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Exploring the Molecular Structure of Imidazolium–Silica‐Based Nanoparticle Networks by Combining Solid‐State NMR Spectroscopy and First‐Principles Calculations 下载免费PDF全文
Dr. Marie‐Alexandra Neouze Martin Kronstein Dr. Marco Litschauer Dr. Michael Puchberger Dr. Cristina Coelho Prof. Christian Bonhomme Prof. Christel Gervais Dr. Frederik Tielens 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(46):15188-15196
A DFT‐based molecular model for imidazolium–silica‐based nanoparticle networks (INNs) is presented. The INNs were synthesized and characterized by using small‐angle X‐ray scattering (SAXS), NMR spectroscopy, and theoretical ab initio calculations. 11B and 31P HETCOR CP MAS experiments were recorded. Calculated 19F NMR spectroscopy results, combined with the calculated anion–imidazolium (IM) distances, predicted the IM chain density in the INN, which was also confirmed from thermogravimetric analysis/mass spectrometry results. The presence of water molecules trapped between the nanoparticles is also suggested. First considerations on possible π–π stacking between the IM rings are presented. The predicted electronic properties confirm the photoluminescence emissions in the correct spectral domain. 相似文献
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Alexandra Botz Yves Chenavier Jacques Pécaut Pascale Delangle Christelle Gateau 《Tetrahedron letters》2018,59(26):2550-2553
The synthesis of several thiazonaphthalimide derivatives is described. The exclusive formation of angular rather than linear isomers was unequivocally demonstrated by NMR and single crystal X-ray diffraction. Their photophysical properties and ability to bind calf-Thymus DNA with affinities in the range of 104 makes them interesting candidates to probe DNA by fluorescence. 相似文献
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Belmessieri D Morrill LC Simal C Slawin AM Smith AD 《Journal of the American Chemical Society》2011,133(8):2714-2720
Tetramisole promotes the catalytic asymmetric intramolecular Michael addition-lactonization of a variety of enone acids, giving carbo- and heterocyclic products with high diastereo- and enantiocontrol (up to 99:1 dr, up to 99% ee) that are readily derivatized to afford functionalized indene and dihydrobenzofuran carboxylates. Chiral isothioureas also promote the catalytic asymmetric intermolecular Michael addition-lactonization of arylacetic acids and α-keto-β,γ-unsaturated esters, giving anti-dihydropyranones with high diastereo- and enantiocontrol (up to 98:2 dr, up to 99% ee). 相似文献
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Kiryutin AS Morozova OB Kuhn LT Yurkovskaya AV Hore PJ 《The journal of physical chemistry. B》2007,111(38):11221-11227
Relative values of the 1H and 13C isotropic hyperfine couplings in the cationic oxidized tryptophan radical TrpH*+ in aqueous solution are determined. The data are obtained from the photo-CIDNP (chemically induced dynamic nuclear polarization) enhancements observed in the microsecond time-resolved NMR spectra of the diamagnetic products of photochemical reactions in which TrpH*+ is a transient intermediate. The method is validated using the tyrosyl neutral radical Tyr*, whose 1H and 13C hyperfine couplings have previously been determined by electron paramagnetic resonance spectroscopy. Good agreement is found with hyperfine coupling constants for TrpH*+ calculated using density functional theory methods but only if water molecules are explicitly included in the calculation. 相似文献
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