Mica substrates were activated by a plasma method leading to OH-functionalized surfaces to which an atom transfer radical polymerization (ATRP) radical initiator was covalently bound using standard siloxane protocols. The unprecedented covalently immobilized initiator underwent radical polymerization with tert-butyl acrylate, yielding for the first time end-grafted polymer brushes that are covalently linked to mica. The initiator grafting on the mica substrate was confirmed by time-of-flight secondary ion mass spectrometry (TOF-SIMS), while the change in the water contact angle of the OH-activated mica surface was used to follow the change in surface coverage of the initiator on the surface. The polymer brush and initiator film thicknesses relative to the virgin mica were confirmed by atomic force microscopy (AFM). This was done by comparing the atomic step-height difference between a protected area of freshly cleaved mica and a zone exposed to plasma activation, initiator immobilization, and then ATRP.
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http://dx.doi.org/10.1021/la703051b | DOI Listing |
Adv Mater
December 2024
National and Local Joint Engineering Research Center of MPTES in High Energy and Safety LIBs, Engineering Research Center of MTEES (Ministry of Education), and Key Lab. of ETESPG (GHEI), School of Chemistry, South China Normal University, Guangzhou, 510006, China.
The dehydrogenative cross-coupling reaction is the premier route for synthesizing important 4-quinazolinone drugs. However, it usually requires high reaction temperature and long reaction time, and the yield of the final product is low. Here two stable and photosensitive covalent-organic frameworks (COFs), TAPP-An and TAPP-Cu-An are purposefully designed and constructed to serve as unprecedented heterogeneous tandem catalysts to complete dehydrogenative cross-coupling reactions in a short time and under mild reaction conditions (room temperature and light), leading to the high-efficient photosynthesis of 4-quinazolinones.
View Article and Find Full Text PDFAcc Chem Res
December 2024
Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan.
ConspectusSelective chemical modification of endogenous proteins in living systems with synthetic small molecular probes is a central challenge in chemical biology. Such modification has a variety of applications important for biological and pharmaceutical research, including protein visualization, protein functionalization, proteome-wide profiling of enzyme activity, and irreversible inhibition of protein activity. Traditional chemistry for selective protein modification in cells largely relies on the high nucleophilicity of cysteine residues to ensure target-selectivity and site-specificity of modification.
View Article and Find Full Text PDFChem Sci
December 2024
School of Materials Science and Engineering, PCFM Lab, the Key Laboratory of Low-carbon Chemistry & Energy Conservation of Guangdong Province, Sun Yat-sen University Guangzhou 510006 P. R. China
Metal-ligand cooperation (MLC) is an essential strategy in transition metal catalysis. Traditional NH-based and OH-based MLC catalysts, as well as the later developed (de)aromatization strategy, have been widely applied in atom-economic borrowing hydrogen/hydrogen auto-transfer (BH/HA) reactions. However, these conventional MLC approaches are challenging for low-coordination and low-activity coinage metal complexes, arising from the instability during (de)protonation on the coordination atom, the constraint in linear coordination, and possible poisoning due to extra functional sites.
View Article and Find Full Text PDFChemistry
November 2024
Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustrasse 3, 14195, Berlin, Germany.
The self-assembly process is governed by the individual constituents of molecules through precise non-covalent interactions. Amphiphilic cyanines are intriguing in supramolecular chemistry due to the large polarizability of their delocalized π-electron systems, their tuneable optical properties and their ability to form well-defined self-assembled structures in different media. Here we present the synthesis of a novel tetrahydroxy amphiphilic carbocyanine dye with perfluoro alkylated chains -(CH)-(CF)-CF as hydrophobic segments and aminoproanediol as hydrophilic segment.
View Article and Find Full Text PDFChem Soc Rev
November 2024
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, Jilin University, Changchun 130012, P. R. China.
Covalent organic frameworks (COFs) represent a highly versatile class of crystalline porous materials, formed by the deliberate assembly of organic building units into ordered two-dimensional (2D) and three-dimensional (3D) structures. Their unique combination of topological precision and tunable micro- or mesoporous architectures offers unmatched flexibility in material design. By selecting specific building units, reactive sites, and functional groups, COFs can be engineered to achieve customized skeletal, porous, and interfacial properties, opening the door to materials with optimized performance for diverse applications.
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