Hydrogels comprising anionic substituents in their polymer network were synthesized and adhered to each other following application of layered double hydroxides (LDHs) onto their surfaces. The resulting systems displayed high adhesive strength and tolerance for changes in parameters like solvent, salt concentration, and temperature. In experiments involving hydrogels with bulky anionic substituents, it was confirmed that the efficiency of the intercalation of the anionic groups into the layered inorganic compound LDH determines the strength of the adhesion. Moreover, intercalation-based adhesive joints connecting anionic hydrogels displayed higher tolerance for saline solutions than adhesive joints relying on electrostatic interactions between anionic and cationic hydrogels, even though, because of the electrostatic repulsion between charges with the same sign, one would expect that polymer networks comprising opposite charges would tolerate better the disruption caused by high saline concentration.
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http://dx.doi.org/10.1021/acsami.8b09136 | DOI Listing |
Org Lett
January 2025
College of Chemistry, Zhengzhou University, Zhengzhou, Henan 450001, China.
Herein, we report a method for the regioselective alkylation and phosphonation of quinoline C4-H via a BH-mediated nucleophilic addition of Turbo Grignard reagents and phosphine oxide anions to quinolines bearing different substituents, affording the 4-alkyl and 4-phosphoryl quinolines and tetrahydroquinolines after one-pot oxidation or reduction. The results indicate that coordination of the BH group can activate substrates toward a potential 1,4-dearomative addition and subtly control the regioselectivity by preventing the 1,2-dearomative addition.
View Article and Find Full Text PDFChemistry
December 2024
Université de Liège: Universite de Liege, Laboratory of Organometallic Chemistry and Homogeneous Catalysis, Institut de chimie B6a, Sart-Tilman, 4000, Liege, BELGIUM.
Thirteen imidazolium iodides bearing benzyl, mesityl, or 2,6-diiso-propyl-phenyl substituents on their nitrogen atoms, and C1 to C4 alkyl chains on their C2 carbon atom were readily deuterated with D2O as a cheap and non-toxic deuterium source in the presence of Cs2CO3, a weak, innocuous, inorganic base. The isotopic exchange proceeded quickly and efficiently under mild, aerobic conditions to afford a range of aNHC and NHO precursors regioselectively labeled on their C2α exocyclic position and/or C4=C5 heterocyclic backbone. A "carbene-free" mechanism was postulated, in which the carbonate anion acts as a catalyst to activate an exocyclic, acidic C-H bond and ease a deuterium transfer from D2O to the imidazolium salt in a concerted fashion.
View Article and Find Full Text PDFChemSusChem
December 2024
Tokyo Institute of Technology, Department of Chemical Science and Engineering, 4259 G1-9, Nagatsuta, Midori-ku,, 226-8501, Yokohama, JAPAN.
To realize the robust anion exchange membrane (AEM)-based water splitting modules and fuel cells, the design and synthesis of tetraarylphosphonium (TAP) cations are described as a new class of cationic building blocks that exhibit remarkable alkaline stability under harsh conditions. TAP cations with highly sterically demanding aromatic substituents were efficiently synthesized from triarylphosphine derivatives and highly reactive arynes, whose alkaline degradation proved to be suppressed dramatically by the sterically demanding substituents. In the case of bis(2,5-dimethylphenyl)bis(2,4,6-trimethylphenyl)phosphonium, for example, approximately 60% of the cation survived for 27 d under the forced conditions (i.
View Article and Find Full Text PDFJ Chromatogr A
January 2025
Restek Corporation, 110 Benner Circle, Bellefonte, PA, 16823, USA. Electronic address:
The chemical structure of nine imidazolium sulfonate and triflimide zwitterionic liquids (ZILs) were systematically tuned to increase their thermal stability for gas chromatography (GC) separations. Substituents for imidazolium and 2-phenylimidazolium cation systems, comprised of alkyl, benzyl, and oligoether groups of varying chain lengths, were studied as stationary phases in GC. Propanesulfonate, ethanesulfonate, and propanetriflimide anions were examined to understand the effect of linker length and nucleophilicity on ZIL thermal stability.
View Article and Find Full Text PDFJ Org Chem
December 2024
Department of Organic Chemistry and Biochemistry, Rud̵er Bošković Institute, Bijenička Cesta 54, Zagreb 10 000, Croatia.
BODIPY photocages (photocleavable protective groups) have stirred interest because they can release biologically active cargo upon visible light excitation. We conducted combined theoretical and experimental investigations on selected BODIPY photocages to elucidate the mechanism of the competing photocleavage at the boron and -position. Based on the computations, the former reaction involves elongation of the B-C bond, yielding a tight borenium cation and methyl anion.
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