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51.
The methyl carbonate of HOBt was developed for the conversion of alcohols to carbonates. This method is superior to the use of methyl chloroformate or methyl pyrocarbonate, especially with more hindered alcohols. The reagent is a stable solid that is easily prepared on a multigram scale. [reaction: see text] 相似文献
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Ataulla Shegiwal Alan M. Wemyss Mike A. J. Schellekens Jens de Bont James Town Evelina Liarou Georgios Patias Christophe J. Atkins David M. Haddleton 《Journal of polymer science. Part A, Polymer chemistry》2019,57(3):E1-E9
We present a systematic study of incorporating carboxyl groups into latex particles to enhance colloidal stability and the physical properties of the latex. Statistical copolymers of methacrylic acid and methyl methacrylate) were synthesized via catalytic chain transfer polymerization (CCTP) in emulsion. The vinyl‐terminated oligomers were in turn successfully utilized as chain transfer agents for the formation of diblock and pseudo triblock copolymers via sulfur‐free reversible addition–fragmentation chain transfer polymerization (SF‐RAFT). These copolymers were characterized using 1H NMR, size exclusion chromatography (SEC), dynamic light scattering (DLS), dynamic mechanical analysis (DMA), contact angle measurements and matrix‐assisted laser desorption/ionization time of flight mass spectroscopy (MALDI‐TOF‐MS) techniques. © 2019 The Authors. Journal of Polymer Science Part A: Polymer Chemistry published by Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, E1–E9 相似文献
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Mark T. Krejchi Edward D. T. Atkins Maurille J. Fournier Thomas L. Mason David A. Tirrell 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):1389-1398
Abstract A genetically engineered periodic polypeptide consisting of 36 repeats of the octapeptide sequence -(AlaGly)3GluGly- has been crystallized from solution in aqueous lithium bromide. Analysis by solid-state nuclear magnetic resonance spectroscopy, vibrational spectroscopy, and wide-angle x-ray diffraction reveals a crystal structure analogous to that obtained when silk solutions are allowed to dry under quiescent conditions, i.e., the silk I structure. Previous analyses of the same polymer have demonstrated an antiparallel β-sheet architecture (silk II structure) in samples crystallized from formic acid. These results illustrate the potential for controlling the solid-state structures and properties of genetically engineered materials through selection of appropriate processing and crystallization conditions. 相似文献
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[structure: see text] Single enantiomer, chiral donor-acceptor metal complexes were synthesized via the self-discriminating zinc(II) complexation of a pseudoracemic mixture of donor/acceptor-substituted bisoxazoline derivatives. 相似文献
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Atkins JL Patel MB Cusumano Z Gokel GW 《Chemical communications (Cambridge, England)》2010,46(43):8166-8167
Hydraphile synthetic ion channels were found to enhance the cytotoxicity to E. coli and B. subtilis of erythromycin, kanamycin, rifampicin, and tetracycline when co-administered with the antibiotic at sublethal concentrations of channel. 相似文献
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The rate of interconversion of ortho and para hydrogen in a solution of paramagnetic ions is calculated. The rate depends on the correlation of the magnetic fields at the two protons, and this is calculated on the basis of a dipolar interaction modulated by rotational and translational motion of the molecule and the ion. The theory is applied to experimental data on conversion caused by lanthanon and transition metal ions, and is used to estimate the radii of first hydration spheres. 相似文献
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The decay of a classical hindered rotor over the whole domain of motion from almost free overall rotation to harmonic vibration in a well is examined. The decay is described by a modification of a projection operator formalism involving the separation of dynamical and lattice time scales, and depends on a canonical transformation into a hindered rotating frame that rotates and oscillates in accord with the unperturbed equation of motion of two coaxial dipoles. 相似文献