The crystallographic analysis of Bi2S3, CuPbBi5S9, CuPbBi3S6, CuPbBiS3 compounds, representing a series with a successive replacement of a part of Bi atoms by Pb+Cu shows that they are characterized by a stable combination of a pseudo-tetragonal cation framework with a pseudo-hexagonal anion one, which is common for all structures, within orthorhombic unit cells with n sizes of 11.2 , 4, and 11.5. The Bi2S3 cation framework is retained for heavy Bi+Pb, and additional light Cu fill the available vacant sites without changing its geometry but varying the crystallographic symmetry within the orthorhombic crystal symmetry and unit cells of n standard blocks (11,2x4x11,5 Å3).
I. R. Shein, M. V. Kuznetsov, A. N. Enyashin
Institute of Solid State Chemistry, Ural Branch, Russian Academy of Sciences, Ekaterinburg, Russia
Keywords: графен, графит, точечные дефекты, метод функционала электронной плотности, молекулярная динамика, graphene, graphite, point defects, density functional theory, molecular dynamics
Point defect formation within graphene and ultra-thin graphite films is considered by means of molecular dynamics simulations in the framework of density functional tight-binding approach. The barrier energy for vacancy formation is estimated and two types of defect formation are revealed.
I.S. Vinogradova1, O.V. Falaleev2 1Siberian State Technological University, Krasnoyarsk, Russia 2Kirensky Institute of Physics, Siberian Branch, Russian Academy of Sciences, Krasnoyarsk, Russia
Keywords: Н магнитно-резонансная микротомография
, семена фасоли, набухание семян, распределение воды, Н magnetic resonance microtomography
, Carolina beans, bean swelling. water distribution
The results of the 1Н magnetic resonance microtomography study of large Carolina beans during their swelling in water are presented. The studies are performed using two-dimensional longitudinal tomographic sections. Channels through which water incomes to a swelling beam are determined and the heterogeneity of its distribution inside the bean is shown.
N. Ouerfelli1,2, H. Chebbi1,3, Zid M. Faouzi1 1Universite de Tunis El Manar, El Manar II, Tunis, Tunisia 2Universite de Tunis Carthage, Bizerte, Tunisia 3Universite de Monastir, Monastir, Tunisia
Keywords: iron arsenate-oxalate, synthesis, single crystal X-ray diffraction, crystal structure
A new open-framework structure of iron arsenate-oxalate (NH4)3K3[Fe2(HAsO4)2(C2O4)4]x2H2O (I) is synthesized by slow evaporation and structurally characterized by single crystal X-ray diffraction methods. It crystallizes in the triclinic space group P (No . 2), with a = 10.154(4) Å, b = 10.430(4) Å, c = 15.085(7) Å, a = 96.81(3)°, b = 105.04(43)°, g = 93.93(3)°, V = 1523.7(11) Å3 and Z = 2. Its crystal structure consists of two crystallographically independent bishydrogenarsenato tetraoxalato diiron(III) anions, both located on centres of inversion, while the potassium and ammonium cations and water molecules are located in general positions.These moieties are connected through N - H…O and O - H…O hydrogen bonds to form infinity of layers parallel to the (101) plane, thus leading to a two-dimensional open framework.
A new complex of copper (II) with 3-(2-hydroxy-3-sulfo-5-nitrophenylazo)-pentadione-2,4 (HL) is synthesized and analyzed by single crystal XRD. The crystals are monoclinic: a = 7.7563(4) Å, b = 24.0157(12) Å, c = 24.6353(13) Å, b = 91.9490(10) °, V = 4586.2(4) Å3, space group P 21/ c , Z = 2, ρcalc = 1.713 g/cm3, R = 0.0695. The copper atom environment is formed by three oxygen atoms, the nitrogen atom of the tetradentate ligand, and the oxygen atom of a water molecule.
M.A. Kinzhalov, A.A. Zolotarev, V.P. Boyarskii
St. Petersburg State University, St. Petersburg, Russia
Keywords: комплексы палладия, изоцианиды, palladium complexes, isocyanides
The interaction between PdCl2(CH3CN)2 and 2,4,6-Me3C6H2NC (MesNC) proceeds with the substitution of acetonitrile ligands and leads to the synthesis of a cis -[PdCl2(MesNC)2] complex. The structure of this compound is determined by single crystal X-ray diffraction. The complex has a slightly distorted square-planar structure of the metal center with two cis -positioned isocyanide ligands. The triple bonds in both CN isocyanide fragments have lengths similar to the lengths of the corresponding bonds in other isocyanide complexes. In the structure, the cis -[PdCl2(MesNC)2] complexes are bound by weak С-H⋯Cl hydrogen bonds and p-stacking interactions.
By heating of an aqueous solution of zinc(II) or cobalt(II) acetates, 4,4-bipyridyl (bpy), and S -3,3-dimethyl hydroxypropionic acid (H2dml) two homochiral coordination polymers [Zn(H2O)(bpy)(Hdml)](CH3COO)2H2O (1) and [Co(H2O)(bpy)(Hdml)2] (2) are obtained. The crystal structure is determined by single crystal X-ray diffraction. Compound 1 has a layered structure and compound 2 has a chain structure.
M. Bouchouit1, A. Bouraiou1, S. Bouacida1,2, A. Belfaitah1, H. Merazig1 1Universite des freres Mentouri, Constantine, 25000, Algerie 2Universite Oum El Bouaghi, 04000 Oum El Bouaghi, Algerie
Keywords: X-ray crystallographic analysis, imidazole, cobalt complex, crystal structure
The preparation of a cobalt(II) chloride complex with a N-donor ligand 1-benzyl-5-methyl-1 H -imidazole of formula [CoCl2(1-benzyl-5-methyl-1 H -imidazole)2] is described. The isolated complex was characterized by UV, IR spectroscopy and crystallographic studies. Single crystal X-ray diffraction analysis of the complex reveals its monomeric tetra-coordinated nature. The coordination polyhedron around the cobalt center can be described as a quasi-regular tetrahedron. The Co-N distances for this compound are 2.0111(17) Å and 2.0118(17) Å, while the Co-Cl distances are 2.2582(7) Å and 2.2549(7) Å. The crystal packing can be described as layers parallel to (101) plane alternating along the b axis, and it is stabilized by p-p stacking between the imidazole and phenyl rings. The shortest centroid-centroid distance is 3.6002(14) Å.
Y.-M. Cui1, D. Yang1, W. Guo2, Q. Wang1, P. Zhang1 1Wuhan Textile University, Wuhan 430073, P. R. China 2Chinese Sturgeon Institute, China Three Gorges Corporation, Yichang 443100, P. R. China
Keywords: hydrazone ligands, oxovanadium(V) complex, self-assembly, substituent effects, crystal structure
An oxo-bridged dinuclear oxovanadium(V) complex, [V2O2(m-O)(L1)2] (1) [H2L1 = 3-nitrobenzoic acid (1-methyl-3-oxobutylidene)hydrazide], and a mononuclear oxovanadium(V) complex, [VO(OMe)(L2)] (2) [H2L2 = 3-hydroxynaphthalene-2-carboxylic acid (1-methyl-3-oxobutylidene)hydrazide], were prepared by the reactions of [VO(acac)2] with H2L1 and H2L2, respectively, in methanol. Both complexes were characterized by elemental analysis, IR spectra, and single crystal X-ray crystallography. The crystal of 1 crystallizes in the monoclinic space group P 2/ n , with a = 13.116(3), b = 7.597(2), c = 13.927(2) Å, b = 104.851(2)°, V = 1341.4(5) Å3, Z = 2. The crystal of 2 crystallizes in the triclinic space group P , with a = 7.897(2), b = 9.690(2), c = 11.576(3) Å, a = 86.405(2)°, b = 70.597(2)°, g = 85.991(2)°, V = 832.7(3) Å3, Z = 2. The V atoms in the complexes have square pyramidal environment. The substituent groups attached to the aromatic rings can influence the self-assembly of the complexes.
Q.-S. Ye1, M.-J. Xie2, X.-N. Li3, W.-P. Liu1, J. Yu1, Q.-W. Chang1, J. Jiang1, C.-X. Yan1, J. Li1 1Kunming Institute of Precious Metals, Kunming 650106, P. R. China 2Yunnan University, Kunming 650031, P. R. China 3Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, P. R. China
Keywords: platinum, amide, ammine, crystal structure, synthesis
Di-m-amido-bis[diammineplatinum(II)] nitrate (1) was synthesized as a byproduct during preparation of tetraammineplatinum(II) nitrate. One possible pathway to produce 1 is that [(H3N)2Pt(m-OH)2Pt(NH3)2](NO3)2, a well-known complex forming on treatment of cis -Pt(NH3)2I2 with AgNO3, reacts with aqueous ammonia. The other possible pathway involves deprotonation of [Pt(NH3)4](NO3)2 to form monomeric Pt(NH3)3(NH2)NO3 followed by elimination of NH3. Crystals of 1 (from water) are monoclinic ( C 2/ c ) with a = 16.834(2) Å, b = 10.573(1) Å, c = 7.415(1) Å, b = 114.846(1)°, and Z = 4. The cationic portion consists of two symmetrical square-planar Pt centers with the inversion center at the midpoint of the Pt(1)⋯Pt(1A) vector. The Pt(II) ion is coordinated by four N atoms from two ammonia molecules and two bridging amido groups affording a slightly distorted square. The molecules are stacked in such a way that the planes of coordination squares turn out to be parallel to each other with a distance of 3.501 Å. Intermolecular Pt-H interaction between the m-NH2 hydrogens and the platinum(II) centers of the adjacent molecule are observed.
