32 research outputs found

    Supplementary_Table - Obstructive Sleep Apnea and Sleep Position: Does It Matter for Infants With a Cleft Palate?

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    Supplementary_Table for Obstructive Sleep Apnea and Sleep Position: Does It Matter for Infants With a Cleft Palate? by Christopher J. Greenlee, Melissa A. Scholes, Dexiang Gao, and Norman R. Friedman in The Cleft Palate-Craniofacial Journal</p

    Pressure-Induced Hydrogen Transfer in 2‑Butyne via a Double CH···π Aromatic Transition State

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    Hydrogen transfer (H-transfer) is an important elementary reaction in chemistry and bioscience. It is often facilitated by the hydrogen bonds between the H-donor and acceptor. Here, at room temperature and high pressure, we found that solid 2-butyne experienced a concerted two-in–two-out intermolecular CH···π H-transfer, which initiated the subsequent polymerization. Such double H-transfer goes through an aromatic Hückel six-membered ring intermediate state via intermolecular CH···π interactions enhanced by external pressure. Our work shows that H-transfer can occur via the CH···π route in appropriate conformations under high pressure, which gives important insights into the H-transfer in solid-state hydrocarbons

    From Biomass to Functional Crystalline Diamond Nanothread: Pressure-Induced Polymerization of 2,5-Furandicarboxylic Acid

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    2,5-Furandicarboxylic acid (FDCA) is one of the top-12 value-added chemicals from sugar. Besides the wide application in chemical industry, here we found that solid FDCA polymerized to form an atomic-scale ordered sp3-carbon nanothread (CNTh) upon compression. With the help of perfectly aligned π–π stacked molecules and strong intermolecular hydrogen bonds, crystalline poly-FDCA CNTh with uniform syn-configuration was obtained above 11 GPa, with the crystal structure determined by Rietveld refinement of the X-ray diffraction (XRD). The in situ XRD and theoretical simulation results show that the FDCA experienced continuous [4 + 2] Diels–Alder reactions along the stacking direction at the threshold C···C distance of ∼2.8 Å. Benefiting from the abundant carbonyl groups, the poly-FDCA shows a high specific capacity of 375 mAh g–1 as an anode material of a lithium battery with excellent Coulombic efficiency and rate performance. This is the first time a three-dimensional crystalline CNTh is obtained, and we demonstrated it is the hydrogen bonds that lead to the formation of the crystalline material with a unique configuration. It also provides a new method to move biomass compounds toward advanced functional carbon materials
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