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Ab initio molecular dynamics calculations were used to explore the underlying factors that modulate the velocity of hydrogen migration for 1,2 hydrogen shifts in carbocations in which different groups interact noncovalently with the migrating hydrogen. Our results indicate that stronger electrostatic interactions between the migrating hydrogen and nearby π-systems lead to slower hydrogen migration, an effect tied to entropic contributions from the hydrogen + neighboring group substructures.
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http://dx.doi.org/10.1039/d0cp05000h | DOI Listing |
J Phys Chem A
September 2025
Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, United States.
Ionization of alkanes to form radical cations activates their otherwise unreactive C-H bonds, facilitating important chemical processes such as hydrocarbon cracking. This work investigates the radical cation dissociation dynamics of hexane (CH) structural isomers by using femtosecond time-resolved mass spectrometry and quantum chemical calculations. All five isomers exhibit competition between the yields of fragment ions arising from direct C-C bond cleavage or dissociative rearrangement with hydrogen migration on dynamical time scales of ∼50-300 fs, suggesting that hydrogen migration in the metastable cations operates on such short time scales.
View Article and Find Full Text PDFCarbohydr Polym
November 2025
College of Food Science, South China Agricultural University, Guangzhou 510642, China. Electronic address:
Sacha inchi shell extract (SISE), whose main active substance is a polysaccharide, has been reported to have hypotensive effects. Consequently, a novel acidic arabinogalactan, termed SISP, was isolated from SISE, and its efficacy in protecting vascular endothelial cells was investigated. SISP had a molecular weight of 57.
View Article and Find Full Text PDFCarbohydr Polym
November 2025
Key Lab of Guangdong Province for High Property and Functional Polymer Materials, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China. Electronic address:
Inspired by spider silk, polyphenolic nanodots (PTa) loaded multi-layer MXene (mMXene-PTa) through hydrogen and coordination bonds was prepared by self-polymerizing tannic acid on mMXene and used as a new crosslinker for polyvinyl alcohol (PVA). Together with starch (ST), mMXene-PTa was compounded with PVA and exfoliated to fabricate PVA/ST/mMXene-PTa nanocomposite. The phenolic hydroxyl groups in PTa formed high-density H-bonds with PVA and ST, creating an organic-inorganic dynamic crosslinking network with mMXene-PTa as nodes.
View Article and Find Full Text PDFMol Divers
September 2025
Department of General Practice, People's Hospital Affiliated to Chongqing Three Gorges Medical College, Chongqing Three Gorges Medical College, No. 27, Guoben Road, Wanzhou District, Chongqing, 404197, China.
Dendrobium officinale Kimura et Migo (DO) has demonstrated potential anti-colon adenocarcinoma (COAD) effects; however, its underlying mechanisms of action require further elucidation. In this study, DO (work concentrations of 0, 0.1, and 0.
View Article and Find Full Text PDFInt J Biol Macromol
September 2025
Department of Otorhinolaryngology Head and Neck Surgery, Guangzhou Twelfth People's Hospital (The Affiliated Twelfth People's Hospital of Guangzhou Medical University), Guangzhou Medical University, Guangzhou 510620, China. Electronic address:
Diabetic wound healing remains a critical clinical challenge due to persistent inflammation derived from long-term hyperglycemia. To address this challenge, we reported a zinc ion coordinated CMCS hydrogel for pH responsive delivery of ellagic acid to fulfill diabetic wound management. The incorporation of zinc ions and EA reinforce the hydrogel network via coordination and hydrogen bonding, and confer a pH-responsive release of EA under simulative wound microenvironment.
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