Spin-crossover(SCO)materials that reversibly switch between high-and low-spin states have potential for the storage of spin state-relative information,and have gained much attention incorporating secondary physical pr...Spin-crossover(SCO)materials that reversibly switch between high-and low-spin states have potential for the storage of spin state-relative information,and have gained much attention incorporating secondary physical properties,such as fluorescence and magneto-optical switching.In this study,we synthesized three octanuclear metal-organic cages(MOCs)using tetraphenylethylene-based luminophores,aldehydes,and Fe^(Ⅱ)salts,by subcomponent self-assembly approach,namely[Fe1]-[Fe3].By controlling the ligand-field strength and guest encapsulation,we finely tuned their SCO properties.Among them,MOC[Fe2]displayed nearly complete SCO behavior in the solid state,which is rare for high-nuclearity complexes.We also demonstrated the coupling of SCO with fluorescence emission in these MOCs by using isostructural Zn^(Ⅱ)complexes([Zn1]-[Zn3])as control experiments,for the first time.Theoretical calculations revealed the energy-transfer mechanism between fluorophores and SCOactive centers,which emphasizes the significant contribution of d-d transitions in the interplay between the occurrence of SCO and fluorescence emission.展开更多
In natural and artificial systems,reversible reactions are commonly asymmetric with respect to the time scale and nature of the stimuli which drive the forward and backward processes.In applications for which switchin...In natural and artificial systems,reversible reactions are commonly asymmetric with respect to the time scale and nature of the stimuli which drive the forward and backward processes.In applications for which switching behavior is required,it is desirable that the reversible reaction goes as close to symmetric as possible;however,such systems are uncommon.Herein,we report an example of ultraviolet(UV)-visible light-regulated asymmetric reversible structural switching involving a diene-based coordination polymer,CP1 and its monocyclobutane product,CP1a.It is possible to cycle at least ten times through a forward [2+2] photocycloaddition reaction and the reverse,photocleavage reaction.A single cycle can be completed within a few minutes.The transformation is accompanied by fast and distinct fluorescence changes,arising from optimisation of the reaction conditions.Density functional theory calculations allow rationalisation of the asymmetric reversible transformation between CP1 and CP1a rather than between CP1 and its dicyclobutane product CP1b.This work provides a clear illustration of reversible structural switching which approaches symmetric behaviour with respect to reaction rate and stimuli.The insights gained from this work also assist in the design of fast,reversible switching materials.展开更多
This paper reported the synthesis of hexaar- ylbiimidazole-tetraphenylethene （HABI-TPE） conjugated photochromic fluorophore, which simultaneously exhib- ited photochromic property, condensed state enhanced emission ...This paper reported the synthesis of hexaar- ylbiimidazole-tetraphenylethene （HABI-TPE） conjugated photochromic fluorophore, which simultaneously exhib- ited photochromic property, condensed state enhanced emission and reversible fluorescence switching. Upon UV irradiation, a green species with a broad absorption band between 550 and 800 nm（ the absorption maximum at 697 nm ） was observed, which readily faded to colorless in the darkness. HABI-TPE launched strong fluorescence with the maximum emission wavelength at 520 580 nm under the excitation with 450-500 nm visible light in condensed state, which is in contrast to nonfluorescence in solution. The maximum emission wavelength in condensed state was dependent of excitation wavelength. More interest- ingly, HABI-TPE exhibited reversible fluorescence switch- ing upon alternating irradiation with blue or near-UV light （wavelength less than 490 nm） and green light （more than 490 nm） in condensed state. Our evaluation demonstrated that HABI-TPE exhibited great photoswitchable fluores- cence, which is a promising photoswitchable fluorophore for localization-based super-resolution microscopy, evi- dencing by resolving nanostructures with sub-100nm resolution in polymethylmethacrylate films.展开更多
In this work, the absorption, fluorescence spectra, and fluorescence decay curve of Nd：Lu3Al5O12, i.e., neodym- ium lutetium aluminum garnet （Nd：LuAG） ceramic are investigated. A diode-end-pumped Nd：LuAG ceramic ...In this work, the absorption, fluorescence spectra, and fluorescence decay curve of Nd：Lu3Al5O12, i.e., neodym- ium lutetium aluminum garnet （Nd：LuAG） ceramic are investigated. A diode-end-pumped Nd：LuAG ceramic laser is demonstrated for the first time （to our knowledge）. We present the experiment results of Nd：LuAG ceramics continuous wave （CW） and electro-optically （E-O） Q-switched performance. CW output power of 2.5 W is obtained, corresponding to optical-to-optical efficiency of 17.2% and slope efficiency of 24.3%. For the E-O Q-switched setup, the shortest pulse width and the largest pulse energy are measm-ed to be 4.8 ns and 1.96 mJ, respectively. Its optical-to-optical efficiency and the slope efficiency are 17.3% and 28.7%, respectively.展开更多
To realize highly selective relay recognition of Fe3＋ and H2PO4^- ions, a simple benzimidazole-based fluorescent chemosensor （L） was designed and synthesized. Sensor L displays rapid, highly selective, and sensitiv...To realize highly selective relay recognition of Fe3＋ and H2PO4^- ions, a simple benzimidazole-based fluorescent chemosensor （L） was designed and synthesized. Sensor L displays rapid, highly selective, and sensitive recognition to Fe^3＋ in H2O/DMSO （1：1, v/v） solutions. The in stitu-generated L-Fe^3＋ complex solution exhibits a fast response and high selectivity toward dihydrogen phosphate anion via the Fe^3＋ displacement approach. The detection limits of sensor L to Fe^3＋ and L-Fe^3＋complex to H2PO4 anion were estimated to be 1.0 × 10^-9 mol/L. Notably, the sensor was retrievable to indicate dihydrogen phosphate an- ions with Fe^3＋, and HePO4 , in turn, increased. This successive recognition feature of sensor L makes it a potential utility for Fe^3＋ and H2PO4 anion detection in aqueous media.展开更多
基金supported by the National Natural Science Foundation of China(92061106,22101021,22071009)the Ministry of Science and Higher Education of the Russian Federation(State assignment in the field of scientific activity,project No.FENW-2023-0017)。
文摘Spin-crossover(SCO)materials that reversibly switch between high-and low-spin states have potential for the storage of spin state-relative information,and have gained much attention incorporating secondary physical properties,such as fluorescence and magneto-optical switching.In this study,we synthesized three octanuclear metal-organic cages(MOCs)using tetraphenylethylene-based luminophores,aldehydes,and Fe^(Ⅱ)salts,by subcomponent self-assembly approach,namely[Fe1]-[Fe3].By controlling the ligand-field strength and guest encapsulation,we finely tuned their SCO properties.Among them,MOC[Fe2]displayed nearly complete SCO behavior in the solid state,which is rare for high-nuclearity complexes.We also demonstrated the coupling of SCO with fluorescence emission in these MOCs by using isostructural Zn^(Ⅱ)complexes([Zn1]-[Zn3])as control experiments,for the first time.Theoretical calculations revealed the energy-transfer mechanism between fluorophores and SCOactive centers,which emphasizes the significant contribution of d-d transitions in the interplay between the occurrence of SCO and fluorescence emission.
基金supported by the National Natural Science Foundation of China (22271203)the State Key Laboratory of Organometallic Chemistry of Shanghai Institute of Organic Chemistry(KF2021005)+2 种基金the Collaborative Innovation Center of Suzhou Nano Science and Technologythe Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Project of Scientific and Technologic Infrastructure of Suzhou (SZS201905)。
文摘In natural and artificial systems,reversible reactions are commonly asymmetric with respect to the time scale and nature of the stimuli which drive the forward and backward processes.In applications for which switching behavior is required,it is desirable that the reversible reaction goes as close to symmetric as possible;however,such systems are uncommon.Herein,we report an example of ultraviolet(UV)-visible light-regulated asymmetric reversible structural switching involving a diene-based coordination polymer,CP1 and its monocyclobutane product,CP1a.It is possible to cycle at least ten times through a forward [2+2] photocycloaddition reaction and the reverse,photocleavage reaction.A single cycle can be completed within a few minutes.The transformation is accompanied by fast and distinct fluorescence changes,arising from optimisation of the reaction conditions.Density functional theory calculations allow rationalisation of the asymmetric reversible transformation between CP1 and CP1a rather than between CP1 and its dicyclobutane product CP1b.This work provides a clear illustration of reversible structural switching which approaches symmetric behaviour with respect to reaction rate and stimuli.The insights gained from this work also assist in the design of fast,reversible switching materials.
文摘This paper reported the synthesis of hexaar- ylbiimidazole-tetraphenylethene （HABI-TPE） conjugated photochromic fluorophore, which simultaneously exhib- ited photochromic property, condensed state enhanced emission and reversible fluorescence switching. Upon UV irradiation, a green species with a broad absorption band between 550 and 800 nm（ the absorption maximum at 697 nm ） was observed, which readily faded to colorless in the darkness. HABI-TPE launched strong fluorescence with the maximum emission wavelength at 520 580 nm under the excitation with 450-500 nm visible light in condensed state, which is in contrast to nonfluorescence in solution. The maximum emission wavelength in condensed state was dependent of excitation wavelength. More interest- ingly, HABI-TPE exhibited reversible fluorescence switch- ing upon alternating irradiation with blue or near-UV light （wavelength less than 490 nm） and green light （more than 490 nm） in condensed state. Our evaluation demonstrated that HABI-TPE exhibited great photoswitchable fluores- cence, which is a promising photoswitchable fluorophore for localization-based super-resolution microscopy, evi- dencing by resolving nanostructures with sub-100nm resolution in polymethylmethacrylate films.
文摘In this work, the absorption, fluorescence spectra, and fluorescence decay curve of Nd：Lu3Al5O12, i.e., neodym- ium lutetium aluminum garnet （Nd：LuAG） ceramic are investigated. A diode-end-pumped Nd：LuAG ceramic laser is demonstrated for the first time （to our knowledge）. We present the experiment results of Nd：LuAG ceramics continuous wave （CW） and electro-optically （E-O） Q-switched performance. CW output power of 2.5 W is obtained, corresponding to optical-to-optical efficiency of 17.2% and slope efficiency of 24.3%. For the E-O Q-switched setup, the shortest pulse width and the largest pulse energy are measm-ed to be 4.8 ns and 1.96 mJ, respectively. Its optical-to-optical efficiency and the slope efficiency are 17.3% and 28.7%, respectively.
基金supported by the National Natural Science Foundation of China(51203138,51273179,51573165,51406030)Natural Science Foundation of Zhejiang Province,China(LY15E030006,LY15E030002)+1 种基金Natural Science Foundation of Zhejiang University of Technology,China(1401101002408)Natural Science Foundation of Huzhou,China(2014YZ02)~~
基金supported by the National Natural Science Foundation of China(21064006,21161018,21262032)the Natural Science Foundation of Gansu Province(1010RJZA018)+1 种基金the Program for Changjiang ScholarsInnovative Research Teams in Universities of the Ministry of Education of China(IRT1177)
文摘To realize highly selective relay recognition of Fe3＋ and H2PO4^- ions, a simple benzimidazole-based fluorescent chemosensor （L） was designed and synthesized. Sensor L displays rapid, highly selective, and sensitive recognition to Fe^3＋ in H2O/DMSO （1：1, v/v） solutions. The in stitu-generated L-Fe^3＋ complex solution exhibits a fast response and high selectivity toward dihydrogen phosphate anion via the Fe^3＋ displacement approach. The detection limits of sensor L to Fe^3＋ and L-Fe^3＋complex to H2PO4 anion were estimated to be 1.0 × 10^-9 mol/L. Notably, the sensor was retrievable to indicate dihydrogen phosphate an- ions with Fe^3＋, and HePO4 , in turn, increased. This successive recognition feature of sensor L makes it a potential utility for Fe^3＋ and H2PO4 anion detection in aqueous media.
