French-Ukrainian Journal of Chemistry
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Ionic liquids in catalysis: molecular and nanometric metal systems
Get PDFThe catalyst immobilization in a liquid phase represents an attractive means to preserve high activities and selectivities, also permitting an easy recycling. To attain this goal, organic products should be extracted in a simple way from the catalytic phase leading to metal-free target compounds; for this reason, ionic liquids exhibiting high affinity for metallic species and low affinity for low polar compounds, turn into a promising medium, in particular for the synthesis of fine chemicals. In the present Accounts, we illustrate this approach through our research involving both molecular organometallic compounds and metallic nanoparticles dispersed in an ionic liquid phase
The dynamic characteristics of polyurethane matrix of dye laser solid-state active elements
Get PDFInvestigations of polyurethane matrices for solid-state laser active elements showed that comparison of chain mobility and permeability for low molecular substances of polyurethanes based on glycol and diisocyanate components of various structures allows predict their radiation resistance and choose optimal chemical composition of polyurethane. The correlation was shown of polyurethane dynamic properties with values of their elastic modulus and laser damage threshold under pulsed laser irradiation as well as the weak influence of phenalenone dyes introduction on the above characteristics
Room-Temperature Zwitterionic Ionic Liquids
Get PDFA novel series of zwitterionic ionic liquids based on (E) or (Z) isomer of an urocanic moiety containing a carboxylate group have been prepared. All synthesized compounds present melting points below 100°C. This value can be easily tuned by changing the length of alkyl chain grafted on the imidazolium moiety and the nature of isomer. Hence, melting temperature as low as -20°C was obtained for Z isomer with a N1, N3-methyloctyl imidazolium moiety
Polymer-Analogous Transformations in Triblock Copolymers Containing Polyacrylamide and Poly(ethylene oxide)
Get PDFThe polymer-analogous conversion of triblock copolymers (TBC) PAAm-b-PEO-b-PAAm by the aminomethylation reaction in PAAm blocks under the effect of dimethylamine and formaldehyde (Mannich’s reaction) was studied. Kinetic investigations of the Mannich’s reaction in TBC as compared to that in pure PAAm were performed by potentiometric titration. The existence of two competitive polymer-analogous transformations in PAAm chains of all the (co)polymers such as aminomethylation and alkaline hydrolysis of amide groups was established and discussed
In situ polymerization of 4-(methacryloylamino) phenyl-2-methylacrylate on the surface of silicagel
Get PDFImmobilization of 4-(methacryloylamino)phenyl-2-methylacrylate homopolymer on the silica gel surface has been carried out in situ. The structure and quantitative characteristics of immobilized polymer have been examined by IR spectroscopy, thermogravimetric analysis and mass spectrometry. Adsorption activity towards microquantitatives of Pb(II), Cu (II), Mn(II), Co(II), Ni(II) and Fe(III) ions in the range of pH 6-8,5 has been observed. Quantitative adsorption of trace Pb(II) in neutral and slightly alkaline media has been reported
Preparation of IL-loaded microreactors based on polyelectrolyte microcapsules
Get PDFEncapsulation of ionic liquids (ILs) in crosslinked polyelectrolyte microcapsules, made via layer-by-layer assembly (LbL) was successfully conducted. Two different ILs were studied: 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim]BF4 and 1-butyl-3-methylimidazolium hexafluorophosphate [Bmim]PF6. The polyelectrolyte microcapsules were successfully used as microcages for the synthesis of poly(methylmethacrylate) (PMMA), a non water-soluble polymer, in IL medium. Finally, the behaviour of the IL-loaded microreactors in polar and apolar solvents was evaluated. The strategies described in this study offer new routes for the preparation of microreactors incorporating IL which are of interest for many applications in the field of organic synthesis, catalysis and adsorption of active substances. Supplementary informatio
Reaction of pyrido[2,1-a]isoindole with 1,4-naphtoquinone and study of the product by spectroscopic methods
Get PDFKey role of the electronic structure of condensed isoindols in the way of the rearrangement was shown. Influence of the dienophile manifests in the requirement of the cyclic form of the dienophile itself. In the reaction of pyrido[2,1-a]isoindole with naphtoquinone rearrangement product of the first type was obtained and its structure was proven by spectral methods. Spectral criteria for the rearranged adducts of the first type for the pyrido[2,1-a]isoindole in the 13C NMR spectra were established. Products of reactions with naphthoquinone, 4-fluoro-, 2,5-difluorophenylmaleimides were isolated and characterized: (2E)-2-[(1,4-dihydroxy-2-naphthyl)(2-pyridin-2-ylphenyl)methylene]-4-hydroxynaphthalen-1(2H)-one, (3E)-1-(4-fluorophenyl)-3-[[1-(4-fluorophenyl)-2,5-dioxopyrrolidin-3-yl](2-pyridin-2-ylphenyl)methylene]pyrrolidine-2,5-dione, (3E)-1-(2,4-difluorophenyl)-3-[[1-(2,4-fluorophenyl)-2,5-dioxopyrrolidin-3-yl](2-pyridin-2-ylphenyl)methylene]pyrrolidine-2,5-dione
Adjusting the cation and anion nature in ionic liquids used for the growth control of nanoparticles of organic conductors
Get PDFIonic liquids are used for controlling the growth of organic conductors as nanoparticles. We review the conditions of preparation of nanoparticles of conductors derived from tetrathiafulvalene (TTF), tetramethyltetraselenafulvalene (TMTSF) and bis-ethylenedithiotetrathiafulvalene (BEDT-TTF). They are prepared by electrocrystallization using an ionic liquid supporting electrolyte in which the cation plays the role of growth controller and the anion enters the composition of the expected organic conductor. Stable suspensions of nanoparticles are obtained in one case, a valuable characteristic for potential applications in electronic devices
New Ferrocene Derivatives for Ligand Grafting
No full textFive new 1,2-disubstituted ferrocene derivatives have been efficiently synthesized. These compounds contain one protected phosphine function as thiophosphine, another coordination site (nitrogen or oxygen atom) and a function ready for the grafting on various supports. All compounds have been and fully characterized by NMR(1H, 31P and 13C) and High Resolution Mass Spectroscopy. The molecular structure of three of these ferrocene derivatives have been determined by X ray diffraction analysis on monocrystals
Effect of imidazolinium salts bearing hydroxy substituents on palladium-catalysed Suzuki–Miyaura and Heck coupling reactions
Get PDFPalladium anionic complexes with imidazolinium cations containing hydroxyl substituents were used as catalyst precursors in the Suzuki–Miyaura and the Heck cross-coupling. High activity of anionic complexes was noted in the Suzuki–Miyaura reaction of 2-bromotoluene with phenylboronic acid at 40 oC in 2-propanol and a 2-propanol/water mixture using conventional heating or microwaves. Similarly, bromonaphtalene and iodonaphtalene reacted efficiently with naphtylboronic acid and 4-methylnaphtylboronic acid. A remarkably lower activity was noted when anionic palladium complexes were employed in the Heck coupling of 2,3-dihydrofuran with iodobenzene. An increase in conversion in the Heck reaction was achieved when Pd(OAc)2 was used as a catalyst precursor together with imidazolinium salts as co-catalysts