French-Ukrainian Journal of Chemistry
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Ionic Liquids: from Neoteric Solvents to New Materials
Get PDFWe are glad and proud to present this special issue of the French Ukrainian Journal of Chemistry, dedicated to the chemistry of ionic liquids
First example of ring carbomer of 1,4-cyclohexadiene
Get PDFWhile a series of carbo-mers of 1,3-cyclohexadienes was reported through the use of a specifically developed synthetic strategy, no example of their 1,4-regioisomers was known. Inspired by the methodology elaborated for the preparation of the 1,3-isomers, the synthesis of the first example of carbo-mer of 1,4-cyclohexadiene is presented. Comparison of physico-chemical properties of this first representative with those of the recently described 1,4-regioisomer, especially UV-vis absorption properties, is also addressed
Complexation of Calix[4]arene bis-Hydroxymethylenediphosphonic Acid with Amino acids. Binding Constants Determination by RP HPLC Method
No full textHost-Guest complexation of calixarene-bis-hydroxymethylenediphosphonic acid with 17 amino acids in water solution had been studied by the RP HPLC and molecular modelling methods. It had been shown the binding constants of the complexes are depended on the nature of the amino acid residue, log P and pKa of the acids. The complexation is mainly determined by the electrostatic interactions between the positively charged nitrogen atom of the amino acid and the negatively charged oxygen atom of phosphonic acid residue of the calixarene, the Host-Guest p-p, СН-p and solvophobic interactions
Advances in chemistry of chromone aminomethyl derivatives
Get PDFChromones play an important role in the design and discovery of new pharmacologically active compounds. A large volume of reports dedicated to synthesis and study of properties of nitrogen-containing chromone derivatives show important role of chromone alkaloid-like compounds. The present review covers achievements in the field of synthesis of chromone aminomethyl derivatives as one of perspective scaffolds
Visual-test and Sorption-spectrophotometric Determination of Melamine in Biological Objects
Get PDFMelamine may have toxic effects on humans and animals. It is well known that melamine accumulates in the body and causes reproductive damages, forms bladder or kidney stones, which can lead to bladder cancer. Trace amounts of melamine at ppm levels may occur in certain food commodities due to its migration from melamine-containing disposable tableware plastics. It was intentionally adulterated to milk products to show a false increase in protein concentration. Considering these facts there is a need for establishing sensitive and reliable methods of melamine determination. As uncostly, rapid and selective melamine detection methods are highly required, the hyphenated sorption-spectrophotometric and visual test methods seem to be perspective candidates.In the present work the optimal conditions of sorption concentration of melamine from aqueous solutions ontо the silica gel surface were studied. The calibration graph for the sorption-spectrophotometric method is linear in 0.02 – 9.8 μmol.L-1 mg L-1 melamine concentration range. Proposed method allows naked-eye monitoring of biological samples.
Unexpected fragmentation of bis(triarylstannanethiocarbonyl)disulfides, formation and X-ray structure of triarylstannyl triarylstannanecarbodithioates
Get PDFThe synthesis of bis(triarylstannanethiocarbonyl)disulfides was attempted by oxidation of lithium triaryl stannane carbodithioates with molecular iodine. Unexpectedly,the desired compounds are highly unstable and undergo subsequent fragmentation giving triarylstannyl triarylstannanecarbodithioates. The proposed mechanism for this transformation assumes intramolecular nucleophilic substitution with formation of six-membered ring transition complex, stabilized by interaction between tin and thiocarbonyl sulfur atom. Obtained compounds were identified by mass-spectrometry and NMR spectroscopies, and their structures were analyzed by X-ray diffraction. These molecules show the existence of intramolecular non-bonding interactions between the sulfur atoms of the thiocarbonyl moieties and tin atoms. These interactions reflect the tin - sulfur affinity and are the main driving force in the fragmen tation of bis(triphenylstannanethiocarbonyl)disulfides. Supplementary information (CIF_file_1, CIF_file_2
On terminal alkynylcarbinols and derivatization thereof
Get PDFThe chemistry of three prototypes of secondary alkynylcarbinols (ACs), recently highlighted as challenging targets in anti-tumoral medicinal chemistry, is further documented by results on n-alkyl, alkynyl and alkenyl representatives. The N-naphthyl carbamate of an n-butyl-AC is thus characterized by X-ray crystallography. A novel dialkynylcarbinol (DAC) with synthetic potential is described, namely the highly dissymmetrical triisopropylsilyl-protected version of diethynylmethanol. The latter is shown to act as a dipolarophile in a selective Huisgen reaction with benzyl azide under CuAAC click conditions, giving an alkenyl-AC, where the alkene unsaturation is embedded in a 1,4-disubstituted 1,2,3-triazole ring, as confirmed by X-ray crystallography.Supplementary information (CIF file
Crystal structure of the Sr6Nb4ZrO18 slab perovskite-like compound
Get PDFThe Sr6Nb4ZrO18 niobatozirconate has been synthesized from the Sr5Nb4O15 four-layer perovskite and the SrZrO3 perovskite at T = 1670 K by ceramic technique. Crystal structure of the Sr6Nb4ZrO18 compound has been studied by the X-ray powder diffraction method. It was shown that crystal structure of the Sr6Nb4ZrO18 (a = 0.5687(1) nm, c = 4.146(1) nm, R-3m space group) belongs to the Ba6Nb4TiO18-type with five-layer perovskite-like structure. The crystal structure features of the Sr6Nb4BIVO18 compounds (BIV = Ti, Sn, Zr) has been analyzed. The correlation between composition and crystal structure features for all Sr6Nb4BIVO18 (BIV = Ti, Sn, Zr) compounds, which leads to destruction slab perovskite-like structure has been revealed
Synthesis and Investigation of Polymerization Properties of Methacrylic Monomers with Chiral Fragments
Get PDFMethacrylic monomers containing chiral moieties and azobenzene derivatives were synthesized. As the chiral component was used menthol. The polymerization properties of monomer (5-methyl-2- (1-methyl)cyclohexanol with azomonomers were studied and the reactivity ratios as well as parameters Q and e characterizing the activity of the obtained monomers have been calculated. On basis of the synthesized monomers were synthesized chiral-photochromic copolymers and their absorption spectra were studied. It was shown that in the copolymers absorption spectra the absorption maxima are in the wavelength region of 340-360 nm and correspond to trans-form of azo fragment
Catalytic Activity in CO Oxidation of MnOx Supported on Oxide and Zeolite Carriers
No full textCatalytic activity in CO oxidation was investigated for MnOx-containing materials, prepared by impregnation of SiO2, Al2O3 and zeolites (ZSM-5, ERI). The catalysts were characterized by temperature-programmed reduction (TPR) by hydrogen, diffuse-reflectance UV–Vis (DR UV–Vis) and infra-red (IR) spectroscopy of adsorbed CO. Effect of the previous treatment of the MnOx-containing systems on the catalytic performance has been established. Higher catalytic activity in CO oxidation of the materials treated with air as compared with treated with hydrogen can be explained by presences of manganese ions in +3 and +4 oxidation states. 3%Mn-SiO2 previously treated with air at 350 °C is found to be the most active catalyst among the studied ones. MnOx, CO oxidation, TPR, IR of adsorbed CO, DR UV–Vi