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Journal of Structural Chemistry

2010 year, number 2

1.
ELECTRONIC STRUCTURE OF CUBIC TUNGSTEN SUBNITRIDE W2N IN COMPARISON TO HEXAGONAL AND CUBIC TUNGSTEN MONONITRIDES WN

D. V. Suetin, I. R. Shein, A. L. Ivanovskii
Keywords: cubic tungsten subnitride W2N, electronic properties, FLAPW-GGA, modeling
Pages: 213-217

Abstract >>
A full potential FLAPW-GGA method is used to study for the first time the electronic structure of cubic tungsten subnitride W2N, and its equilibrium lattice parameter, density, energy of cohesion, coefficients of low temperature heat capacity and Pauli paramagnetic susceptibility are calculated. It is discussed in comparison to the similar values of hexagonal and cubic tungsten mononitrides WN.



2.
Theoretical insights into the properties of the XYв‰ЎYX…Mn+ complexes (X = H, F, Cl; Y = C, Si; M = alkaline and alkaline earth metals)

R. Ghiasi
Keywords: disilyne, disilyne complexes, interaction energy, NBO, AIM
Pages: 218-224

Abstract >>
The character of alkaline (M+= Li, Na, K) and alkaline earth metal ions (M2+= Be, Mg, Ca) interactions with disilyne and acetylene has been studied by using high-level ab initio computations. The interaction energies were calculated at MP2/6-311++G(2d,2p) level. These calculations show that the size and charge of cation are two significant factors that affect the character of interaction. AIM and NBO analyses of Mn+…X2Y2 interactions specify that the variation of densities and the extent of charge transfers upon complexation correlate well with the obtained interaction energies.



3.
A STUDY OF FACTORS AFFECTING THE ACCURAC OF COMBINED CALCULATION METHODS

R. R. Syrlybaeva, I. V. Vakulin, R. F. Talipov
Keywords: combined calculation methods, total energy calculation, nonempirical methods
Pages: 225-230

Abstract >>
By the example of combined calculation methods (CCMs) corresponding to calculations in MP4/6-311+G(fd,p)//MP2/6-31G(d,p) and MP4/aug-cc-pvTZ//МР2/cc-pvDZ approximations the factors affecting their accuracy are considered. By total energy calculations made for a number of compounds it is shown that the accuracy of CCMs reduces when valence double- and triple-split basis sets are applied together, and also when different methods are used to allow for electron correlation. The use of empirical corrections taking into account the character of the electron distribution in a molecule allows an enhancement of the accuracy of CCMs. The mentioned factors taken into account enable us to obtain CCM, for which the mean absolute deviation of calculation data is 1.0 kJ/mol and the largest maximum deviation is 8.0 kJ/mol in the total energy calculation in the MP4/6-311+G(f,d,p) approximation.



4.
PREDICTION OF The VAPORIZATION ENTHALPY Based on MODIFIED RANDIДЌ INDiCES. III. carbonic acidS

E. L. Krasnykh
Keywords: vaporization enthalpy, topological index, connectivity index, carbonic acids, energy of hydrogen bonds, QSPR methods
Pages: 231-236

Abstract >>
The vaporization enthalpies of mono- and dicarbonic acids with different structures are calculated under normal conditions using the modified Randič method and the energies of hydrogen bonds. The results demonstrate good agreement between the experimental and calculated data.



5.
Geometric and electronic structure of An N,N′-ethylene-bis(salicylaldiminato) zinc(II) molecule, ZnO2N2C16H14

G. V. Girichev, N. I. Giricheva, N. V. Tverdova, A. O. Simakov, N. P. Kuz'mina, O. V. Kotova
Keywords: structure of molecules, Schiff bases, ZnO2N2C16H14, Zn(salen), gas electron diffraction, quantum chemical calculations
Pages: 237-245

Abstract >>
Gas electron diffraction at a temperature T of 641(5) K is used to study the structure of an N,N′-ethylene-bis(salicylaldiminato) zinc(II) molecule, ZnO2N2C16H14, further Zn(salen). The structure of a gaseous Zn(salen) complex has C2 symmetry and is characterized by a substantial turn of two chelating fragments of the ligand with respect to each other, and also by a big difference in the length of coordination bonds: rh1(Zn-O)=1.902(7) Å and rh1(Zn-N)= 2.027(7) Å. Results of the DFT/B3LYP calculation with 6-31G* and CEP,TZV basis sets of the molecule structure well agree with the experimental data. The electronic structure of Ni(salen), Cu(salen), Zn(salen), and Zn(acacen) molecules is considered.



6.
structural and Thermodynamic characteristicS of ionic associates in vapors over sodium Bromide and iodide

T. P. Pogrebnaya, A. M. Pogrebnoi, L. S. Kudin
Keywords: ionic associates in vapors over sodium bromide and iodide, nonempirical calculation, geometric configuration, isomers, geometric parameters, vibrational spectra, ion-molecular reactions, formation enthalpy of ions
Pages: 246-252

Abstract >>
Nonempirical methods are used to calculate the geometric parameters, the frequencies of normal vibrations, and thermochemical characteristics of ions existing in saturated vapors over sodium bromide and iodide: Na2X+, and (X = Br, I). According to the calculations, Na2X+ and triatomic ions have a linear equilibrium configuration of Dh symmetry. Pentaatomic ions can exist in the form of three isomers: linear with Dh symmetry, planar cyclic with С2v symmetry, and bipyramidal with D3h symmetry. At a temperature of ~1000 K, and pentaatomic ions are shown to be present in vapor mainly in the form of linear isomers. The energies and enthalpies of ion molecular reactions with the participation of the above ions are calculated, and the formation enthalpies of the ions are determined, ΔfH°(0 K): 293±2 kJ/mol (Na2Br+), 354±2 kJ/mol (Na2I+), -536±2 kJ/mol -458±2 kJ/mol 24±5 kJ/mol 143±5 kJ/mol -810±5 kJ/mol and -675±5 kJ/mol



7.
STRUCTURE AND SPECTRA OF 1,3-DIOXANES. MICROWAVE SPECTRUM, STRUCTURAL PARAMETERS, AND ab initio CALCULATIONS OF 5-METHYL-1,3-DIOXANE

A. K. Mamleev, L. N. Gunderova, R. V. Galeev, A. A. Shapkin, M. G. Faizullin, A. P. Nikitina, D. V. Shornikov
Keywords: 5-methyl-1, 3-dioxane, microwave spectrum, structure, quantum chemical calculations
Pages: 253-258

Abstract >>
In the microwave spectrum of a 5-methyl-1,3-dioxane sample, the rotational transitions of а and с types with 4 ≤ J ≤ 11 for five isotopomers of a molecule with 13С and 18О isotopes in different sites are identified in a frequency range of 18 GHz to 42 GHz. The spectroscopic constants of isotopomers are found. The substituted rs and effective rо structural parameters of 5-methyl-1,3-dioxane are determined. By the B3PW91/aug-cc-pVDZ density functional method the equilibrium structure of the molecule is calculated. The results of quantum chemical calculations are compared to the experimental data.



8.
ir and Raman spectroscopIC study of the photopolymerization of Langmuir-Blodgett films of acetylenIC acids

I. A. Badmaeva, N. V. Surovtsev, V. K. Malinovskii, L. L. Sveshnikova
Keywords: IR, Raman spectroscopy, Langmuir-Blodgett films, Pb salt of 2-docosynoic acid, photopolymerization
Pages: 259-265

Abstract >>
The UV induced photopolymerization of Langmuir-Blodgett films of lead salt of 2-docosynoic acid (CH3(CH2)18C≡CCOOH) is studied using IR and Raman spectroscopy. It is found that the films are a highly ordered system with trans-configuration of alkyl chains and a bridged complex generated between the carboxyl group and the lead ion. Based on a change in the absorption band intensity in the IR spectra corresponding to the triple bond vibration, the degree of polymerization depending on the irradiation time is determined. In the Raman spectra, a peak at ~1635 cm-1 appears during polymerization, which corresponds to the C=C double bond. The formation of conjugated double bonds in these systems is observed for the first time. During polymerization, methylene chains of molecules retain trans-configuration; the structural ordering of molecules in the film is observed.



9.
Сharacterization and stereochemistry of alkyl 2-chloro- 3-formylacrylates: experimental NMR and theoretical DFT studies

T.M. Barhoumi-slimi, M.T. Ben dhia, M. Nsangou, M.M. El gaied, M.R. Khaddar
Keywords: synthesis, Vilsmeier reaction, stereoisomerism, stereoselectivity, cyclization, NMR, NOEDIFF, B3LYP
Pages: 266-271

Abstract >>
The synthesis of alkyl 2-chloro-3-formylacrylates 1 from alkyl pyruvates was carried out using Vilsmeier reaction. The reaction is highly stereoselective and leads to a 95:5 mixture of Z and E stereoisomers. Both stereoisomers were characterized by 1H and 13C NMR. In CDCl3 solution, the NMR data, particularly the NOEDIFF experiments, show that the major species formed is the Z stereoisomer. Heating compound 1 in THF at reflux afforded the cyclic product 2 in 90 % yield. The interpretation of the experimental data were further supported by DFT/B3LYP calculations.



10.
DENSITY FUNCTIONAL QUANTUM CHEMICAL CALCULATION OF THE X-RAY FLUORESCENCE SPECTRA OF DIMERIC MANGANESE CARBONYL Mn2(CO)10

V. G. Vlasenko, A. T. Shuvaev, I. A. Zarubin
Keywords: X-ray fluorescence spectroscopy, density functional theory, manganese decacarbonyl
Pages: 272-279

Abstract >>
Based on the density functional quantum chemical calculations, the electronic structure of binuclear manganese decacarbonyl Mn2(CO)10 is analyzed. The calculation results are used to interpret the CKα, OKα, MnLα, and X-ray fluorescence spectra of Mn2(CO)10. The theoretical fluorescence spectra constructed using these calculations are in good agreement with the experiment



11.
pROBABILITY OF fLUCTUATIONS IN THE NUMBER OF THE NEAREST NEIGHBOURS IN A HARD-SPHERE LIQUID: PROBABILITIES OF LARGE DEVIATIONS

Y. T. Pavlyukhin
Keywords: hard-sphere fluids, SW fluids, simple fluids
Pages: 280-287

Abstract >>
The paper analyzes the physical implications of the result obtained in the work [1] that a random variable - the number of the nearest neighbors Mλ in a fluid consisting of N hard spheres in the Gibbs canonical ensemble - can be expressed as a sum of N independent and similarly distributed random variables. The mean value of a functional of this random variable determines the free Helmholtz energy of a fluid with the SW interaction potential (hard sphere plus square well). The paper shows that the said property of the random variable Mλ allows one to average this functional using the general methods of the probability theory (the Cramer theorem or the method of large deviations) without expanding it in a perturbation theory series. All the mathematical variables introduced in the proof of the Cramer theorem have a simple physical meaning and are determined by the thermodynamic characteristics of the SW fluid. The conditions of the Cramer theorem are shown to hold in the entire region of the fluid existence except the critical point area.



12.
CONSTRUCTION OF THE MODEL RADIAL DISTRIBUTION CURVES WITH REGARD TO THE FEATURES OF X-Ray DIFFRACTION EXPERIMENT

V. P. Pakharukova, Г‰. M. Moroz, D. A. Zyuzin
Keywords: radial distribution of the electron density, highly dispersed materials, local structure, cerium dioxide
Pages: 288-294

Abstract >>
A method to construct model radial distribution functions (RDFs) fr om the already known structural data is described. The method includes the procedures to calculate termination ripples that always appear on the experimental RDF because of the bounds of the integration lim its in the Fourier transformation of the X-ray scattering curve. The introduction of this procedure increases the accuracy of the comparative RDF method used to elucidate the phase composition of nanodispersed materials and to determine the features of the local structure of the phases as compared to their well crystallized analogues. Cerium dioxide samples with different dispersion exemplify the applicability of this method to determine the features of the local structure.



13.
DEPENDENCE OF THE BOND LENGTH IN MOLECULES AND CRYSTALS ON COORDINATION NUMBERS OF ATOMS

S. S. Batsanov
Keywords: interatomic distance, phase transition, coordination number, bond order
Pages: 295-300

Abstract >>
Two approaches to the description of changes in the bond length in molecules and crystals with changing coordination number of atoms are studied. They are based on a difference or ratio of interatomic distances when the structure is changed. The second approach is shown to yield more accurate results. The change in the interatomic distances in polar compounds has the same character as the change in the ionic radii when coordination numbers are varied.



14.
STRUCTURES OF Ni(II), Pd(II) AND Cu(II) COMPLEXES WITH 1,2-BIS(5,5,5-TRIFLUORO-4-OXOPENT-2-EN-2-AMINO)BENZENE

D. L. Chizhov, E. F. Khmara, P. A. Slepukhin, V. I. Filyakova, V. N. Charushin
Keywords: Ni(II), Pd(II), Cu(II) complexes, 1,2-bis(5,5,5-trifluoro-4-oxopent-2-en-2-amino)benzene, synthesis, X-ray crystallography
Pages: 301-308

Abstract >>
A new fluorine-containing tetradentate ligand 1,2-bis(5,5,5-trifluoro-4-oxopent-2-en-2-amino)benzene and its complexes with Ni(II), Pd(II) and Cu(II) are characterized by single crystal X-ray diffraction. It is found that the enaminoketone fragments of the ligand are identical in bond lengths and angles; they are almost planar, and make the angles of 51.3° to the plane of the benzene ring. The structures of Ni(II), Pd(II), and Cu(II) complexes are similar and have a saddle-shape configuration. The metal ions have square planar coordination and are located almost in the center of the N2O2 square. The average M-N bond lengths are longer than M-О ones by 0.014 Å and 0.034 Å for the Ni(II) and Cu(II) complexes respectively, while in the Pd(II) complex, M-О is longer than M-N by 0.029 Å. The average chelate angles N-M-O in the complexes are: N-Ni-O 95.12°; N-Pd-O 95.68°; N-Cu-O 93.88°.



15.
MOLECULAR AND CRYSTAL STRUCTURE OF A STERICALLY DISTORTED COMPLEX OF Pd(II) WITH 2,9-DIMETHYL-1,10-PHENANTHROLINE [Pd(2,9-Me2-phen)Cl2]

V. N. Demidov, S. A. Simanova, A. I. Savinova, A. V. Zinchenko, T. B. Pakhomova, E. A. Aleksandrova
Keywords: Pd(II) complexes, 2,9-dimethyl-1, 10-phenanthroline, molecular and crystal structure
Pages: 309-315

Abstract >>
A neutral complex of palladium(II) with 2,9-dimethyl-1,10-phenanthroline [Pd(2,9-Me2-phen)Cl2] (goldish orange colored) is examined by single crystal X-ray diffraction. The crystals of [Pd(2,9-Me2-phen)Cl2] are monoclinic and belong to the space group P21/n (a = 11.8670(7) Å, b = 7.8195(5) Å, c = 14.2418(9) Å, β = 92.5450(10)°, Z = 4, V = 1320.25 Å3, R = 0.0289). The complex [Pd(2,9-Me2-phen)Cl2] exhibits a strong distortion of the usual square-planar geometry with a deviation of the central Pd2+ ion and two chloride acido-ligands from the plane of coordinated 2,9-dimethyl-1,10-phenanthroline. The lengths of two Pd-N bonds are slightly different and are 2.058 Å and 2.067 Å, the lengths of the Pd-Cl bonds are equal and are 2.285 Å. 2,9-Me2-phen itself also suffers some distortion of the planar geometry resulting in the boat conformation of the molecule. The crystal structure of the [Pd(2,9-Me2-phen)Cl2] complex is characterized by the presence of π-π stacked dimers arranged in infinite tilted stacks.



16.
CRYSTAL STRUCTURE OF NEW COMPLEXES OF ARSENITOTUNGSTATES WITH TRIANGULAR SULFIDO BRIDGED CLUSTERS: Cs5.6K4.4[{Mo3S4(H2O)5}(H2AsW9O33)2]·19.15H2O AND K6.35(NH4)2.65[{W3S4(H2O)5}(H2AsW9O33)(HAsW9O33AsOH)]·

I. V. Kalinina, М. N. Sokolov, Е. V. Chubarova, Е. V. Peresypkina, V. P. Fedin
Keywords: molybdenum, tungsten, sulfur, chalcogenide cluster, polyoxotungstate, arsenite, X-ray analysis
Pages: 316-321

Abstract >>
The reaction of lacunary arsenitotungstate [AsW9O33]9- with [M3S4(H2O)9]4+ in aqueous solution leads to the formation of the complex [{Mo3S4(H2O)5}(H2AsW9O33)2]10-. X-ray crystal structure analysis of its cesium salt of the composition Cs5.6K4.4[{Mo3S4(H2O)5}(H2AsW9O33)2]·19.15H2O (1) is reported. Similarly, the reaction of [AsW9O33]9- with [W3S4(H2O)9]4+ and NaAsO2 yields [{W3S4(H2O)5}(H2AsW9O33)(HAsW9O33AsOH)]9-. For K6.35(NH4)2.65[{W3S4(H2O)5}(H2AsW9O33)(HAsW9O33AsOH)]·23.7H2O (2) the crystal structure is determined. In both compounds, the {M3S4}4+ cluster cores coordinate one polyoxometalate ion, which functions as a bridging ligand between two metal atoms, and one bidentate polyoxometalate. The other five coordination sites at the cluster core are occupied by water molecules. The complex anions form dimeric associates held together by hydrogen bonds and S…S contacts.



17.
Thermodynamics of sublimation, thermophysical and structural aspects of the molecular crystals of fenamates

A. O. Surov, G. L. Perlovich
Keywords: fenamates, thermodynamics of sublimation, crystal lattice energy, crystal structure, X-ray structural analysis, DSC
Pages: 322-330

Abstract >>
A method of transfer with an inert carrier gas is used to obtain temperature dependences of pressure vapors. The thermodynamic functions of sublimation processes are calculated for seven molecular crystals that belong to the group of non-steroidal anti-inflammatory drugs: diclofenac, niflumic, flufenamic, tolfenamic, mefenamic, N-phenylanthranilic acids, and diphenylamine. Differential scanning calorimetry is applied to study the melting processes of the selected substances. Single crystal X-ray structural literature data are analyzed, and they are compared with the obtained thermodynamic and thermophysical parameters of sublimation and melting processes. A correlation between the values of the enthalpy of sublimation and the melting temperature under standard conditions is found. The effect of different substituents on the crystal lattice energy of this class of compounds is studied.



18.
WAVE MOTION IN MOLECULAR NANOSTRUCTURES: RESULTS OF COMPUTER EXPERIMENTS

L. A. Gribov, V. A. Dement'ev
Keywords: mechanochemistry, wave processes, molecular nanostructures
Pages: 331-336

Abstract >>
The examples of computer experiments on the propagation of wave motion in molecular nanostructures are presented. Some patterns of energy transfer and dissipation inside the molecular structures are discussed.



19.
STRUCTURAL FEATURES OF FINELY DISPERSED PSEUDOBOEHMITE OBTAINED BY A SOL-GEL METHOD

K. I. Shefer, D. A. Yatsenko, S. V. Tsybulya, Г‰. M. Moroz, E. Y. Gerasimov
Keywords: pseudoboehmite, aluminum hydroxide, structure, simulation of diffraction patterns, radial distribution function analysis
Pages: 337-341

Abstract >>
Simulation of diffraction patterns, radial distribution function analysis, and electron microscopy are applied to study the features of the structure of nanosized pseudoboehmite obtained by the sol-gel method. It is found to consist of plate-like particles with a thickness of one lattice constant in the [010] direction. Such a structure of the pseudoboehmite particles results in the absence of the 020 diffraction peak in the diffraction pattern.



20.
SUPRAMOLECULAR ARCHITECTURE OF CATECHOL AND ITS 2:1 COMPLEX WITH DIMETHYLSULFOXIDE

T. M. Polyanskaya, K. A. Khaldoyanidi, A. I. Smolentsev
Keywords: catechol, dihydroxybenzene, dimethylsulfoxide, structure, single crystal, diagram, molecular complex, intermolecular interaction, hydrogen bond
Pages: 342-349

Abstract >>
The crystal structures of catechol (o-dihydroxybenzene) and its 2:1 complex with dimethylsulfoxide are determined at T = 150 K. Crystal dat a: C14H18O5S, M = 298.37, triclinic, space group unit cell parameters: a = 7.7285(13) Е, b = 9.9924(17) Е, c = 10.3188(18) Е, ± = 89.963(4)°, І = 89.968(4)°, і = 69.076(5)°, V = 744.3(2) Е3, Z = 2, Dx = 1.331 g/cm3, R1 = 0.048; C6H6O2, М = 110.11, monoclinic, space group P21/n, a = 9.8206(6) Е, b = 5.5903(3) Е, c = 10.4439(6) Е, І = 114.952(2)°; V = 519.85(5) Е3, Z = 4, Dx= 1.407 g/cm3, R1 = 0.0289. In the 2:1 complex the molecules are joined in a supramolecular ensemble by D-H…A hydrogen bonds (D = O, C; A = O, А); in catechol they are bonded only by O-H…O. The state diagram of the catechol-dimethylsulfoxide system is examined by DTA.



21.
SPIN CROSSOVER - AN UNUSUAL CHEMICAL EQUILIBRIUM

A. B. Koudriavtsev, W. Linert
Keywords: spin crossover, theoretical models
Pages: 350-378

Abstract >>
The nature and theoretical models of spin crossover equilibrium between high-spin and low-spin forms of transition metal complexes are reviewed. Spin crossover compounds are promising materials for information storage and display devices. In the solid state spin crossover is accompanied by several phenomena related to phase transitions. A critical analysis of theoretical models proposed for the explanation of these phenomena is given. The paper mainly focuses on two models that provide for adequate descriptions of the majority of experimental data, viz. the model of the Ising-like Hamiltonian and the molecular statistical model. Descriptions of spin crossover yielded by these two models are formally similar but not identical and they are based on fundamentally different concepts of molecular interactions and ordering, the latter being the origin of the two-step spin crossover. The Ising-like Hamiltonian model approaches spin crossover fr om the point of view of properties of lattices wh ereas the molecular statistical model explains this phenomenon starting from molecules. The latter approach provides for the elucidation of the molecular nature of cooperative phenomena observed in spin crossover which is important for developing the synthetic strategy of promising spin crossover compounds.



22.
ANHARMONIC PROBLEM WITHOUT THE ANHARMONIC POTENTIAL

L. A. Gribov
Keywords: anharmonism, energy matrix, electronic vibrational functions
Pages: 379-382

Abstract >>
Anharmonic effects are shown to be obtained immediately in the statement of a quantum problem as a general electronic vibrational problem in the matrix formulation and without the use of a traditional anharmonic potential. The methods to form the matrix and to calculate all matrix elements are presented.



23.
QUANTUM CHEMICAL STUDY OF THE STRUCTURE OF BICYCLO[2.2.0]HEX-1(4)-ENE AND ITS DIMERS

K. K. Kalninsh, S. G. Semenov
Keywords: strained polycyclic hydrocarbons, structure, RHF, B3LYP, PBE0, 6-311G**
Pages: 383-386

Abstract >>
The RHF, B3LYP, and PBE0/6-311G** quantum chemical methods are used to determine the point symmetry group and the equilibrium structure of bicyclo[2.2.0]hex-1(4)-ene (I, D2h), its two stable dimers (tricyclo[4.2.2.22,5]dodeca-1.5-diene (II, D2h) and 2,5-dimethylenetricyclo[4.2.2.01,6]decane (III, C2)), and pentacyclo [4.2.2.22,5]dodecane (IV, D2) that is a hypothetical intermediate in the dimerization reaction of the molecules of I. The relation of total energies is obtained with regard to zero-point vibrations: E(III) < E(II) ? E(IV) ? 2E(I).



24.
PHASE OF THE COMPOSITION CaBaLaCu2FeO7.5: SYNTHESIS, STRUCTURE, MГ–SSBAUER SPECTRA

V. G. Bekeshev, Y. N. Kil'yanov, R. A. Stukan
Keywords: high-temperature superconductors, systems 123, 57Fe M?ssbauer spectroscopy, powder X-ray diffraction analysis
Pages: 387-390

Abstract >>
The phase of the composition CaBaLaCu2FeO7.5 is synthesized from the previously obtained CaCuO2, La2Cu2O5, and BaFeO2 double oxides enriched up to 14.7% in 57Fe. The phase has the orthorhombic crystal system with the unit cell parameters as follows: a = 0.3882(3) nm, b = 0.3911(3) nm, c = 1.1823(8) nm. Based on the Mössbauer spectra analysis, the conclusion is drawn that iron atoms occupy only Cu(1) sites in the lattice, while more than 90% of them are in the Fe4+ valence state (80% of these atoms have the tetragonal pyramidal coordination).



25.
NEW SUPRAMOLECULAR ADDUCTS OF CHLOROAQUACOMPLEXES [M3(Ој3-S)S3-xSexCly(H2O)9-y](4-y)+ (M = Mo, W) WITH CUCURBIT[6]URIL

P. A. Abramov, А. L. Gushchin, М. N. Sokolov, V. P. Fedin
Keywords: clusters, sulfur, selenium, chloroaquacomplexes, cucurbituril, supramolecular complexes, crystal structure
Pages: 391-395

Abstract >>
New supramolecular adducts of cucurbit[6]uril with triangular cluster chloroaquacomplexes of Mo and W with mixed sulfido-selenido bridging ligands, {[W3S3Se(H2O)7Cl2]2(C36H36N24O12)}Cl2·15H2O (1), {[W3S1.5Se2.5Cl1.5(H2O)7.5]2(C36H36N24O12)}Cl5·18.5H2O (2), and {[Mo3SSe3(H2O)7.5Cl1.5]2×(C36H36N24O12)}Cl5·11H2O (3) are obtained treating the mixture of products in Mo-S-Se-Br and W-S-Se-Br systems, isolated, and structurally characterized. In all compounds, the supramolecular structure is based on hydrogen bonded associates of cucurbit[6]uril molecule with two cluster cations.



26.
Zinc Citrate with Alkali Metal and Ammonium Cations: Crystal Structure of K4[Zn(Citrate)2]

Y. Kim, H.G. Koo, D.H. Shin, L.O. Park, J.H. Lee, H.G. Jang, C. Kim
Keywords: zinc citrate, synthesis, crystal structure, citric acid
Pages: 396-398

Abstract >>
In the crystal of K4[Zn(Citrate)2], two citrate anions coordinate Zn(II) cation with octahedral geometry in the [Zn(Citrate)2]4- complex anion, and the charge is balanced by four potassium ions. Crystal dat a: monoclinic, P21/c, a = 8.502(2) Е, b = 13.210(3) Е, c = 8.942(2) Е, І == 113.132(4)°, V = 923.5(4) Е3, Z = 2, R = 0.0229.



27.
CRYSTAL STRUCTURES AND LUMINESCENCE OF TWO ZINC(II) COMPLEXES WITH BENZIMIDAZOLE LIGANDS

S.B. Miao, B.M. Ji, D.S. Deng, C. Xu, N. Ma
Keywords: crystal structure, fluorescence, dimethylformamide
Pages: 399-403

Abstract >>
Two new zinc(II) complexes have been synthesized and studied by single crystal X-ray diffraction method: [Zn(L1)Cl2]·2DMF (1) and [Zn(L2)Cl2]·DMF (2) (L1 = 3,3′-bis(2-benzimidazolyl)-2,2′-dipyridine, L2 = 3,3′-bis[2-bis(2-ethylbenzimidazolyl)]-2,2′-dipyridine). Compound 1 is monoclinic, C2/c, a = 23.142(3), b = 11.845(1), c = 14.735(3) Å; compound 2 is orthorhombic, C2221, a = 12.140(7), b = 16.283(9), c = 16.51(1) Å. In both compounds, Zn(II) cations are coordinated by two chlorine atoms and two benzimidazole nitrogen atoms in a slightly distorted tetrahedron fashion. Structural features responsible for fluorescent properties of the complexes are discussed.



28.
MOLECULAR AND CRYSTAL STRUCTURE OF 2-(2-p-TOLYLOXYETHOXY)ETHYLCHLOROACETATE

L. E. Foss, Y. K. Voronina, P. I. Gryaznov, A. T. Gubaidullin, P. S. Fakhretdinov, I. A. Litvinov, G. V. Romanov
Keywords: 2-(2-p-tolyloxyethoxy)ethylchloroacetate, crystal and molecular structure, X-ray diffraction analysis
Pages: 404-406

Abstract >>
2-(2-p-Tolyloxyethoxy)ethylchloroacetate is synthesized and its single crystal X-ray diffraction analysis is performed.



29.
MOLECULAR STRUCTURE OF METHYL-10,14,19,19- TETRAMETHYL-4-OXO-20-OXAHEXACYCLO [15.3.1.16.18.06.15.09.14017.21]DOCOSANE-10-CARBOXYLATE

I. E. Smirnova, E. V. Tretyakova, O. B. Kazakova
Keywords: methyl-10,14,19,19-tetramethyl-4-oxo-20-oxahexacyclo[15.3.1.16.18.06.15.09.14017.21]docosane-10-carboxylate,, synthesis, X-ray diffraction analysis
Pages: 407-409

Abstract >>
The synthesis of methyl-10,14,19,19-tetramethyl-4-oxo-20-oxahexacyclo[15.3.1.16.18.06.15.09.14017.21] docosane-10-carboxylate III is performed and its molecular structure is determined. Compound III С27H40O4 crystallizes in the monoclinic system with the cell parameters as follows: а = 12.8081(11) Å, b = 7.0384(6) Å, c = 12.8904(12) Å, β = 105.828(2)°, P21 space group, Z = 2, d = 1.273 mg/m3.



30.
Crystal Structure of 2-(6-chloro-4-(p-tolylamino)pyrido[3,2-d]pyrimidin-1-ium-1-yl)acetate Oxonium Bromide

L. Shen, F.L. Zhang
Keywords: pyridopyrimidine derivatives, quaternary ammonium salts, crystal structure, hydrogen bond
Pages: 410-412

Abstract >>
The crystals of 2-(6-chloro-4-(p-tolylamino)pyrido[3,2-d]pyrimidin-1-ium-1-yl)acetate (zwitterionic form) oxonium bromide, C16H13ClN4O2·Br-·H3O+ (I) were prepared and studied by single-crystal X-ray diffraction method. The compound crystallizes in the triclinic space group P-1 with a = 8.3121(8), b = 9.3885(8), c = 13.2903(12) Å, α = 106.788(2), β = 95.204(3), γ = 110.871(2)°, V = 905.81(14) Å3, Z = 2; final R = 0.053, wR2 = 0.150. It is interesting that methylene C in the BrCH2COOH molecule binds to the N1 of the pyrimidine ring. In the crystal studied, two neighboring organic molecules are connected by hydrogen bonds through carboxylate oxygen, oxonium and bromide ions to form a dimer.