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
An organic compound exhibiting simultaneously reversible switch between its emission colors and luminescence mechanisms,possessing high contrast from deep blue normal fluorescence(NF) to yellow thermally activated del...An organic compound exhibiting simultaneously reversible switch between its emission colors and luminescence mechanisms,possessing high contrast from deep blue normal fluorescence(NF) to yellow thermally activated delayed fluorescence(TADF),is reported. Based on these two complementary colors, white-light emission combining NF and TADF from a single compound can be achieved in various states. Experimental results and density functional theory calculations indicate that the controllable conformational distribution under thermal and mechanical activation is the mechanism responsible for the reversible switching behavior.展开更多
Photoactive cocrystal materials have received growing research interest in construction of photofunctional systems owing to the crucial roles in modifying the photo-related properties of molecular solids, based on the...Photoactive cocrystal materials have received growing research interest in construction of photofunctional systems owing to the crucial roles in modifying the photo-related properties of molecular solids, based on the non-bonding interactions between self-assembly units. Herein, we report tunable luminescence and acid-base stimuli-responsive properties of a cocrystal assembled by 4-[2-(4-quinolinyl)vinyl]phenol (qv) and tetrafluoroterephthalic acid (a). The luminescent properties (such as wavelength, quantum yield and fluorescence lifetime) of qv.a changed obviously relative to the pristine qv, due to the proton transfer and the alternation of molecular arrangement within two-component crystalline material. The photoemission intensity of qv.a underwent from weak to strong upon HCl gas fuming, and the corresponding wavelength changed from 517 nm to 597 nm, which can be reversibly transferred after exposed in NH3. Such luminescent switching behavior may provide an effective way to develop new types of photoactive stimuli-responsive materials and optical sensors.展开更多
Switching on/off single-molecule magnets(SMMs)at room temperature is still a challenge in moleculebased magnets.Herein,two photochromic Ln-based(Ln=Dy,Tb)phosphonate coordinated polymers were synthesized with regulabl...Switching on/off single-molecule magnets(SMMs)at room temperature is still a challenge in moleculebased magnets.Herein,two photochromic Ln-based(Ln=Dy,Tb)phosphonate coordinated polymers were synthesized with regulable SMM behavior.The reversible room-temperature photo-coloration was an electron transfer process with a generation of relatively stable radicals,characterized by structural analyses,ultraviolet-visible,luminescence and electron spin resonance spectra and magnetic measurements.Importantly,owing to the antiferromagnetic coupling interactions between Ln^(3+) ions and photogenerated radicals,the room-temperature light irradiation surprisingly switched off the SMM behavior,showing the first example of radicalquenched SMMs in the molecule-based magnets.Moreover,the silient SMM behavior could be recovered after eliminating photogenerated radicals via heat treatment,showing a reversible off/on switch of SMMs via light and heat.This work constructs a system for switching off/on SMMs through electron transfer photochromism,providing a visual operation way via naked-eye-detectable coloration for the switchable SMMs.展开更多
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.
基金supported by the National Key R&D Program of China (2016YFB0401004)the National Natural Science Foundation of China (51625301, 51573059, 91233116)+1 种基金the National Basic Research Program of China (2015CB655003)Guangdong Provincial Department of Science and Technology (2016B090906003, 2016TX03C175)
文摘An organic compound exhibiting simultaneously reversible switch between its emission colors and luminescence mechanisms,possessing high contrast from deep blue normal fluorescence(NF) to yellow thermally activated delayed fluorescence(TADF),is reported. Based on these two complementary colors, white-light emission combining NF and TADF from a single compound can be achieved in various states. Experimental results and density functional theory calculations indicate that the controllable conformational distribution under thermal and mechanical activation is the mechanism responsible for the reversible switching behavior.
基金supported by the National Natural Science Foundation of China (21301016, 21473013)the National Basic Research Program of China (2014CB932103)+2 种基金Beijing Municipal Natural Science Foundation (2152016)the Fundamental Research Funds for the Central UniversitiesAnalytical and Measurements Fund of Beijing Normal University
文摘Photoactive cocrystal materials have received growing research interest in construction of photofunctional systems owing to the crucial roles in modifying the photo-related properties of molecular solids, based on the non-bonding interactions between self-assembly units. Herein, we report tunable luminescence and acid-base stimuli-responsive properties of a cocrystal assembled by 4-[2-(4-quinolinyl)vinyl]phenol (qv) and tetrafluoroterephthalic acid (a). The luminescent properties (such as wavelength, quantum yield and fluorescence lifetime) of qv.a changed obviously relative to the pristine qv, due to the proton transfer and the alternation of molecular arrangement within two-component crystalline material. The photoemission intensity of qv.a underwent from weak to strong upon HCl gas fuming, and the corresponding wavelength changed from 517 nm to 597 nm, which can be reversibly transferred after exposed in NH3. Such luminescent switching behavior may provide an effective way to develop new types of photoactive stimuli-responsive materials and optical sensors.
基金supported by the National Natural Science Foundation of China(21901133,22171155 and 22071126)the State Key Laboratory of Fine Chemicals(KF1905)。
文摘Switching on/off single-molecule magnets(SMMs)at room temperature is still a challenge in moleculebased magnets.Herein,two photochromic Ln-based(Ln=Dy,Tb)phosphonate coordinated polymers were synthesized with regulable SMM behavior.The reversible room-temperature photo-coloration was an electron transfer process with a generation of relatively stable radicals,characterized by structural analyses,ultraviolet-visible,luminescence and electron spin resonance spectra and magnetic measurements.Importantly,owing to the antiferromagnetic coupling interactions between Ln^(3+) ions and photogenerated radicals,the room-temperature light irradiation surprisingly switched off the SMM behavior,showing the first example of radicalquenched SMMs in the molecule-based magnets.Moreover,the silient SMM behavior could be recovered after eliminating photogenerated radicals via heat treatment,showing a reversible off/on switch of SMMs via light and heat.This work constructs a system for switching off/on SMMs through electron transfer photochromism,providing a visual operation way via naked-eye-detectable coloration for the switchable SMMs.
