The dynamic kinetic resolution of C-N atropisomeric pyridones was achieved asymmetric phase-transfer catalysis, exploiting a rotational barrier-lowering hydrogen bond in the starting materials. X-ray and NMR experiments revealed the presence of a barrier-raising ground state CH⋯π interaction in the product, supported by DFT calculations. A co-crystal of the quinidine-derived phase-transfer catalyst and substrate reveals key substrate-catalyst non-covalent interactions.
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http://dx.doi.org/10.1039/d2ob00177b | DOI Listing |
Chaos
January 2025
Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
Spirals are a special class of excitable waves that have its significance in the understanding of cardiac arrests and neuronal transduction. In a theoretical model of the chemical Belousov-Zhabotinsky reaction system, we explore the dynamics of the spatiotemporal patterns that emerge out of competing reaction and diffusion phenomena. By modifying the existing mathematical models of the reaction kinetics, we have been able to explore the explicit effect of hydrogen ion concentration in the system, so as to achieve various regimes of wave activity, from stable spirals to oscillation death.
View Article and Find Full Text PDFActa Bioeng Biomech
September 2024
Xinjiang University, China.
: The purpose of this study was to investigate dynamic responses of Lenke1B+ spines of adolescent scoliosis patients to different frequencies. : Modal analysis, harmonic response analysis and transient dynamics of a full spine model inverted by the finite element method using Abaqus. : The first-order axial resonance frequency of 4.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Zhejiang University, Key Laboratory of Biomass Chemical Engineering of the Ministry of Education, College of Chemical and Biological Engineering, 866 Yuhangtang Road, Xihu District, hangzhou City, 310058, Hangzhou, CHINA.
The separation of xylene isomers is a critical and energy-intensive process in the petrochemical industry, primarily due to their closely similar molecular structures and boiling points. In this work, we report the synthesis and application of a novel core-shell zeolitic imidazolate framework (ZIF) composite, ZIF-65@ZIF-67, designed to significantly enhance the kinetic separation of xylene isomers through a synergistic "shell-gated diffusion and core-facilitated transport" strategy. The external ZIF-67 shell selectively restricts the diffusion of larger isomers (MX and OX), while the internal ZIF-65 core accelerates the diffusion of PX, thereby amplifying the diffusion differences among the isomers.
View Article and Find Full Text PDFNanomicro Lett
January 2025
Shanghai Key Lab of Chemical Assessment and Sustainability, School of Chemical Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China.
Compared with Zn, the current mainly reported charge carrier for zinc hybrid capacitors, small-hydrated-sized and light-weight NH is expected as a better one to mediate cathodic interfacial electrochemical behaviors, yet has not been unraveled. Here we propose an NH-modulated cationic solvation strategy to optimize cathodic spatial charge distribution and achieve dynamic Zn/NH co-storage for boosting Zinc hybrid capacitors. Owing to the hierarchical cationic solvated structure in hybrid Zn(CFSO)-NHCFSO electrolyte, high-reactive Zn and small-hydrate-sized NH(HO) induce cathodic interfacial Helmholtz plane reconfiguration, thus effectively enhancing the spatial charge density to activate 20% capacity enhancement.
View Article and Find Full Text PDFSoft Matter
January 2025
Department of Physics, Central University of Karnataka, Kadaganchi, Kalaburagi, Karnataka-585367, India.
The isomerization kinetics of a liquid crystalline azobenzene dimer, comprising cyanoazobenzene and naphthalene (NAZ6), were investigated at the air-water interface. The Langmuir monolayers of NAZ6 in both its and states were analyzed using surface manometry techniques. The results revealed that NAZ6 molecules in the -state displayed the coexistence of a disordered liquid-expanded phase and an ordered liquid-condensed phase, whereas no such phase transition was observed in the -state.
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