induces caspase-3/GSDME-mediated programmed pyroptosis,enabling rapid and complete solid tumor elimination with minimized adverse effects and enhanced therapeutic efficacy.Crucially,the HBSA process occurs exclusively within tumor cells,and this tumor-specific self-assembly strategy not only utilizes high tissue penetration of TCPP molecular-PSs,but also avoids phototoxicity caused by the formation and accumulation of TCPP-ass nano-PSs in normal tissue,providing an innovative approach for precise cancer therapy.
基金supported by the Key Research and Development Project of Hubei Province(no.2020BBB068)the Nature Science Foundation of Hubei Province(no.2020CFB400 and no.2021CFB218)+1 种基金the Central Committee Guides Local Science and Technology Development Special Project of Hubei Province(no.2019ZYYD059)the National Natural Science Foundation of China(no.52102111).
文摘Graphitic carbon nitride(g-C_(3)N_(4))nanosheets exfoliated from their bulk-sized counterparts are limited by a quantum size effect-induced widened bandgap.In this work,an(NH_(4))_(2)S_(2)O_(8)(APS)induced thermal exfoliation approach is introduced to fabricate O-doped g-C_(3)N_(4)nanosheets(OCNs).During this calcination process,the thermal decomposition products(NH_(3)and H_(2)SO_(4))from APS not only efficiently promote delamination,but also introduce O doping into the g-C_(3)N_(4)structure,realizing the synchronization control of the electronic structure and morphology.
基金supported by the National Natural Science Foundation of China(21201068)the Major Projects of Natural Science Research in Universities of Jiangsu Province(20KJA150002)+2 种基金the Natural Science Research Program of Huaian Science and Technology Bureau(HAB202156)the Huaishang Talent Program of Huaian,the Open Project of Key Laboratory for Chemistry of Low-Dimensional Materials in Universities of Jiangsu Province(Grant JSKC24027)the Excellent Scientific and Technological Innovation Team of Advanced Energy Materials Chemistry in Universities of Jiangsu Province and the Innovative Training Program for College Students.
文摘Photoreactive coordination polymers are important platforms for the implementation of tailored solidstate photochemical reactions.These crystalline compounds can also be employed as photo-controlled intelligent materials for the design and manufacture of advanced devices.Herein,a comb-like photoreactive coordination polymer,formulated as{[Zn(5-Cl-1,3-bdc)(H_(2)O)(2,3-ppe)]·H_(2)O}_(n)(1),was prepared based on the hydrothermal reaction between Zn(NO_(3))2·6H_(2)O,5-chlorobenzene-1,3-dicarboxylic acid(5-Cl-1,3-H_(2)BDC)and 1-(2-pyridyl)-2-(3-pyridyl)-ethylene(2,3-ppe).Upon irradiation with sunlight,the 1H NMR spectroscopy,UV-vis absorption spectroscopy and single crystal X-ray diffraction analyses results indicated that 1 can undergo a[^(2+)2]photocycloaddition reaction and thus generate a unique ladder-like coordination chain{[Zn(5-Cl-1,3-bdc)(H_(2)O)(2,3-bpbpcb)_(0.5)]·H_(2)O}n(1a,2,3-bpbpcb=1,3-bis(2-pyridyl)-2,4-bis(3-pyridyl)cyclobutane)via single-crystal to single-crystal(SCSC)transformation.Upon irradiation of UV light with a wavelength of 254 nm,the newly formed coordination chain 1a can undergo a reversible cycloreversion reaction and return to 1.The reversible photo-controllable cycloaddition-cycloreversion reaction between 1 and 1a also exhibits an interesting behavior of photo-switchable fluorescence.The reversible structural transformation and fluorescence switching behavior of 1 make it a potential photo-controlled intelligent material for optical information storage,optical anti-counterfeiting,fluorescence sensors and other fields.
基金the German Science Foundation(DFG)for funding though SPP2102.Computational time from the ZIH Dresden is gratefully acknowledged.We like to thank Prof.D.M.Guldi(Friedrich-Alexander-Universiteat Erlangen-Nuernberg)and his group for their support during the singlet oxygen phosphorescence measurements.
文摘The application of supramolecular host–vip chemistry for controlled photoreactivity and molecular sensing is a highly important field of modern inorganic and physical chemistry.One key aspect is the formation of the triplet state after photoexcitation.Applications of zinc ion Schiff-base derivatives for this purpose are rarely reported in the literature and there is still a lack of investigation into the triplet state formation of these supramolecular complexes.
基金supported by the National Natural Science Foundation of China(grant no.22322502)the National Key R&D Program of China(grant no.2023YFB3609000)the Natural Science Foundation of Shanghai(grant nos.22ZR1405800 and 23ZR1405100).
文摘Developing fully fusedπ-conjugated molecules with characteristic self-assembly and selective host–vip interaction by a wet chemistry approach remains very challenging.A series of fully fused thiophene-benzene alternating ribbons,BDTh-nT(n=2–6),have been successfully synthesized.X-ray crystallography analysis indicates that BDTh-nT adopt nearly planar configurations,with sulfur atoms oriented regularly in theπ-conjugated skeleton.With the increase ofπ-conjugated length,the ability of self-assembly shows a trend of increasing while the host–vip binding between BDTh-nT and spherical vip C_(60)exhibits obvious selectivity.Only BDTh-4T with appropriateπ-conjugated length can be combined with the spherical vip C_(60)by shape recognition.In addition,it is worth noting that BDTh-nT show a conjugated-length-dependent photoreactivity,in which BDTh-4/5/6T can achieve a fluorescence transition from blue-violet to light yellow/blue-white/orange-yellow under the excitation of 365 nm ultraviolet light.Our investigations will not only shed light on the supramolecular chemistry but also provide a strategy for design and precise synthesis of thienoacenes with desirable properties.
文摘1 Results Absolute asymmetric synthesis by means of solid-state reaction of chiral crystals self-assembled from achiral molecules is an attractive and promising methodology for asymmetric synthesis because it is not necessary to employ any external chiral source like a chiral catalyst.In order to design reliably absolute asymmetric syntheses in the solid state,it is inevitable to prepare and predict the formation of chiral crystals from achiral compounds.We have prepared a number of chiral cocrystals co...
