The excited-state intramolecular proton transfer process in 3-hydroxyflavone is investigated based on the computed structural parameters and energetics of stationary points of vibronically coupled S-S potential energy surfaces. A conical intersection close to the Franck-Condon point on S is identified. The minimum energy of the conical intersection is found to be near-degenerate with the equilibrium minimum of S. Quantum nuclear wavepacket simulations revealed a small population transfer from the "bright" S to "dark" S on a time scale shorter than the O-H stretching vibrational period. Such a nonadiabatic transition opens up the possibility of new photophysical and photochemical pathways, including the proton transfer via S.
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http://dx.doi.org/10.1063/1.5127271 | DOI Listing |
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January 2025
Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, Delhi, 110016, India.
Crystalline γ-FeO(OH) dominantly possessing ─OH terminals (𝛾-FeO(OH)), polycrystalline γ-FeO(OH) containing multiple ─O, ─OH, and Fe terminals (𝛾-FeO(OH)), and α-FeO majorly containing ─O surface terminals are used as electrocatalysts to study the effect of surface terminals on electrocatalytic nitrate reduction reaction (eNORR) selectivity and stabilization of reaction intermediates. Brunauer-Emmett-Teller analysis and electrochemically determined surface area suggest a high active surface area of 117.79 m g (ECSA: 0.
View Article and Find Full Text PDFAlzheimers Res Ther
January 2025
Radiology Department, Second Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong, China.
Background: The imbalance of glutamate (Glu) and gamma-aminobutyric acid (GABA) neurotransmitter system plays a crucial role in the pathogenesis of Alzheimer's disease (AD). Riluzole is a Glu modulator originally approved for amyotrophic lateral sclerosis that has shown potential neuroprotective effects in various neurodegenerative disorders. However, whether riluzole can improve Glu and GABA homeostasis in AD brain and its related mechanism of action remain unknown.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Environmental Analytical Chemistry, Helmholtz Centre for Environmental Research (UFZ), 04318, Leipzig, Germany.
Nanoplastics are suspected to pollute every environment on Earth, including very remote areas reached via atmospheric transport. We approached the challenge of measuring environmental nanoplastics by combining high-sensitivity TD-PTR-MS (thermal desorption-proton transfer reaction-mass spectrometry) with trained mountaineers sampling high-altitude glaciers ("citizen science"). Particles < 1 μm were analysed for common polymers (polyethylene, polyethylene terephthalate, polypropylene, polyvinyl chloride, polystyrene and tire wear particles), revealing nanoplastic concentrations ranging 2-80 ng mL at five of 14 sites.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Wuhan University, College of Chemistry and Molecular Sciences, Luojiashan Street, 430072, Wuhan, CHINA.
"Cell factory" strategy based on microbial anabolism pathways offers an intriguing alternative to relieve the dependence on fossil fuels, which are recognized as the main sources of CO2 emission. Typically, anabolism of intracellular substance in cell factory requires the consumption of sufficient reduced nicotinamide adenine dinucleotide phosphate (NADPH) and adenosine triphosphate (ATP). However, it is of great challenge to modify the natural limited anabolism and to increase the insufficient level of NADPH and ATP to optimum concentrations without causing metabolic imbalance.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
Materials Chemistry Research Center, Department of Chemistry, Faculty of Science, Khon Kaen University, Khon Kaen 40002 Thailand. Electronic address:
A zinc(II) coordination polymer, [Zn(Hdhtp)(2,2'-bpy)(HO)] (1), has been utilized as a dual-mode luminescence-colorimetric sensor (Hdhtp = 2,5-dihydroxy terephthalate and 2,2'-bpy = 2,2'-bipyridine). The presence of hydroxyl groups in Hdhtp can promote excited-state intra- and intermolecular proton transfer (ESIPT) phenomena. Therefore, compound 1, which displays high stability in aqueous environments, exhibits a strong green-yellow photoluminescence.
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