检索结果-南通市图书馆

Chinese Journal of Chemical Physics 2022年第2期35卷 331-337,I0011-I0025,I0003页

作者： Hongling Zhang Qingtong Liu Yiying Wang Zhe Tang Panwang Zhou Institute of Molecular Sciences and Engineering Institute of Frontier and Interdisciplinary ScienceShandong UniversityQingdao 266237China state Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China

excited-state intramolecular proton transfer(ESIPT)is favored by researchers because of its unique optical ***,there are relatively few systematic studies on the effects of changing the electronegativity of atoms on the ESIPT process and photophysical ***,we selected a series of benzoxazole isothiocyanate fluorescent dyes(2-HOB,2-HSB,and 2-HSe B)by theoretical methods,and systematically studied the ESIPT process and photophysical properties by changing the electronegativity of chalcogen *** calculated bond angle,bond length,energy gap,and infrared spectrum analysis show that the order of the strength of intramolecular hydrogen bonding of the three molecules is 2-HOB2-HSB>2-HSe *** addition,the calculated electronic spectrum shows that as the atomic electronegativity decreases,the emission spectrum has a ***,this work will offer certain theoretical guidance for the synthesis and application of new dyes based on ESIPT properties.

关键词： excited-state intramolecular proton transfer Photophysical properties Energy barrier Electronegativity

Monitoring intracellular pH fluctuation with an excited-state intramolecular proton transfer-based ratiometric fluorescent sensor

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2021年第10期32卷 3057-3060页

作者： Bin Feng Yingli Zhu Jiaxin Wu Xueyan Huang Rong Song Liu Huang Xueping Feng Wenbin Zeng Xiangya School of Pharmaceutical Sciences Central South UniversityChangsha 410013China The Molecular Imaging Research Center Central South UniversityChangsha 410013China Hunan Key Laboratory of Diagnostic and Therapeutic Drug Research for Chronic Diseases Central South UniversityChangsha 410013China Xiangya Hospital Central South UniversityChangsha 410013China

Intracellular pH is a key parameter related to various biological and pathological *** this study,a ratiometric pH fluorescent sensor ABTT was developed harnessing the amino-type excited-state intramolecular proton transfer(ESIPT) *** on whether the ESIPT proceeds normally or not,ABTT exhibited the yellow fluorescence in acidic media,or cyan fluorescence in basic *** to the variation,ABTT behaved as a promising sensor which possessed fast and reversible response to pH change without interference from the biological substances,and exported a steady ratiometric signal(I_(478)/I_(546)).Moreover,due to the ESIPT effect,large Stokes shift and high quantum yield were also exhibited in ***,ABTT was applied for monitoring the pH changes in living cells and visualizing the pH fluctuations under oxidative stress *** results elucidated great potential of ABTT in understanding pH-dependent physiological and pathological processes.

关键词： excited-state intramolecular proton transfer Intracellular pH Sulfonamide Ratiometric sensor Fluorescent imaging

Deep-red and near-infrared organic lasers based on centrosymmetric molecules with excited-state intramolecular double proton transfer activity

在线全文

学校读者我要写书评

暂无评论

光电进展(英文) 2023年第7期6卷 19-28页

作者： Chang-Cun Yan Zong-Lu Che Wan-Ying Yang Xue-Dong Wang Liang-Sheng Liao Macao Institute of Materials Science and Engineering Macao University of Science and TechnologyTaipaMacao SAR 999078China Institute of Functional Nano&Soft Materials Jiangsu Key Laboratory for Carbon-Based Functional Materials&DevicesJoint International Research Laboratory of Carbon-Based Functional Materials and DevicesSoochow UniversitySuzhou 215123China Jiangsu Engineering Laboratory of Novel Functional Polymeric Materials Jiangsu Key Laboratory of Advanced Negative Carbon TechnologiesCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China.

Organic lasers that emit light in the deep-red and near-infrared(NIR)region are of essential importance in laser communication,night vision,bioimaging,and information-secured displays but are still challenging because of the lack of proper gain ***,a new molecular design strategy that operates by merging two excited-state intramolecular proton transfer-active molecules into one excited-state double proton transfer(ESDPT)-active molecule was *** on this new strategy,three new materials were designed and synthesized with two groups of intramolecular resonance-assisted hydrogen bonds,in which the ESDPT process was proven to proceed smoothly based on theoretical calculations and experimental results of steady-state and transient *** from the effective six-level system constructed by the ESDPT process,all newly designed materials showed low threshold laser emissions at approximately 720 nm when doped in PS microspheres,which in turn proved the existence of the second proton transfer *** importantly,our well-developed NIR organic lasers showed high laser stability,which can maintain high laser intensity after 12000 pulse lasing,which is essential in practical *** work provides a simple and effective method for the development of NIR organic gain materials and demonstrates the ESDPT mechanism for NIR lasing.

关键词： excited-state intramolecular proton transfer organic laser near-infrared emission molecular design

Computational Insights into the excited state intramolecular proton transfer Reactions in Ortho-hydroxylated Oxazolines

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2021年第5期40卷 540-548,527页

作者： LIU Gai-Mei MA Wei-Jia WANG Yan YANG Yan SONG Xin-Jian School of Chemistry and Environmental Engineering Hubei Minzu UniversityEnshi 445000China Key Laboratory of Magnetic Resonance in Biological Systems National Center for Magnetic Resonance in WuhanState Key Laboratory of Magnetic Resonance and Atomic and Molecular PhysicsWuhan Institute of Physics and MathematicsChinese Academy of SciencesWuhan 430071China

excited-state intramolecular proton transfer(ESIPT) reactions of three ortho-hydroxylated oxazolines, 2-(4,4-dimethyl-4,5-dihydro-oxazol-2-yl)-phenol(DDOP), 4-(4,4-dimethyl-4,5-dihydro-oxazol-2-yl)-[1,1?-biphenyl]-3-ol(DDOP-C_(6)H_(5)) and 4-(4,4-dimethyl-4,5-dihydrooxazol-2-yl)-3-hydroxy-benzonitrile(DDOP-CN), have been systematically explored by density functional theory(DFT) and time-dependent density functional theory(TDDFT) methods. Two stable configurations(enol and keto forms) are found in the ground states(S_(0)) for all the compounds while the enol form only exists in the first excited states(S_(1)) for the compound modified with electron donating group(-C_(6)H_(5)). In addition, the calculated absorption and emission spectra of the compounds are in good agreements with the experiments. Infrared vibrational spectra at the hydrogen bond groups demonstrate that the intramolecular hydrogen bond O(1)-H(2)···N(3) in DDOP-C_(6)H_(5) is strengthened in the S_(1) states, while the frontier molecular orbitals further reveal that the ESIPT reactions are more likely to occur in the S_(1) states for all the compounds. Besides, the proton transfer potential energy curves show that the enol forms can barely convert into keto forms in the S_(0) states because of the high energy barriers. Meanwhile, intramolecular proton transfer of all the compounds could occur in S_(1) states. The ESIPT reactions of the ortho-hydroxylated oxazolines are barrierless processes for unsubstituted DDOP and electron withdrawing substituted DDOP-CN, while the electron donating substituted DDOP-C_(6)H_(5) has a small barrier, so the electron donating is unfavorable to the ESIPT reactions of ortho-hydroxylated oxazolines.

关键词： excited-state intramolecular proton transfer electron donating group ortho-hydroxylated oxazolines potential energy curves

Near-infrared organic lasers with ultra-broad emission bands by simultaneously harnessing four-level and six-level systems

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第8期35卷 288-293页

作者： Lei Wang Jun-Jie Wu Chang-Cun Yan Wan-Ying Yang Zong-Lu Che Xin-Yu Xia Xue-Dong Wang Liang-Sheng Liao Jiangsu Key Laboratory for Carbon-Based Functional Materials&Devices Institute of Functional Nano&Soft Materials(FUNSOM)Soochow UniversitySuzhou 215123China Jiangsu Engineering Laboratory of Novel Functional Polymeric Materials College of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China Macao Institute of Materials Science and Engineering Macao University of Science and TechnologyMacao SAR 999078China

Organic lasers with broad emission bands in near-infrared(NIR)region are crucial for their applications in laser communication,night-vision as well as bioimaging owing to the abundance of selectable lasing ***,for most organic gain materials,gain regions are limited in a small wavelength range because of the fixed energy level ***,we design a strategy to realize NIR organic lasers with broad emission bands based on tunable energy level systems induced by cascaded excited-state intramolecular proton transfer(ESIPT).A novel gain material named DHNN was developed,which can undergo a cascaded double-ESIPT process supporting four-level and six-level systems *** doping DHNN into polystyrene microspheres,NIR lasers with tunable emission bands can be achieved based on the careful modulation of ***,organic lasers with an ultra-broad emission band ranging from 700 nm to 900 nm was successfully achieved by harnessing four-level and six-level systems simultaneously.

关键词： excited-state intramolecular proton transfer Organic solid-state laser Wide gain interval Near-infrared emission Molecular design

Tactfully revealing the working mechanisms on a tetraarylimidazole derivative:AIE characteristic,ESIPT process and ICT effect integrating in one molecule

在线全文

学校读者我要写书评

暂无评论

中国化学快报:英文版 2023年第8期34卷 392-397页

作者： Min Liu Shibo Zhong Bin Feng Yueming Ren Xiaohui Liu Shuaige Bai Fei Chen Shao Liu Wenbin Zeng Xiangya School of Pharmaceutical Sciences Central South UniversityChangsha 410013China Department of Pharmacy Xiangya HospitalCentral South UniversityChangsha 410008China National Clinical Research Center for Geriatric Disorders Xiangya HospitalCentral South UniversityChangsha 410008China

Recently,a novel tetraarylimidazole derivative 2-(benzo[d]thiazol-2-yl)-4-(4,5-bis(4-methoxyphenyl)-1-phenyl-1H-imidazol-2-yl)-phenol(be called MHBT herein)was architectured by our research group showing the fascinating synergy of aggregation-induced emission(AIE)characteristic,excited-state intramolecular proton transfer(ESIPT)mechanism and intramolecular charge transfer(ICT)***,a detailed and reasonable interpretation of its mechanisms both in theory is urgently ***,to unveil the working mechanism meticulously,herein,we tactfully applied density functional theory(DFT)and time-dependent density functional theory(TD-DFT)methods to illuminate the underlying mechanisms in different solvent *** optimizing the structures,the geometric parameters of hydrogen bonds(HBs),the infrared(IR)vibrational spectrum,the reduced density gradient(RDG)isosurfaces were calculated in detail,vividly explaining how the enhancement of HBs behaved as the driving force to proceed ESIPT ***,the frontier molecular orbitals(FMOs)combined with the potential energy curves(PECs)were conducted to interpretate the role and character of ICT and ESIPT in molecule ***,the PECs of MHBT for dihedral angles in different organic solvents were calculated to compare the dominant torsion degree,rationalizing the AIE phenomenon from the view of the restriction of intramolecular rotation *** work may well underpin the understanding of the interaction between different mechanisms in fluorescent dyes and thereby provide meaningful guideline for the design and construction of ideal molecules.

关键词： Tetraarylimidazole derivative Aggregation-induced emission excited-state intramolecular proton transfer intramolecular charge transfer Density functional theory Time-dependent density functional theory