Home – Home – Jornals – Chemistry for Sustainable Development 2009 number 1

Review deals with the discussion of the state existing in the world in the area of developments of selective narcotic analgesics of different structural types based on the synthetic transformations of tebain.

Dynamics of the anode oxidation of sulphite and thiosulphate solutions (concentration: 10 g/l) on carbon felt VNG-30 and "Karbolon V-22" under different electrolysis conditions was investigated. It was established that these materials are rather stable under anode polarization to ϕ ≈ 1.7 V (c.s.e.) and may be used for the anode oxidation of sulphite and thiosulphate ions. It was demonstrated that the oxidation rate increases with an increase in the anode polarization, especially with a decrease in the concentration of the oxidizing anions. It was shown that the addition of KBr (up to 10 g/l) to the solution causes a substantial acceleration of the oxidation of both sulphite and thiosulphate.

Dry, waste-free and energy-saving synthesis of cathode materials for lithium ion rechargeable batteries based on solid solutions of the composition LiNi_1-yCo_yO₂ (y = 0.2, 0.4, 0.6, 0.8) was carried out. Double hydroxides of nickel and cobalt, as well as anhydrous oxides of nickel and cobalt in mixture with lithium hydroxide were used as the initial reagents. It was shown that, independently of the initial reagents, the samples are characterized by high dispersity, phase uniformity and are indexed in the space group R3m. With an increase in nickel content, lattice parameters а and с increase; a good correspondence with Wegard rule for solid solutions in the system LiNiO₂-LiCoO₂ is observed. The bands in the IR spectrum shift to smaller frequencies as a result of a decrease in covalence in the layer (Ni_1-yCo_yO₂)₂. The ^6,7Li NMR spectra contain two components which are shifted both to the positive and to the negative region and provide evidence of the interaction of lithium ions with Ni³⁺ ions in the first and the second coordination spheres. Analysis of the fine structure of the second component of MAS spectra situated near 0 ppm showed that nickel ions in the layers Ni_1-yCo_yO₂ are distributed non-uniformly for 0.6 ≤ (1-y) ≤ 0.8. Such a deviation from the random distribution of Ni/Co has a narrow local character and is not detected by means of XPA but affects the electrochemical properties of cathode materials.

In order to improve the efficiency of the production of lithium compounds from crude spodumene ores, the possibility of their integrated processing using the lime high-temperature treatment of spodumene is demonstrated.

Interaction of β-pinene epoxide with some amines (butylamine, diethylamine, piperidine, morpholine) under the action of the microwave radiation is investigated. It is established that opening of the epoxide cycle occurs in all the cases, and mainly a pair of isomeric amino alcohols (2-{amino-methyl}-6,6-dimethyl-bicyclo[3.1.1]heptane-2-ols) is formed. In all the experiments involving column chromatography, one of the isomers was isolated and characterized; for piperidine, both isomers were. characterized. In the experiment with butylamine, 1-para-menthene-7,8-diol was isolated from the reaction mass; in the case of diethylamine, an amino alcohol of menthane structure was isolated.

In the course of ecological and chemical investigations of mercury content in the environmental objects, comparative evaluation of the accumulating abilities of various natural indicators was carried out for the bog and urban ecosystems as examples. Experimental data on mercury content in urban soil, peat, lichens, moss, wood and needles of conifers are presented.

Changes in the composition of the organic component of bitumen-saturated sandstone arising as a result of its mechanical treatment in AGO-2 set-up in the medium of argon and hydrogen were investigated. It was shown that the mechanical treatment in the medium of argon causes a decrease in the yield of bitumoid (organic component), a decrease in the concentrations of pyrobitumen, oil, saturated hydrocarbons and triarenes, while the fraction of tar increases sharply. Treatment of sandstone in the medium of hydrogen does not cause any substantial changes of the material constitution of bitumoid in comparison with the initial sample; however, the content of saturated, bi- and triaromatic hydrocarbons in the hydrocarbon group composition of this bitumoid is much lower than that in the bitumoid of the initial sandstone.

Different methods of the mechanochemical intensification of the process of collagen dissolution are proposed: cavitation at the stage of preliminary treatment of the collagen-containing material and mechanical mixing at the stage of dissolution in acetic acid. In order to obtain pure products of collagen dissolution which would not be contaminated with chemical reagents and would be suitable for use as raw materials in medicine and in food industry, treatment with a set of enzymatic agents is used. Colloid solutions conserving the fibrous structure necessary for further use of the products of collagen dissolution were obtained.

Methyl ester of cannabigerorcynic acid 1, previously unknown derivative of octahydroxanthenol 2 and daurichromenic acid 4 were isolated from the lipophilic extracts of Rh. adamsii. Derivatives of compounds 1 and 2 were obtained. It was shown that xanthenol 2 possesses coagulating and hypothermic effect. Methyl ester of cannabigerorcynic acid was discovered in a natural object for the first time.

Optimal descriptors were determined on the basis of the data obtained by means of SMILES (simplified molecular input line entry system). It was established that they give a satisfactory prediction of the logarithms of maximum permissible concentrations of the substances that may be present in the air of the working area during the production and processing of plastics.

Results of photoactivated galvanochemical oxidation of 2,4-dichlorophenol in aqueous solution in a flow reactor of the film type are discussed. It is established that photoactivation promotes an increase in the rate constant of the oxidation of 2,4-dichlorophenol by a factor of 1.7 due to the acceleration of destruction of intermediate products and allows one to achieve almost complete mineralization of the substrate.

Effect of water and salt content of oil emulsions on the group composition of their interfacial layer was investigated. It was shown that an increase in water and salt content causes an increase in the fraction of heteroatomic components, an increase in the degrees of cyclicity and aromaticity of pyrobitumen species extracted from the interfacial layers of emulsions, in comparison with pyrobitumen of oil.

The state of the problem of production of the synthetic hydrocarbon fuel abroad and in Russia is considered. It is shown that abroad, in view of the limited oil resources, new energy strategies were adopted and are put into effect. These strategies are aimed at diversification of energy carriers, involvement of nonconventional kinds of organic raw materials (mainly coal and natural gas), as well as plant raw materials, into industrial processing to obtain ecologically safe liquid fuel, and establishment of the corresponding production. It was stressed that the technologies of the production of synthetic liquid fuel from coal reached the level of commercial efficiency. In Russia, it is necessary to develop and accept, as soon as possible, a novel energy strategy aimed at the creation of competitive technologies for advances oil processing and for obtaining high-quality and ecologically safe liquid hydrocarbons from coal and natural gas.

Microelement composition of the collection of salivolith samples taken from patients living in Novosibirsk, Vladivostok and Omsk was examined. Analysis of the microelement composition of the samples showed that the elements under determination are distributed extremely non-uniformly over the groups of salivoliths from patients living in different regions. Thus, salivoliths from the Vladivostok collection are characterized by higher content of selenium, iodine, vanadium, chromium and manganese but indium and cadmium occur in them more rarely than in the samples from Novosibirsk and Omsk. The salivoliths from the Omsk collection contain larger amounts of titanium, copper and zirconium than the samples from Novosibirsk and Vladivostok do, while some samples contain almost zero amounts of selenium and iodine, which is due to the specific features of the region.

An efficient dechlorination method for p-nitrochlorobenzene, p-chloroanisole and 1-chloronaphthalene on municipal waste incinerator fly ash in presence of reducing agents with water/alcohol mixtures was developed. Dechlorination reactions showed higher activity in water/isopropanol mixture at temperature <100 ^oC. Metal contents of fly ash (copper and lead) played a vital role to enhance dechlorination at low temperature <100 ^oC. Moreover, the fly ash also provided the surface to accomplish reduction and substitution reactions by adsorbing the chlorinated aromatic compounds, hydrogen and hydroxyl ions. The mechanism of dechlorination was envisaged.

Concentrations of different classes of lipids and fatty acids in muscles and liver of black Baikalian grayling Thymallus arcticus baicalensis Dybowski, 1874 were determined for the first time. Neutral lipids (triglycerides) were detected to prevail in all the investigated tissues, while phospholipid content of red muscles is two times lower than that of white muscles. The composition of fatty acids of total lipids for all the organs is dominated by polyunsaturated (44.58-53.7 %) and saturated (19.06-30.94 %) acids. Polyunsaturated ones are mainly represented by the 22:6n-3 and 20:5n-3 acids; their total fraction was 19.5-39.1 %. The ratio of fatty acids of the n-3/n-6 series depends on tissue kind and varies within the range 2.19-4.02. In the lipids of white muscles, the fraction of polyunsaturated fatty acids is higher due to docosahexaenoic acid. For the reason of total fattiness and the balanced ratio of polyunsaturated fatty acids of the n-3/n-6 series in the muscle tissues, black Baikalian grayling may be used as a high-quality raw material for developing dietary and specialized food products and biologically active additives.

Within DFT(B3LYP) methods, the potential interaction surface of a monomethyl mercury cation with G, H, S, and Y amino acids entering into the composition of the active cavity of acetylcholinesterase is studied. The preference for different centeres of amino acids for the interaction with the metal atom is investigated. The principal possibility of C_α-deprotonation of amino acid as a result of the interaction with the electronegative carbon center of methylmercury is analyzed. The effect of deprotonation is shown to cause demethylation of methylmercury. Iterative action is assumed to occur in Hg(II) and MeHg⁺ biochemical objects, which explains the high toxicity of microconcentrations of these compounds.

The problem of a comparison of quantum chemical calculation results with the experimental characteristics of molecules is discussed, and it is noted that the accuracy of quantum computations can be most fully evaluated by a comparison of the theoretical results with the experimental spectra. By means of calculations, the contribution of anharmonism to the theoretical values of absorption band intensities in the IR spectra of 15 fluoro and 36 chloro derivatives of hydrocarbons is estimated. The first and second derivatives of the molecular dipole moment are obtained by ab initio quantum chemical calculations with the use of the 6-31G(1d) basis set and allowance for electron correlations by the second order Möller-Plesset method. The performed calculation well reproduces the positions of maxima and the intensity ratio of fundamental, overtone, and complex absorption bands.

The results of IR and single crystal X-ray diffraction studies on the dynamics of molecular groups and structural changes in L-alanine and DL-alanine -CH(CH₃)-COO^-) with temperature variation are given. An analysis of changes in the 4000-600 cm^-1 frequency range of the IR spectra with temperature variation reveals the occurrence of the anomaly for the ~974 cm^-1 band in DL-alanine, which is similar to the anomaly for the 955 cm^-1 band, previously described for L-alanine. The X-ray diffraction data for L- and DL-alanine show that no dramatic changes in the unit cell parameters, conformations of amino acid molecules themselves, and hydrogen bond lengths occur with temperature variation, which would indicate the structural phase transition. Changes in the IR spectra of L-alanine and DL-alanine with temperature variation are compared to the changes in the vibrational spectra of other amino acids on cooling.

Calculations at the density functional theory level show that for phenanthrene, unlike anthracene, stable dimeric structures are absent. A study of the absorption and photoluminescence spectra of crystalline phenanthrene under a pressure to 30 kbar and a simultaneous shear reveals reversible changes in the spectra: a shift of absorption bands and luminescence to the long wave region, a decrease in the intensity, and disappearance of the vibrational structure. Unlike anthracene, the dimerization (and other irreversible transformations) of phenanthrene under the simultaneous effect of high pressure and shear is not observed.

Changes in the atomic and electronic structures of free NaCl clusters as the cluster size function are analyzed based on density functional theory and the finite difference method. It is shown that the geometric atomic structure of clusters distorts more with decreasing size. Along with this, an increase in the HOMO-LUMO gap is observed.

A copper bromide complex based on benzoin 1′-phthalazinylhydrazone is synthesized. Within density functional theory (OPBE/TZP) the optimal structural parameters of the complex are determined. X-ray Absorption Near-Edge Structure (XANES) spectra above the K absorption edge of copper are measured in the copper bromide complex. Theoretical XANES spectra of the K absorption edge of copper are calculated based on the full multiple scattering method and in the full potential of the finite difference method. Good agreement between the theoretical XANES spectrum and the experimental data is obtained.

The procedure of approximate summation is applied to a series of many-body perturbation theory for the internal energy of a dipolar hard sphere (DHS) fluid to produce an expression similar to the mean field approximation in the Widom-Rowlinson penetrable sphere model, which is well consistent with the experiment at moderate or high densities. Similar results are obtained from the hindered rotation model generalized for arbitrary density. The critical parameters ρ_с, P_c and T_c of both models are consistent with the data of machine experiments and are close to the parameters of the percolation transition in the DHS system.

The models of hexane, 2,3-dimethylbutane, and cyclohexane are obtained by the method of classical molecular dynamics using the GROMACS software package. Two different force fields (the all-atom description and the approach of united atoms) are used. Radial distribution functions (RDFs) are calculated for the molecular centers of mass, and the shapes of Delaunay simplices are analyzed. It is shown that the most compact molecules (cyclohexane and 2,3-dimethylbutane) are located in the space as atoms in simple liquids. Thus, the structural distinctions between liquid cyclohexane and 2,3-dimethylbutane are the same as between simple liquids of the corresponding density.

Structural characteristics of the hydration complexes of non-electrolytes such as the hydration numbers h, molar adiabatic compressibility of hydration complexes β_hV_h, the molar volume of water in the hydration sphere V_1h, the solute molar volume without hydration environments V_2h and others are determined using the data on the ultrasonic velocity, the density and heat capacity of aqueous solutions of urea, urotropine, acetonitrile, and a number of amides of N-acetyl amino acids. A theoretical model of solvation is also applied. A comparison of the environments of hydrated urotropine molecules with those of urea and acetonitrile molecules in an aqueous medium shows a considerable hydrophobic interaction of urotropine with a solvent.

¹³C NMR chemical shifts are obtained for aqueous solutions of alkylammonium chlorides (С₆-С₉) in the region of the critical micelle concentration (CMC). A new method of processing ¹³C NMR experimental data for aqueous solutions of alkylammonium chlorides is developed to calculate the aggregation numbers N of micelles and the equilibrium constants K of the micelle formation within the law of mass action. With the use of these N and K values the standard Gibbs energy of the micelle formation and its increment of
-1.8 kJ/mol are found for the methylene group. A small increment confirms the hypothesis about the structure of micelles consisting of both contact and hydrated associates. The structural model of the association of alkylammonium chlorides in water, the effect of alkyl chain length on the CMC, the hydrophobic interaction, the formation of hydrate associates, and also a possible classification of surfactants based on this are discussed.

On the example of noncentrosymmetric (NCS) crystals of phosphates, the composition-structure-property relationship is systematized, and a set of phosphate structures is plotted on the plane of oxide bond lengths. This set is shown to be located in 12 subregions of the rosette formed of three ellipses of acentricity containing the crystals with different structures and nonlinear optical properties. One-to-one correspondence between the structure and the set of NCS properties of crystals makes it possible to more reliably determine their structural physical data.

Coatings containing high-temperature phases of tungsten borides W₂B and β-WB are obtained on titanium and steel targets by a shaped charge explosion. In some regions of the target, microhardness achieves ≥42 GPa. The phase composition of different regions of the coatings is examined by X-ray diffraction. The values of unit cell parameters indicate the formation of phases with variable composition. The crystal structure of β-WB is refined.

The [Zn(phen)₃](2,2′-Bipy-5,5′-dicarboxylate)·12H₂O complex is synthesized and its crystal structure is determined by single crystal X-ray crystallography. The crystals of the coordination compound have a monoclinic unit cell with parameters a = 12.2533(14) Å, b = 18.976(2) Å, c = 22.426(3) Å, β =105.675(2)°, V = 5020.54(300) ų, Z = 4, P2₁/n space group. The environment of the Zn atom is a distorted octahedron of six N atoms belonging to three coordinated phen molecules. In the structure, π-π interactions between phen molecules as well as between phen molecules and 2,2′-bipyridyl-5,5′-dicarboxylate anions give rise to the formation of three-dimensional ensembles. The 2,2′-bipyridyl-5,5′-dicarboxylate anion and twelve water molecules are not coordinated, and the molecules of water of crystallization make clusters.

Single crystal XRD is used to study the crystal structure of a new compound containing the dicarbollyl cluster anion Co(III) with the composition [CuPhen₃][Co(C₂B₉H₁₁)₂]₂·CH₃CN, where Phen is 1,10-phenanthroline. The crystallographic dat a: C₄₆H₇₁B₃₆N₇Co₂Cu, M = 1292.66, monoclinic system, P2₁/с space group, unit cell parameters a = 14.7178(2) Е, b = 19.5640(4) Е, c = 22.8663(5) Е, І =106.6601(7)°, V = 6307.75(33) Е³, Z = 4, d_x = 1.361 g/cm³, T = 100 K, ј = 0.90 mm^-1. The structure is solved by the direct method and refined by the full-matrix LSM in an anisotropic-isotropic (for H atoms) approximation up to the final agreement factors R₁ = 0.0370, wR₂ = 0.0869 for 13,807 I_hkl e 2Г_I out of 18,295 measured I_hkl. The structure consists of [CuPhen₃] cations, Co(C₂B₉H₁₁)₂ anions, and acetonitrile molecules MeCN. The central Cu atom in the cation in the general position, and its coordination geometry is a distorted extended octahedron formed by six nitrogen atoms of the three bidentate Phen ligands. The coordination of Cu(II) in the cation is (2+2+2) with two long axial and four shorter equatorial Cu-N bonds, whose average lengths are 2.239(2) Е and 2.077(1) ъ respectively. Each anion has its own position of the-C₂- groups; for Co(1), it is a quasi-gauche-configuration; for Co(2), a quasi-trans-configuration.

The two title compounds were prepared from the ligand pydc with cobalt(II) acetate in the presence of L¹ and L² (L¹ = 1,3-bis(4-pyridyl)propane, L² = 3-amino-1H-1,2,4-triazole, pydc = 2,6-pyridinedicarboxylic acid). The complexes were characterized by elemental analysis, IR spectrum and single crystal X-ray diffraction. Single crystal analysis shows that in two complexes coordination number around Co atom is six with distorted octahedral geometry, and both two complexes consist of ion pairs containing cationic [Co(H₂O)_n]²⁺ and anionic [Co(pydc)₂]^2- units.

The paper describes the synthesis of geometrical isomers and diastereomers of Pt(II) bischelates with diastereomeric hydroxy-amino acids threonine (threo-α-amino-β-hydroxybutyric acid CH₃C*H(OH)C*H(NH₂)COOH=ThrH) and allothreonine (erythro-α-amino-β-hydroxybutyric acid=alloThrH) containing two asymmetric carbon atoms C*: cis-,trans-[Pt(S-Thr)₂], cis-,trans-[Pt(R-Thr)(S-Thr)], cis-,trans-[Pt(R-alloThr)(S-alloThr)] (where R and S are the absolute configurations of the asymmetric carbon atom bonded to the carboxyl group). ¹⁹⁵Pt NMR spectroscopy is used to investigate the successive phases of the synthesis of the stereoisomeric Pt(II) complexes with threonine. The synthesized complexes are studied by ¹H, ¹³C, ¹⁹⁵Pt NMR spectroscopy, IR spectroscopy, and single crystal XRD.

By single crystal X-ray analysis, the atomic structure of the crystals of [Eu(NО₃)₃(HMPA)₃] complex (HMPA is hexamethylphosphorotriamide) possessing intense triboluminescence is determined. Symmetry of centrosymmetrical crystals is monoclinic: a = 13.785(1) Å, b = 19.746(2) Å, c = 14.723(1) Å, β =102.143(2)°, P2₁/n space group, Z = 4, d_x = 1.484 g/cm³. The crystal structure is represented by separate С₁₈Н₅₄EuN₁₂O₁₂P₃ complexes linked by van der Waals interactions with pronounced cleavage planes. The coordination polyhedron of Eu(III) atom reflects the state of distorted square antiprism. The possible causes of spectral differences in the Stark structure of photo- and triboluminescence are discussed.

Dense thin nanostructured films of cadmium sulfide CdS obtained by chemical deposition from aqueous solutions are strongly bound to a substrate due to the formation of cadmium hydroxide Cd(OH)₂ in the system. By X-ray reflectometry and grazing incidence diffraction it is found that at the beginning of the deposition a dense Cd(OH)₂/SiO₂ layer is produced on the surface of a silicon or glass substrate. This layer is formed through the atomic-layer adsorption of crystalline 1-3 nm thick Cd(OH)₂ film by the oxygen-containing substrate surface. During sulfidation of this cadmium-containing substrate layer, a surface nucleation layer of CdS/Cd(OH)₂/SiO₂ forms, which provides the growth, denseness, and strong adhesion to the substrate of nanostructured CdS film with a disordered structure. According to the obtained experimental data, a "hydroxide scheme" of film deposition is confirmed and refined, and the stages of CdS nanofilm formation are determined.

The review generalizes the structural studies on the products of the interaction of antithyroid preparations (heteroaromatic thioamides) with iodine. The n-σ* adducts of imidazol, thiazol, oxazole, pyridine, uracil derivatives with molecular iodine, iodinium salts, and also disulfides formed as a result of thione oxidation in iodine-coordinating solvents are considered. Based on mainly single crystal X-ray diffraction and Raman spectroscopy data, the structural parameters of iodine molecular complexes are shown to be highly sensitive to changes in the type of a heteroatom and substituents in the heteroring. The effect of the structure of heteroaromatic thioamides on their antithyroid activity is analyzed.

The electronic structure of MgSiN₂ and MgGeN₂ orthorhombic crystals and their sublattices was analyzed at the density functional theory level using the sublattice method. The energy-band structure of the orthorhombic crystals is compared to the structure of their hypothetic analogues with the chalcopyrite lattice. The origin of the specific features of the valence band structure from the sublattice states is determined in the studied crystals, which is mainly due to the interaction of atoms in SiN₄ and GeN₄ cation tetrahedra.

A new two-dimensional layered cadmium coordination polymer [Cd(D,L-mal)H₂O]_n (H₂mal =
= malic acid) is solvothermally synthesized and characterized by elemental analysis, IR, TG and single crystal X-ray diffraction. Each Cd(II) centre is surrounded by seven oxygen atoms from three different malate ligands and one coordinated water molecular forming a pentagonal bipyramidal configuration. Furthermore, complex 1 exhibits blue intense photoluminescence property at room temperature.

Two new cadmium(II) complexes, Cd₂(L1)₂(NCS)₂ (1) and Cd₂(L2)₂(NCS)₂ (2), where L1 and L2 are the deprotonated forms of 2-[(3-dimethylaminopropylimino)methyl]-6-ethoxyphenol and 2-methoxy-6-[(pyridin-2-ylmethylimino)methyl]phenol, respectively, have been isolated as crystalline products and characterized by elemental analysis, IR spectroscopy, and single crystal X-ray diffraction method. Both compounds are structurally similar and are phenolate-O-bridged dinuclear cadmium(II) complexes. Each Cd(II) cation in the complexes is octahedrally coordinated. The Cd…Cd distances in (1) and (2) are 3.618(2) and 3.571(2) Å, respectively.

Polycrystals of [Pt(NH₃)₅Cl](PO₄)·2H₂O complex salt are analyzed using single crystal XRD (STADI-P autodiffractometer, CuKα₁-radiation, position sensitive detector). Crystallographic characteristics are as follows: a = 9.2447(2) Å, b = 7.3122(1) Å, c = 9.2005(1) Å, β = 109.938(1)°, Р2₁/m space group, V =584.67(2) ų.

Methyl 20-isopropyl-15(E)-hydroxyimino-5,9-dimethyl-18-oxahexacyclo [12.4.0.2^2,13.1^18,20.0^5,10.0^4,13]-heneicosane-9-carboxylate is synthesized and its molecular structure is determined. Compound IIа of С₂₇H₄₁NO₄ crystallizes in the acentric P2₁ space group with the following unit cell parameters: а = 7.6511(7) Å, b = 12.0698(11) Å, c = 12.9182(12) Å, β = 95.257(2)°.