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101.
R. Kazimerczuk M. Borowiak K. Zwoliński A. Trzeciak J.Cz. Dobrowolski 《Tetrahedron letters》2007,48(39):7046-7048
Direct photocarbonylation of methane to give acetaldehyde occurred when a mixture of methane and CO dissolved in benzene was subjected to UV irradiation at λ < 290 nm. The reaction was accelerated by rhodium RhCl(CO)(PR3)2 complexes, where R = alkyl, Ph, or OPh. 相似文献
102.
103.
Sadlej-Sosnowska Nina Ocios-Bębenek Agnieszka Dobrowolski Jan Cz. Boczar Dariusz 《Structural chemistry》2022,33(2):479-490
Structural Chemistry - Cumulenes and polyynes have the potential to be applied as linear, sp-hybridized, one-dimensional all-carbon nanowires in molecular electronics and optoelectronics. The... 相似文献
104.
Amanda Grylewicz Kacper Szymaski Dominika Darowna Sylwia Mozia 《Molecules (Basel, Switzerland)》2021,26(9)
Ultrafiltration polyethersulfone (PES) membranes were prepared by wet phase inversion. Commercial halloysite nanotubes (HNTs) in the quantities of 0.5 wt% vs. PES (15 wt%) were introduced into the casting solution containing the polymer and different solvents: N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), or 1-methyl-2-pyrrolidinone (NMP). The type of solvent influenced the membranes’ morphology and topography, as well as permeability, separation characteristics, and antifouling and antibacterial properties. The membranes prepared using DMA exhibited the loosest cross-section structure with the thinnest skin and the roughest surface, while the densest and smoothest were the DMF-based membranes. The advanced contact angles were visibly lower in the case of the membranes prepared using DMF compared to the other solvents. The highest water permeability was observed for the DMA-based membranes, however, the most significant effect of the modification with HNTs was found for the NMP-based series. Regardless of the solvent, the introduction of HNTs resulted in an improvement of the separation properties of membranes. A noticeable enhancement of antifouling performance upon application of HNTs was found only in the case of DMF-based membranes. The study of the antibacterial properties showed that the increase in surface roughness had a positive effect on the inhibition of E. coli growth. 相似文献
105.
Renata Kasprzyk Beata J. Starek Sylwia Ciechanowicz Dorota Kubacka Joanna Kowalska Jacek Jemielity 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(27):6728-6740
The m7G cap is a unique nucleotide structure at the 5′-end of all eukaryotic mRNAs. The cap specifically interacts with numerous cellular proteins and participates in biological processes that are essential for cell growth and function. To provide small molecular probes to study important cap-recognizing proteins, we synthesized m7G nucleotides labeled with fluorescent tags via the terminal phosph(on)ate group and studied how their emission properties changed upon protein binding or enzymatic cleavage. Only the pyrene-labeled compounds behaved as sensitive turn-on probes. A pyrene-labeled m7GTP analogue showed up to eightfold enhanced fluorescence emission upon binding to eukaryotic translation initiation factor 4E (eIF4E) and over 30-fold enhancement upon cleavage by decapping scavenger (DcpS) enzyme. These observations served as the basis for developing binding- and hydrolytic-activity assays. The assay utility was validated with previously characterized libraries of eIF4E ligands and DcpS inhibitors. The DcpS assay was also applied to study hydrolytic activity and inhibition of endogenous enzyme in cytoplasmic extracts from HeLa and HEK cells. 相似文献
106.
Miriam M. Schwab Daniel Himmel Sylwia Kacprzak Daniel Kratzert Valentin Radtke Philippe Weis Kallol Ray Ernst‐Wilhelm Scheidt Wolfgang Scherer Bas deBruin Stefan Weber Ingo Krossing 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(49):14919-14922
The straightforward synthesis of the cationic, purely organometallic NiI salt [Ni(cod)2]+[Al(ORF)4]− was realized through a reaction between [Ni(cod)2] and Ag[Al(ORF)4] (cod=1,5‐cyclooctadiene). Crystal‐structure analysis and EPR, XANES, and cyclic voltammetry studies confirmed the presence of a homoleptic NiI olefin complex. Weak interactions between the metal center, the ligands, and the anion provide a good starting material for further cationic NiI complexes. 相似文献
107.
The synthesis of S-alkylated cysteine derivatives was carried out successfully in the presence of 1,1,3,3-tetramethylguanidine. Alkylation proceeded in high yields on unprotected amino acids and peptides containing a sulfhydryl group. 相似文献
108.
A. P. Mazurek J. Cz. Dobrowolski J. Sadlej E. Bednarek L. Kozerski 《Journal of Molecular Structure》2000,520(1-3):45-52
The piperazine and triethylamine complexes of genistein, exhibiting high immunosuppressant activity, were ab initio modeled at RHF/6-31G** level and results were compared with those obtained for genistein–morpholine complexes by X-ray, NMR, and theoretical methods. The most stable genistein–piperazine complex is formed due to hydrogen bonding of genistein's OH group at position C7 to piperazine's nitrogen atom. In the most stable genistein–triethylamine complex genistein's OH group at position C4′ (position para to phenyl substituent) and trimethylamine nitrogen atom are engaged in hydrogen bond formation. The calculations confirmed our previous NMR conclusion that piperazine is more strongly complexed by genistein than is morpholine or triethylamine. The theoretical 13C NMR spectra correlate fairly well with the experimental spectra. 相似文献
109.
Michael R. Martinez Sylwia Dworakowska Adam Gorczyński Grzegorz Szczepaniak Ferdinando De Luca Bossa Krzysztof Matyjaszewski 《Journal of polymer science. Part A, Polymer chemistry》2022,60(12):1887-1898
The photoinduced energy/electron transfer-reversible addition-fragmentation chain transfer (PET-RAFT) polymerizations of oligo(ethylene oxide) monomethyl ether methacrylate (OEOMA, also known as poly[ethylene glycol] methyl ether methacrylate, PEGMA) and isomeric methyl 2-(oligo(ethylene oxide) methyl ether)acrylate (2OEOAM) macromonomers with OEO average degree of polymerization of 22 or 45 were conducted in aqueous media to provide insight into the effect of monomer structure on grafting-through RAFT of 1,1-disubstituted acrylic macromonomers. The polymerizations of all four monomers reached nearly quantitative conversion. The longer macromonomers polymerized faster than the shorter ones within the same monomer class. The OEO side chain at the α (i.e., 2-) position of isomeric acrylates significantly slowed RAFT polymerization in comparison with OEO ester side chain of methacrylates. 相似文献
110.
An identity s = t is linear if each variable occurs at most once in each of the terms s and t. Let T be a tolerance relation of an algebra ${\mathcal{A}}$ in a variety defined by a set of linear identities. We prove that there exist an algebra ${\mathcal{B}}$ in the same variety and a congruence θ of ${\mathcal{B}}$ such that a homomorphism from ${\mathcal{B}}$ onto ${\mathcal{A}}$ maps θ onto T. 相似文献