Vol 65, No 5 (2016)

Rheological properties of associates formed by interaction of trimethyl[methacryl-oxyethyl]ammonium methyl sulfate with sodium octyl- and dodecyl sulfate micelles, as well as associates of sodium 4-styrenesulfonate with dodecyltrimethylammonium bromide micelles in aqueous solutions were studied by steady shear and oscillatory (dynamic) shear measurements with Fourier transform. It was shown that viscosity depends on the composition and achieves maximum value at equimolar ratio of components for two of studied systems. The extremal dependence of the viscosity vs. composition is not observed for systems with sodium octyl sulfate due to weak interactions between the components. The systems exhibiting the anomalous dependencies of concentration to viscosity are viscoelastic fluids due to the physical entanglements between the associates.

A reaction of digallane [(dpp-bian)Ga—Ga(dpp-bian)] (1) (dpp-bian is the 1,2-bis[(2,6-disopropylphenyl)imino]acenaphthene) with one equivalent of I₂ leads to oxidation of (dpp-bian)^2– in compound 1 to (dpp-bian)–and gives [(dpp-bian)GaI—GaI(dpp-bian)] (2). In the reaction of compound 2 with two equivalents of (acac)Na, not only exchange of the iodide and acetylacetonate ions takes place, but also a transfer of electrons from the metal—metal bond to dpp-bian with the formation of the complex [(dpp-bian)Ga(acac)] (3), in which the dpp-bian ligand is a dianion. A reaction of digallane 1 with 2,2´-bipyridyl at 200 °C in toluene in a sealed tube leads to the reduction of 2,2´-bipyridyl and gives the complex [(dpp-bian)Ga(bipy)] (4), which contains two different chelate redox-active ligands. The new compounds were characterized by IR (3, 4), NMR (3), and ESR spectra (4), the structures of both derivatives were established by X-ray diffraction.

A reaction of benzophenone with bis(3,5-di-tert-butylpyrazolyl)methyllithium (3,5-Bu^t₂C₃HN₂)₂CHLi (obtained in situ by metallation of (3,5-Bu^t₂C₃HN₂)₂CH₂ with n-butyllithium in THF at–70 °C) led to the synthesis of alkoxide lithium complex [(3,5-Bu^t₂-C₃HN₂)₂CHCPh₂O]Li(THF) (1) containing a new monoanionic heteroscorpionate ligand [(3,5-Bu^t₂C₃HN₂)₂CHCPh₂O]^–. Hydrolysis of complex 1 gave 2,2-bis(3,5-di-tert-butylpyrazolyl)-1,1-diphenylethanol (2) in 90% yield. The structure of alcohol 2 was established by X-ray crystallography. A reaction of anhydrous YCl₃ with two molar equivalents of lithium alkoxide 1 in THF furnished yttrium monochloride complex [(3,5-Bu^t₂C₃HN₂)₂CHCPh₂(μ-O)]₂-YCl(THF)[(μ-Cl)Li]₂ (3). According to X-ray diffraction data, chloride 3 is a monomeric ate-complex with one terminal and two bridging chloride ligands. The nitrogen atoms of the pyrazole rings are not involved in the coordination of the ligand with the yttrium ion. The bisalkyl complex [(3,5-Bu^t₂C₃HN₂)₂CHCPh₂O]Y(CH₂SiMe₃)₂(THF)₂ (4) obtained by the reaction of alcohol 2 with an equimolar amount of Y(CH₂SiMe₃)₃(THF)₂ turned out to be unstable and completely decomposed in solution in C₆D₆ at 25 °C within two hours. An exchange reaction of equimolar amounts of YCl₃ and {[o-Me₂NC₆H₄CH₂C(NCy)₂]Li(THF)₂}₂ (5) (Cy is the cyclohexyl) in THF led to the formation of a neutral monochloride complex [o-Me₂NC₆H₄CH₂C(NCy)₂]₂YCl(THF)₂ (6). A reaction of complex 6 with an equimolar amount of o-Me₂NC₆H₄CH₂Li in toluene led to the synthesis of a new yttrium aminobenzyl complex [o-Me₂NC₆H₄CH₂C(NCy)₂]₂Y[CH₂C₆H₄-o-NMe₂] (7). X-ray diffraction studies showed that in complexes 6 and 7 the donor NMe₂ groups of amidinate ligands are not involved in the metal—ligand interaction. Yttrium complexes 4 and 7 exhibited catalytic activity in polymerization of isoprene.

The dispersing action of the surfactant (sodium dodecyl sulfate, SDS) on the carbon nanotubes (CNT) in aqueous medium has been studied. Electron microscopy, molecular docking, NMR and IR spectroscopies were applied to determine the physical-chemical properties of CNT dispersions in SDS—water solutions. It was established that micellar adsorption of the surfactant on the surface of carbon material and solubilization of SDS in aqueous medium contribute to improving CNT dispersing in water solutions. It was shown that the non-polar hydrocarbon radicals of a single surfactant molecule form the highest possible number of contacts with the graphene surface. Upon increase of the SDS in solution these radicals form micelles connected with the surface of the nanotubes. At the sufficiently high SDS concentration the nanotube surface becomes covered with an adsorbed layer of surfactant micelles. Water molecules and sodium cations are concentrated in spaces between micelles. The observed pattern of micellar adsorption is somewhat similar to a loose bilayer of surfactant molecules.

The reaction of 2-aryl-1,1-dibromocyclopropanes with adduct NOCl·(SO₃)_n leading to 3-aryl-5-bromoisoxazoles as a result of nitrosation—heterocyclization of the cyclopropane ring was studied. The reaction is accompanied with electrophilic aromatic bromination. The mechanism of the transformation was discussed, the optimal reaction conditions to enhance the reaction selectivity were developed.

An acid-catalyzed reaction of (–)-caryophyllene oxide with tert-butanethiol led to sulfides with the clovane structure of the sesquiterpene fragment in up to 63% yields. The oxidation of these sulfides gave sulfoxides in up to 38% yields (de 59%) and sulfones in up to 89%.

Solubilization capacity of a number of nonionic micelle-forming compounds toward 2,2´-bibenzimidazole and its alkylated derivatives was determined by spectrophotometry. It was found that as the hydrophilic lipophilic balance of the studied amphiphiles grows, their solubilization effect toward 2,2´-bibenzimidazoles increases and reaches the highest value in the case of pluronic F127. The conversion of bibenzimidazoles to the cationic form induced by lowering the medium pH improves efficiency of the solubilizers.

A Darzens condensation of α-chloroacetamide with aromatic aldehydes furnished a series of 3-aryl-2,3-epoxypropionamides, which were further converted to 5-[bromo(aryl)methyl]-2,2-dimethyl-1,3-oxazolidin-2-ones.

The aggregation of octa-2-hydroxyethylated calix[₄]resorcines (CR) with different alkyl chain length (R = Et, n-C₅H₁₁, n-C₁₁H₂₃), hydrophobically modified polyethyleneimine (HPEI) and their mixed systems was investigated by the tensiometry and dynamic light scattering in water and water-organic solvents at different temperatures. The critical aggregation concentration (CAC) and the size of aggregates were determined. It was established that the temperature affects significantly the surface and aggregation properties of the CR. The hydrolysis of 4-nitrophenyl-О-butylchloromethyl phosphonate was investigated in the presence of CR, HPEI, and their mixed systems by spectrophotometry. The parameters of the reaction (rate constant in the micellar phase, binding constant of the substrate with aggregates, and CAC) testify that the catalytic activity of the HPEI system in the presence of СR with undecyl radicals is the highest.

A synthesis of 1-aminophosphonate derivative of methylsiloxane oligomer was developed. A methodology of the introduction of 1-aminophosphonate fragment not only into the stable siloxane structures, but also into hydrolytically unstable alkoxyfunctional organosilicon compounds was suggested.

A possibility of electrochemical phosphorylation of coumarins (coumarin, 6-methylcoumarin, 7-methylcoumarin) with diethyl phosphite was shown. The approach is based on the oxidation of a mixture of the aromatic compound and diethyl phosphite (1: 1) under mild conditions (room temperature, atmospheric pressure) in the presence of a bimetallic catalytic systems: Mn^IIbipy/Ni^IIbipy and Mn^IIbipy/Co^IIbipy (bipy is the 2,2´-bipyridine). This method allows one to obtain diethyl arylphosphonates in high yields (up to 70%) and 100% conversion of the phosphite.

New stable tricarboxylate phosphabetaines were synthesized based on 3-(diphenylphosphino)propionic acid and unsaturated dicarboxylic acids (maleic and itaconic). A new dicarboxylate phosphabetaine was synthesized based on 1,3-bis(diphenylphosphino)propane, which did not contain any proton-donor reagents in its crystal lattice.

A condensation of phenyl- or l-menthylphosphine with formaldehyde and 4,4´-bis-(4´-aminophenoxy)biphenyl proceeding as a covalent self-assembly gave rise to the first representatives of 46-membered P,N,O-containing cyclophanes, namely, 1³,1⁷,8³,8⁷-tetra-R-3,6,10,13-tetraoxa-1,8(1,5)-di(1,5-diaza-3,7-diphosphacyclooctana)-2,4,5,7,9,11,12,14(1,4)-octabenzenacyclotetradecaphanes (R = Ph (1), l-Ment (2)). The cage macrocyclic tetraphosphine 2 reacted with (cyclooctadiene)dichloroplatinum(ii) and -palladium(ii), as well as with (tetrahydrofuran)pentacarbonyltungsten(0) with the formation of binuclear complexes, in which the metal atoms are coordinated to 1,5-diaza-3,7-diphosphacyclooctane fragments by the P,P-chelate mode.

X-ray crystallography was used to study molecular and crystal structure of 19-nor-4α-(6-hydrazonocarbonyl-3,4,5-trihydroxytetrahydropyran-2-oxycarbonyl)-16-hydrazono-ent-beyeran (1). The bulky hydrophilic substituents are on one side of the hydrophobic beyeran fragment, that leads to the layer-type crystal packing: the hydrophilic layers, in which molecules 1 and hydrate water molecules bound by the classic hydrogen bonds of the O—H...O—and N—H...O type alternate with hydrophobic layers formed by the ent-beyeran fragments.

A number of N-(4-tert-butylbenzyl)-N-(pyridin-3-ylmethyl)-2-aminothiazolines with different substituents at position 5 of thiazoline ring was synthesized and their inhibitory activity against human erythrocyte acetylcholinesterase (AChE, EC 3.1.1.7), horse serum butyrylcholinesterase (BChE, EC 3.1.1.8), and porcine liver carboxylesterase (CaE, EC 3.1.1.1) was studied, as well as their antioxidant properties in DPPH and ABTS tests (DPPH is the 2,2-diphenyl-1-picrylhydrazyl, ABTS is the 2,2´-azinobis(3-ethylbenzthiazolino-6-sulfonic acid)). All the studied compounds virtually do not inhibit AChE, whereas the inhibition degree of BChE and CaE depends on the substituent structure. The presence of radical-binding activity comparable with the standard antioxidant ascorbic acid was shown for compounds containing a iodomethyl substituent. The found lead compound (R¹ = H, R² = CH₂I) combines the antioxidant properties and the ability to efficiently inhibit BChE, simultaneously possessing an optimal esterase profile. The performed studies showed that N-(4-tert-butylbenzyl)-N-(pyridin-3-ylmethyl)-2-aminothiazolines are a new promising class of compounds, which can be used for the development of multifunctional agents for treatment of neurodegenerative diseases.

A synthetic approach to the design of new multitarget neuroprotectors consisting in combination of the tetrahydrocarbazole and aminoadamantane pharmacophore fragments through a 2-hydroxypropylene spacer upon the reaction of 9-oxiranylmethyl-2,3,4,9-tetrahydro-1H-carbazoles and aminoadamantanes, which affords 1-(adamantan-1-ylamino)-3-(1,2,3,4-tetrahydrocarbazol-9-yl)-propan-2-ols, is proposed. The effect of the synthesized compounds on the neuronal NMDA receptors and the functional characteristics of rat liver mitochondria was studied.

The aggregation and adsorption properties of a new complex of 1-hexadecyl-4-aza-1-azoniabicyclo[2.2.2]octane bromide with copper dibromide were studied by methods of conductometry, tensiometry, and dynamic light scattering. The critical micelle concentration, size of the aggregates, and adsorption characteristics at the water—air interface were determined. The antimicrobial and antifungal effects were established. The studied properties of the complex were compared with the properties of the ligand and cationic surfactants with a head group of the cyclic and acyclic types. The enhanced aggregation ability of the complex and its improved biological activity were shown.

An acid-catalyzed pyrrolidine ring opening in 2-(2-hydroxynaphthalen-1-yl)pyrrolidine-1-carboxamides in the presence of resorcinols furnished new calix[4]resorcinols or 1,1-diarylbutanes modified with urea fragments. The process follows the retro-Mannich reaction mechanism, with the 2-naphthol fragment playing the role of the leaving group.

In this article we describe the international approaches to the assessment of the level of chemical pollution of the environment on a planetary scale. Also in this article we discusse the results of assessment of chemical footprints, derived from the use of this approach for Europe as a whole and the individual European countries.