Ultraviolet photodissociation (UVPD) spectra of protonated 9-methyladenine (H9MA), protonated 7-methyl adenine (H7MA), protonated 3-methyladenine (H3MA), and sodiated 7-methyladenine (Na7MA) near the origin bands of the S-S transition were obtained using cryogenic ion spectroscopy. The UV-UV hole burning, infrared (IR) ion-dip, and IR-UV double resonance spectra showed that all the ions were present as single isomers in a cryogenic ion trap. The UVPD spectrum of H9MA exhibited only a broad absorption band, whereas the spectra of H7MA, H3MA, and Na7MA displayed moderately or well-resolved vibronic bands. Potential energy profiles were computed to understand the reason for the different bandwidths of the vibronic bands in the spectra. The broadening of the bands was correlated with the slopes between the Franck-Condon point and the conical intersection between the S and S states in the potential energy profiles, thus reflecting the deactivation rates in the S state.
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http://dx.doi.org/10.1021/acs.jpca.2c09083 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Ulsan National Institute of Science and Technology, Department of Chemistry, UNIST GIL 50, 44919, Ulsan, KOREA, REPUBLIC OF.
Efficient separation of hydrogen isotopes, especially deuterium (D2), is pivotal for advancing industries such as nuclear fusion, semiconductor processing, and metabolic imaging. Current technologies, including cryogenic distillation and Girdler sulfide processes, suffer from significant limitations in selectivity and cost-effectiveness. Herein, we introduce a novel approach utilizing an imidazolium-based Metal-Organic Framework (MOF), JCM-1, designed to enhance D2/H2 separation through temperature-dependent gate-opening controlled by ion exchange.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
School of Chemistry, Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, Beihang University, Beijing 100191, China.
Potassium (K)-based batteries hold great promise for cryogenic applications owing to the small Stokes radius and weak Lewis acidity of K. Nevertheless, energy-dense (>200 W h kg) K batteries under subzero conditions have seldom been reported. Here, an over 400 W h kg K battery is realized at -40 °C via an anode-free and dual-ion strategy, surpassing these state-of-the-art K batteries and even most Li/Na batteries at low temperatures (LTs).
View Article and Find Full Text PDFMicroscopy (Oxf)
December 2024
Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima-cho, Yokosuka, Kanagawa 237-0061, Japan.
It is challenging to image structures in liquids for electron microscopy (EM); thus, low-temperature imaging has been developed, initially for aqueous systems. Organic liquids (OLs) are widely used as dispersants, although their cryogenic EM (cryo-EM) imaging is less common than that of aqueous systems. This is because the basic properties (e.
View Article and Find Full Text PDFNature
January 2025
School of Environment and Energy, State Key Laboratory of Luminescent Materials and Devices, Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, South China University of Technology, Guangzhou, China.
Lithium (Li) metal batteries (LMBs) are promising for high-energy-density rechargeable batteries. However, Li dendrites formed by the reaction between highly active Li and non-aqueous electrolytes lead to safety concerns and rapid capacity decay. Developing a reliable solid-electrolyte interphase is critical for realizing high-rate and long-life LMBs, but remains technically challenging.
View Article and Find Full Text PDFSmall
January 2025
Department of Mechanical Engineering, University of Delaware, Newark, DE, 19716, USA.
Failure of the active particles is inherently electrochemo-mechanics dominated. This review comprehensively examines the electrochemo-mechanical degradation and failure mechanisms of active particles in high-energy density lithium-ion batteries. The study delves into the growth of passivating layers, such as the solid electrolyte interphase (SEI), and their impact on battery performance.
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