In the present work, excited state intramolecular proton transfer(ESIPT) emission properties of a new benzotriazole derivative 4-formyl-2-(2H-benzotriazol-2-yl)-phenol(C1) were studied. 4-Formyl-2-(2H-benzotriazol-2-y...In the present work, excited state intramolecular proton transfer(ESIPT) emission properties of a new benzotriazole derivative 4-formyl-2-(2H-benzotriazol-2-yl)-phenol(C1) were studied. 4-Formyl-2-(2H-benzotriazol-2-yl)-methoxy-benzene(C2), 4-formyl-2-(2H-benzotriazol-2-yl)-phenyl acetate(C3) and 4-methyl-2-(2H-benzotriazol-2-yl)-phenol(C4) were used as the reference molecules.1H NMR chemical shift of hydroxy group in C1 was located at more down field than that of C4 or p-hydroxy-benzaldehyde(C5), respectively. C1 showed two absorption bands in the range of 260–400 nm zones in various solvents, while C2 and C3 exhibited single absorption band. The equal molar mixtures of C2/C5 or C3/C5 showed single absorption band.C2 and C3 displayed single fluorescence emission band in various solvents, while C1 exhibited dual emission bands in some strong polar solvents. Furthermore, the second emission band in these strong polar solvents showed the large Stokes shift. The results show that the second emission band of C1 was produced by ESIPT. C2 and C3 could not undergo ESIPT due to no hydroxy group. The geometry optimization calculation of enol and keto forms in the ground and excited states of C1 provided tough theoretical evidences of ESIPT.展开更多
The excited state intramolecular proton transfer of four derivatives(FM, BFM, BFBC, CCM) of 3-hydroxychromone is investigated.The geometries of different substituents are optimized to study the substituent effects on ...The excited state intramolecular proton transfer of four derivatives(FM, BFM, BFBC, CCM) of 3-hydroxychromone is investigated.The geometries of different substituents are optimized to study the substituent effects on proton transfer.The mechanism of hydrogen bond enhancement is qualitatively elucidated by comparing the infrared spectra, the reduced density gradient, and the frontier molecular orbitals.The calculated electronic spectra are consistent with the experimental results.To quantify the proton transfer, the potential energy curves(PECs) of the four derivatives in S0 and S1 states are scanned.It is concluded that the ability of proton transfer follows the order: FM > BFM > BFBC > CCM.展开更多
We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonometh...We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonomethyl)-naphthalene-2-ol and 1-pyrenecarboxaldehyde. Especially, the density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods for HNP monomer are introduced. Moreover, the "our own n-layered integrated molecular orbital and molecular mechanics"(ONIOM) method(TDDFT:universal force field(UFF)) is used to reveal the aggregation-induced emission(AIE) effect on the ESIPT process for HNP in crystal. Our results confirm that the ESIPT process happens upon the photoexcitation for the HNP monomer and HNP in crystal, which is distinctly monitored by the optimized geometric structures and the potential energy curves. In addition, the results of potential energy curves reveal that the ESIPT process in HNP will be promoted by the AIE effect. Furthermore, the highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) for the HNP monomer and HNP in crystal have been calculated. The calculation demonstrates that the electron density decrease of proton donor caused by excitation promotes the ESIPT process. In addition, we find that the variation of atomic dipole moment corrected Hirshfeld population(ADCH) charge for proton acceptor induced by the AIE effect facilitates the ESIPT process. The results will be expected to deepen the understanding of ESIPT dynamics for luminophore under the AIE effect and provide insight into future design of high-efficient AIE compounds.展开更多
该文使用4-乙酰氨基苯甲醛和碳酸肼一步法合成了一种具有聚集诱导荧光(AIE)特性的高效新型荧光探针1。通过荧光发射光谱、紫外光谱、粒度粒径分析、扫描电子显微镜和DFT理论计算讨论了探针1的AIE特性,证明了探针的发光机理是激发态分子...该文使用4-乙酰氨基苯甲醛和碳酸肼一步法合成了一种具有聚集诱导荧光(AIE)特性的高效新型荧光探针1。通过荧光发射光谱、紫外光谱、粒度粒径分析、扫描电子显微镜和DFT理论计算讨论了探针1的AIE特性,证明了探针的发光机理是激发态分子内质子转移(ESIPT)效应。探针1在DMSO-H_(2)O(1∶9,体积比),p H 7.4(PBS,0.2 mol/L)体系中可定量检测0~25μmol/L范围内的H_(2)S,检出限为0.27μmol/L。此外,探针1不仅成功用于实际样品中H_(2)S的检测,还可应用于活He La细胞中外源性H_(2)S的荧光成像。并将其用于构建超灵敏逻辑门。利用探针1制备的简单便携经济的检测试纸,能够实时有效地视觉检测H_(2)S。该研究有望为各种生理过程和食品样品中H_(2)S的检测提供可靠有效的新思路与新方法。展开更多
The simpler, the better! A series of simple and highly fluorescent salicylaldehyde hydrazide molecules （41 samples） have been designed and prepared. Even though these soft materials contain a very small π-conjugate...The simpler, the better! A series of simple and highly fluorescent salicylaldehyde hydrazide molecules （41 samples） have been designed and prepared. Even though these soft materials contain a very small π-conjugated system, they can go through multiple intramolecular and intermolecular hydrogen bonds promoted excited-state intramolecular proton-transfer （ESIPT） to display strong blue, green, yellow, and orange aggregation-induced emission （ALE） with large Stokes shifts （up to 184 nm） and high fluorescence quantum yields （φ up to 0.20）. Unusual mechanochromic fluorescence en- hancements are also found in some solid samples. Through coordination, hydrogen and halogen bonds, these flexible molecules can be used as Mg2＋ （φ up to 0.46） probes, universal anion （φ up to 0.14） and unprotected amino acids （φ up to 0.16） probes, and chiral diamine （enantiomeric selectivity and φ up to 0.36 and 0.062, respectively） receptors. Combining their advantages of AlE and biocompatibility, these low cytotoxic dyes have potential application in living cell imaging. Furthermore, the effects of different functional groups on the molecule arrangement, ESIPT, AlE, probe, and chiral recognition properties are also examined, which provide a simple and bright paradigm for the design of multiple-stimuli-responsive smart materials.展开更多
基金supported by Chongqing Natural Science Foundation(CSTC2012jj B50007,CSTC2010BB0216)the National Natural Science Foundation of China(21376282)+2 种基金F.Gao thanks the supporting from the Program for New Century Excellent Talents(NCET-10-0876)the Fundamental Research Funds for the Central Universities(CDJZR10220006)Y.Lu thanks the Graduate Innovation Foundation of Chongqing University(CDJXS11131146)
文摘In the present work, excited state intramolecular proton transfer(ESIPT) emission properties of a new benzotriazole derivative 4-formyl-2-(2H-benzotriazol-2-yl)-phenol(C1) were studied. 4-Formyl-2-(2H-benzotriazol-2-yl)-methoxy-benzene(C2), 4-formyl-2-(2H-benzotriazol-2-yl)-phenyl acetate(C3) and 4-methyl-2-(2H-benzotriazol-2-yl)-phenol(C4) were used as the reference molecules.1H NMR chemical shift of hydroxy group in C1 was located at more down field than that of C4 or p-hydroxy-benzaldehyde(C5), respectively. C1 showed two absorption bands in the range of 260–400 nm zones in various solvents, while C2 and C3 exhibited single absorption band. The equal molar mixtures of C2/C5 or C3/C5 showed single absorption band.C2 and C3 displayed single fluorescence emission band in various solvents, while C1 exhibited dual emission bands in some strong polar solvents. Furthermore, the second emission band in these strong polar solvents showed the large Stokes shift. The results show that the second emission band of C1 was produced by ESIPT. C2 and C3 could not undergo ESIPT due to no hydroxy group. The geometry optimization calculation of enol and keto forms in the ground and excited states of C1 provided tough theoretical evidences of ESIPT.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11874241,11847224,and 11804195)the Shandong Province Higher Educational Science and Technology Program,China(Grant No.J15LJ03)+1 种基金the Taishan Scholar Project of Shandong Province,China,China Post-Doctoral Foundation(Grant No.2018M630796)the Natural Science Foundation of Shandong Province,China(Grant No.ZR2018BA034)
文摘The excited state intramolecular proton transfer of four derivatives(FM, BFM, BFBC, CCM) of 3-hydroxychromone is investigated.The geometries of different substituents are optimized to study the substituent effects on proton transfer.The mechanism of hydrogen bond enhancement is qualitatively elucidated by comparing the infrared spectra, the reduced density gradient, and the frontier molecular orbitals.The calculated electronic spectra are consistent with the experimental results.To quantify the proton transfer, the potential energy curves(PECs) of the four derivatives in S0 and S1 states are scanned.It is concluded that the ability of proton transfer follows the order: FM > BFM > BFBC > CCM.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11574115 and 11704146)
文摘We theoretically investigate the excited state intramolecular proton transfer(ESIPT) behavior of the novel fluorophore bis-imine derivative molecule HNP which was designed based on the intersection of 1-(hydrazonomethyl)-naphthalene-2-ol and 1-pyrenecarboxaldehyde. Especially, the density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods for HNP monomer are introduced. Moreover, the "our own n-layered integrated molecular orbital and molecular mechanics"(ONIOM) method(TDDFT:universal force field(UFF)) is used to reveal the aggregation-induced emission(AIE) effect on the ESIPT process for HNP in crystal. Our results confirm that the ESIPT process happens upon the photoexcitation for the HNP monomer and HNP in crystal, which is distinctly monitored by the optimized geometric structures and the potential energy curves. In addition, the results of potential energy curves reveal that the ESIPT process in HNP will be promoted by the AIE effect. Furthermore, the highest occupied molecular orbital(HOMO) and lowest unoccupied molecular orbital(LUMO) for the HNP monomer and HNP in crystal have been calculated. The calculation demonstrates that the electron density decrease of proton donor caused by excitation promotes the ESIPT process. In addition, we find that the variation of atomic dipole moment corrected Hirshfeld population(ADCH) charge for proton acceptor induced by the AIE effect facilitates the ESIPT process. The results will be expected to deepen the understanding of ESIPT dynamics for luminophore under the AIE effect and provide insight into future design of high-efficient AIE compounds.
文摘该文使用4-乙酰氨基苯甲醛和碳酸肼一步法合成了一种具有聚集诱导荧光(AIE)特性的高效新型荧光探针1。通过荧光发射光谱、紫外光谱、粒度粒径分析、扫描电子显微镜和DFT理论计算讨论了探针1的AIE特性,证明了探针的发光机理是激发态分子内质子转移(ESIPT)效应。探针1在DMSO-H_(2)O(1∶9,体积比),p H 7.4(PBS,0.2 mol/L)体系中可定量检测0~25μmol/L范围内的H_(2)S,检出限为0.27μmol/L。此外,探针1不仅成功用于实际样品中H_(2)S的检测,还可应用于活He La细胞中外源性H_(2)S的荧光成像。并将其用于构建超灵敏逻辑门。利用探针1制备的简单便携经济的检测试纸,能够实时有效地视觉检测H_(2)S。该研究有望为各种生理过程和食品样品中H_(2)S的检测提供可靠有效的新思路与新方法。
基金This work was supported by the National Natural Science Foundation of China （No. 21372169） and Sichuan Provincial Foundation （2008SG0021）. We acknowledge the comprehensive training platform of the specialized laboratory of the College of Chemistry, Sichuan University, for material analysis. We acknowledge the comprehensive training platform of the specialized laboratory of the College of Chemistry, Sichuan University, for material analysis. We would like to thank the Analytical ＆ Testing Center of Sichuan University for CCD X-ray single crystal diffractometer work and circular dichroism CD spectrometer work. We are grateful to Daibing Luo and Yani Xie for help with the single crystal and circular dichroism measurements.
文摘The simpler, the better! A series of simple and highly fluorescent salicylaldehyde hydrazide molecules （41 samples） have been designed and prepared. Even though these soft materials contain a very small π-conjugated system, they can go through multiple intramolecular and intermolecular hydrogen bonds promoted excited-state intramolecular proton-transfer （ESIPT） to display strong blue, green, yellow, and orange aggregation-induced emission （ALE） with large Stokes shifts （up to 184 nm） and high fluorescence quantum yields （φ up to 0.20）. Unusual mechanochromic fluorescence en- hancements are also found in some solid samples. Through coordination, hydrogen and halogen bonds, these flexible molecules can be used as Mg2＋ （φ up to 0.46） probes, universal anion （φ up to 0.14） and unprotected amino acids （φ up to 0.16） probes, and chiral diamine （enantiomeric selectivity and φ up to 0.36 and 0.062, respectively） receptors. Combining their advantages of AlE and biocompatibility, these low cytotoxic dyes have potential application in living cell imaging. Furthermore, the effects of different functional groups on the molecule arrangement, ESIPT, AlE, probe, and chiral recognition properties are also examined, which provide a simple and bright paradigm for the design of multiple-stimuli-responsive smart materials.
