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- Gao, Lei, et al.
(author)
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Hydrophilic Cocrystals with Water Switched Luminescence
- 2024
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In: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773.
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Journal article (peer-reviewed)abstract
- Utilizing water molecules to regulate the luminescence properties of solid materials is highly challenging. Herein, we develop a strategy to produce water-triggered luminescence-switching cocrystals by coassembling hydrophilic donors with electron-deficient acceptors, where 1,2,4,5-Tetracyanobenzene (TCNB) was used as the electron acceptor and pyridyl benzimidazole derivatives were used as the electron donors enabling multiple hydrogen-bonds. Two cocrystals, namely 2PYTC and 4PYTC were obtained and showed heat-activated emission, and such emission could be quenched or weakened by adding water molecules. The cocrystal structure exhibited the donor molecule that can form multiple hydro bonds with water and acceptor molecules due to the many nitrogen atoms of them. The analyses of the photophysical data, powder X-ray diffraction, and other data confirmed the reversible fluorescence "on-off" effects were caused by eliminating and adding water molecules in the crystal lattice. The density functional theory calculations indicate that the vibration of the O-H bond of water molecules in the cocrystal can absorb the excitation energy and suppress fluorescence. Furthermore, the obtained cocrystals also showed temperature, humidity, and H+/NH4+ responsive emission behavior, which allows their applications as thermal and humidity sensors, and multiple information encryptions. This research paves the way for preparing intelligent hydrophilic organic cocrystal luminescent materials. Hydrophilic donors with electron-deficient acceptors were coassembled to achieve luminescence-switching cocrystals triggered by water molecules. The obtained cocrystals show a strong water absorption ability and excellent fluorescence properties. The emission of cocrystals can be reversibly switched by heating and water. Finally, the obtained cocrystals show potential applications in temperature-humidity and acid-base responses.+image
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3. |
- Gao, Lei, et al.
(author)
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Hydrophilic Cocrystals with Water Switched Luminescence
- 2024
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In: Angewandte Chemie International Edition. - : John Wiley & Sons. - 1433-7851 .- 1521-3773. ; 63:8
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Journal article (peer-reviewed)abstract
- Utilizing water molecules to regulate the luminescence properties of solid materials is highly challenging. Herein, we develop a strategy to produce water-triggered luminescence-switching cocrystals by coassembling hydrophilic donors with electron-deficient acceptors, where 1,2,4,5-Tetracyanobenzene (TCNB) was used as the electron acceptor and pyridyl benzimidazole derivatives were used as the electron donors enabling multiple hydrogen-bonds. Two cocrystals, namely 2PYTC and 4PYTC were obtained and showed heat-activated emission, and such emission could be quenched or weakened by adding water molecules. The cocrystal structure exhibited the donor molecule that can form multiple hydro bonds with water and acceptor molecules due to the many nitrogen atoms of them. The analyses of the photophysical data, powder X-ray diffraction, and other data confirmed the reversible fluorescence "on-off" effects were caused by eliminating and adding water molecules in the crystal lattice. The density functional theory calculations indicate that the vibration of the O-H bond of water molecules in the cocrystal can absorb the excitation energy and suppress fluorescence. Furthermore, the obtained cocrystals also showed temperature, humidity, and H+/NH4+ responsive emission behavior, which allows their applications as thermal and humidity sensors, and multiple information encryptions. This research paves the way for preparing intelligent hydrophilic organic cocrystal luminescent materials. Hydrophilic donors with electron-deficient acceptors were coassembled to achieve luminescence-switching cocrystals triggered by water molecules. The obtained cocrystals show a strong water absorption ability and excellent fluorescence properties. The emission of cocrystals can be reversibly switched by heating and water. Finally, the obtained cocrystals show potential applications in temperature-humidity and acid-base responses.+image
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- Tong, Danqing, et al.
(author)
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Achieving short-wavelength free radical emission by combining small conjugated structure and anti-Kasha emission
- 2023
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In: Dyes and pigments. - : ELSEVIER SCI LTD. - 0143-7208 .- 1873-3743. ; 219
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Journal article (peer-reviewed)abstract
- Since the natural narrow bandgaps of free radicals usually lead to emission in the long-wavelength region, it is still of great challenge to design radical luminescent materials with stable and short-wavelength emission in the ambient environment. In this work, a series of dicarbonyl-substituted organic molecules with small conjugated structures were used to form free radicals with short-wavelength radical emission. These low-conjugated mol-ecules with only one benzene ring showed stable photoinduced free radical emission after doping with poly-methyl methacrylate (PMMA) because the rigid polymer environment could help stabilize the free radicals and limit the non-radiative energy transfer. Moreover, PMMA with electron-withdrawing groups could promote the generation of carbonyl radical cations. The theoretical calculation suggests that the free radical with anti-Kasha emission derived from high energy excited state (D4 or D5) would directly relax to the ground state, combining with the small spin delocalization of the low conjugation free radical, leading to short-wavelength emission. More importantly, such free radical emissions could also respond to external stimulation such as light irradiation or heat treatment. These materials show great potential in lithography information recording and information encryption. This design strategy provides new insights into molecular and functional diversity of free radical materials.
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- Winbanks, Catherine E., et al.
(author)
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The bone morphogenetic protein axis is a positive regulator of skeletal muscle mass
- 2013
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In: Journal of Cell Biology. - : Rockefeller University Press. - 0021-9525 .- 1540-8140. ; 203:2, s. 345-357
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Journal article (peer-reviewed)abstract
- Although the canonical transforming growth factor. signaling pathway represses skeletal muscle growth and promotes muscle wasting, a role in muscle for the parallel bone morphogenetic protein (BMP) signaling pathway has not been defined. We report, for the first time, that the BMP pathway is a positive regulator of muscle mass. Increasing the expression of BMP7 or the activity of BMP receptors in muscles induced hypertrophy that was dependent on Smad1/5-mediated activation of mTOR signaling. In agreement, we observed that BMP signaling is augmented in models of muscle growth. Importantly, stimulation of BMP signaling is essential for conservation of muscle mass after disruption of the neuromuscular junction. Inhibiting the phosphorylation of Smad1/5 exacerbated denervation-induced muscle atrophy via an HDAC4-myogenin-dependent process, whereas increased BMP-Smad1/5 activity protected muscles from denervation- induced wasting. Our studies highlight a novel role for the BMP signaling pathway in promoting muscle growth and inhibiting muscle wasting, which may have significant implications for the development of therapeutics for neuromuscular disorders.
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- Zheng, Wei, et al.
(author)
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Bright Free-Radical Emission in Ionic Liquids
- 2023
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In: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773.
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Journal article (peer-reviewed)abstract
- It is challenging to achieve stable and efficient radical emissions under ambient conditions. Herein, we present a rational design strategy to protect photoinduced carbonyl free radical emission through electrostatic interaction and spin delocalization effects. The host-guest system is constructed from tricarbonyl-substituted benzene molecules and a series of imidazolium ionic liquids as the guest and host, respectively, whereby the carbonyl anion radical emission can be in situ generated under the light irradiation and further stabilized by electrostatic interaction. More importantly, the anion species and the alkyl chain length of imidazolium ionic liquids show a noticeable effect on luminescence efficiency, with the highest radical emission efficiency is as high as 53.3 % after optimizing the imidazole ionic liquids structure, which is about four times higher than the polymer-protected radical system. Theoretical calculations confirm the synergistic effect of strong electrostatic interactions and that the spin delocalization effect significantly stabilizes the radical emission. Moreover, such a radical emission system also could be integrated with a fluorescent dye to induce multi-color or even white light emission with reversible temperature-responsive characteristics. The radical emission system can also be used to detect different amine compounds on the basis of the emission changes and photoactivation time.
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