Vol 65, No 11 (2016)

In the present review comparative data concerning various synthetic approaches and methodologies used in the series of ferrocene and cymantrene derivatives to create various materials, namely, catalytic systems, sensory and other molecular devices, polymers as well as physiologically active substances, for the period from 2000 till 2016 are given. Aspects of practical application of the above compounds are also considered.

Recent advances in the fields of application of the composites based on quantum dots (QDs) as optical converters for the light emitting devices, solar cells and biofunctional nanoprobes for detection of markers and medical diagnostics are considered. The possibilities of application of various QD—ligand—polymer combinations depending on desired photophysical properties in the final composite are analyzed. An attempt is made to predict the key future trends in the fabrication and application of hybrid nanocomposites for biomedicine and optoelectronics.

Thermodynamic characteristics of electrophilic substitution reactions of 1H-tetrazole and 2H-tetrazole proceeding by the elimination—addition scheme with F⁺, Cl⁺, and Br⁺ as model cations were compared using the results of DFT/B3LYP/6-31G(d,p) quantum chemical calculations carried out with inclusion of specific solvation effects. Possible reasons for lower reactivity (based on the results of calculations) of 2H-tetrazole compared to that of 1H-isomer are discussed.

A reaction of Sc, Y, and Yb amidopyridinate dichlorides with the corresponding amount of LiCH₂SiMe₃ was used to synthesize bis(trimethylsilylmethyl) complexes (Ap)Ln(CH₂SiMe₃)₂-(THF) (Ap is N-mesityl-6-(2,4,6-triisopropylphenyl)pyridine-2-amide (Ap^9Me), Ln = Y (2); Ap is N-(2,6-diisopropylphenyl)-6-(2,4,6-triisopropylphenyl)pyridine-2-amide (Ap*), Ln = Sc (3), Yb (4)). An exchange reaction of yttrium amidopyridinate dichloride derivative 1 with 4 equiv. of Bu^tLi in hexane gave the corresponding di-tert-butyl derivative Ap^9MeY(Bu^t)₂(THF) (5). Molecular structures of complexes 3 and 4 were established by X-ray diffraction. A method of the ligand solid angles was used to calculate the completion degree of the metal atom coordination sphere for the series of isomorphic derivatives (Ap*)Ln(CH₂SiMe₃)₂(THF) containing the central metal ions with different ionic radii (Sc, Y, Yb, Lu). According to this method, the amidopyridinate ligand solid angle in these complexes virtually does not vary, while the solid angles of coordinated THF molecule and alkyl ligands vary within a wide range.

A new efficient method for the fabrication of corrosion-resistant composite superhydrophobic coatings on aluminum and its alloys is presented. The laser micro- and nanotexturing of the surface combined with the deposition of a hydrophobic agent makes it possible to obtain superhydrophobic coatings with unique properties on aluminum materials. The complex studies by electrochemical methods and wettability analysis showed that the proposed type of coatings is characterized by very high resistance to corrosion, including pitting resistance, and by the durability of the superhydrophobic state upon prolonged contact with aqueous chloride-containing media.

Palladium supported on carbon (Pd/C) catalysts (0.55–0.65 wt.% of Pd) were synthesized by pyrolysis of birch sawdust under inert atmosphere proceeded by prolonged impregnation of sawdust in aqueous solution of palladium nitrate. In some cases, hydrothermal treatment (HT) of the pristine sawdust was conducted to modify the specific surface area of the final carbon material applied as a catalyst support. Based on low-temperature nitrogen adsorption technique, it was postulated that HT of sawdust in the liquid phase increases. while HT in the gaseous phase decreases the specific surface area of Pd/C. The obtained catalysts contained Pd particles (size ranged from 2 to 10 nm) both coated and not coated with carbon shell as evidenced by XPS and TEM techniques. The synthesized Pd/C composites provide high conversion of chlorobenzene and high selectivity in respect to benzene in hydrodechlorination reaction performed in a flow fixed-bed reactor in the presence of H₂. XPS data for Pd/C composites tested in the catalytic reaction indicate their high resistance to HCl. A minor part of metal Pd was found to transform into PdCl₂ and PdO.

Features of allylation of norbornadiene (NBD) with allyl formate were investigated in the presence of Pd catalysts. In addition to the products of single or double allylation and hydroallylation of NBD, the products of secondary transformations, hydration and hydroformylation, have been found. An effect of triphenylphosphine on the reaction direction was studied.

Potential NO donors, 1,1’-[methylenebis(oxy)]bis[3-(2-hydroxyethyl)triaz-1-ene 2-oxides], were derived from 3-alkyl-3-(2-acetoxyethyl)-1-chloromethoxytriaz-1-ene 2-oxides and 3-alkyl-1-hydroxy-3-(2-hydroxyethyl)triaz-1-ene 2-oxide sodium salts.

The efficient method for the synthesis of novel trifluoromethyl-containing hydroxy- and aminostyrenes has been developed. The reaction sequence includes the selective insertion of CF₃-substituted carbene, which was catalytically derived from methyl 3,3,3-trifluoro-2-diazopropionate, into the OH- or NH-bonds of easily available o-bromophenol and o-bromoaniline derivatives followed by a bromine substitution for vinyl group via Pd-catalyzed Stille reaction.

One-pot synthesis of 3-chloro-1,2,5-thiadiazoles from monosubstituted glyoximes and sulfur monochloride was developed.

An improved method for the synthesis of two symmetric biscrown-containing and one model tetramethoxy-substituted 1,4-distyrylbenzenes was suggested. The structures of compounds were established by ¹H and ¹³C NMR spectroscopy and X-ray diffraction analysis. Spectrophotometric and fluorescent titration were used to determine spectral properties, stoichiometry, and stability of complexes of biscrown-containing 1,4-distyrylbenzenes with alkali and alkaline-earth metal cations. The stability of the complexes was found to depend on the metal cation size and charge, as well as on the size of the crown ether fragment. The electrochemical oxidation and reduction potentials of the biscrown-containing 1,4-distyrylbenzenes and the model compound in solution were determined and their basic differences from the corresponding characteristics of biscrown-containing stilbenes were identified.

An efficient procedure for the synthesis of tris(cyclopentadienyl)zirconium tetrakis-(pentafluorophenyl)borate [Cp₃Zr][B(C₆F₅)₄] was suggested based on the reaction of Cp₄Zr with [Ph₃C][B(C₆F₅)₄]. The synthesized compound was characterized by IR and NMR spectroscopy.

Hybrid γ-carboline-based compounds containing a nitrooxy group as an NO-donor were prepared. It was shown that the introduction of this group did not affect the inhibitory activity of γ-carboline pharmacophore against acetyl- and butyrylcholinesterase.

Several fucoidan fractions were isolated from the biomass of the Kamchatka brown alga Laminaria bongardiana by hot water extraction followed by anion-exchange chromatography. Fucoidans were found to be composed of l-fucose, d-galactose, and sulfate as the major components, whereas d-xylose, d-mannose, d-glucuronic acid, and acetate were detected as the minor constituents. Highly sulfated fucoidan fractions F-2 and F-3 were solvolytically desulfated by heating in dimethyl sulfoxide in the presence of pyridine. The structures of native and desulfated polysaccharides were investigated by the methylation analysis and NMR spectroscopy. It was shown that F-2 contains fucan sulfate, the backbone of which is made of 1→3-linked α-l-fucopyranose residues with single α-l-Fucp branches at positions 2 and sulfate groups predominantly at positions 4. Sulfated fucoglucuronomannan, fucoglucuronan, and fucogalactan were detected in F-2 as concomitant polysaccharides. Fucan sulfate and sulfated fucogalactan were the major components of the fraction F-3. The anticoagulant properties of fucoidan fractions were assessed. It was demonstrated that the activity of the fraction F-3 is comparable with that of low-molecular-weight heparin (enoxaparin), whereas the activity of total fucoidan F and the fraction F-2 is ~2/3 and ~1/2, respectively, of the activity of F-3, which is in accordance with the lower sulfate content in these samples. Desulfated preparations F-2deS and F-3deS were completely devoid of anticoagulant activity.

As a part of development of medicine for extreme situations, we determined, for the first time, the protein composition of the exhaled breath condensate (EBC) of cosmonauts before and after long-lasting orbital flights on the International Space Station (ISS). The analysis was performed by electrospray ionization ion cyclotron resonance mass spectrometry. The pattern of variation of the protein composition of the exhaled air during preflight preparation, at the time of landing, and seven days after landing was elucidated. Forty-four proteins, which appeared in the exhaled breath condensate of the cosmonauts after a long orbital flight and landing and were absent before the flight, were detected. These proteins included the immune response proteins, indicating cell and blood vessel damage. In some cases, a temporary appearance of cancer markers was noted.

New potentially pharmacologically active complexes of general formula n[(HOCH₂CH₂)₃N—O]·MX₂ (M = Zn, Co, Ni, Cu; X = Cl, MeCO₂, ArOCH₂CO₂; n = 1, 2) were synthesized by the reaction of triethanolamine N-oxide with essential metal salts.

New oxovanadium(V) complexes with 2-[hydroxy(diaryl)methyl]-8-hydroxyquinoline ligands were synthesized. These compounds were found to be efficient tandem catalysts of oligomerization of hex-1-ene and alkylation of toluene, which leads to the mixture of hexyl-, dihexyl-, and trihexyltoluenes with the conversion of the starting alkene more than 99%.

5-Amino-(tert-butyl-NNO-azoxy)-1,2,3,4-tetrazine 1,3-dioxide reacts with nitronium tetra-fluoroborate to give 5-amino-6-nitro-1,2,3,4-tetrazine 1,3-dioxide. This compound is of interest as a new energetic material. A plausible reaction mechanism involves electrophilic substitution of the tert-butyl-NNO-azoxy group by the nitro group.

For the first time, the essential oil from the bark of Frangula alnus Mill. was extracted using the hydrodistillation method and examined by gas chromatography equipped with a flame ionization detector and gas chromatography coupled with mass spectrometry. Thirty-one compounds were identified, constituting approximately 94.2% of the oil of F. alnus. The essential oil of F. alnus is rich in oxygenated monoterpenes and oxygenated sesquiterpenes (28.0 and 35.8% of the essential oil, respectively). Nine oxygenated monoterpene and six oxygenated sesquiterpene compounds were identified. The essential oil of F. alnus contains epoxygeranial (6.0%) and geranial (5.5%) (as main oxygenated monoterpenes) and also caryophyllene oxide (17.7%) and spathulenol (11.3) (as main oxygenated sesquiterpenes). Since the essential oil of F. alnus is rich in caryophyllene oxide, it can be used as a preservative in food, drugs, and cosmetics. Importantly, the high content of spathulenol makes the essential oil of F. alnus a good candidate for combination chemotherapy of the multidrug resistance cancer. Spathulenol highly promotes the accumulation of rhodamine123 (substrate of the ATP-binding cassette sub-family B member 1 (ABCB1)) by the multidrug resistance cells, which over-expresses the ABCB1 efflux pump.

The results of qualitative analysis of organic acids in multivitamin mixtures No. 1 and No. 2 are presented. The contents of malic, citric, and ascorbic acids were established in the mixtures by thin layer chromatography. The quantitative analysis of the sum of organic acids and ascorbic acid was carried out using the developed potentiometric titration procedure, and the results were compared with the data of indicator titration and coulometry. The advantage of using potentiometry for a more exact establishment of the final titration point was shown.