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1.
S. P. Khranenko E. A. Shusharina S. A. Gromilov S. V. Korenev 《Journal of Structural Chemistry》2011,52(3):544-549
Crystal structures of two modifications of a binuclear Pd2(μ-ac)2(acac)2 complex are studied at 150 K and 297 K (ac = acetate; acac = acetylacetonate). It is demonstrated that in both cases, the packing of the complexes can be considered as pseudohexagonal, the molecules forming infinite chains by interactions between chelate rings with the shortest contacts Pd...C γ ~ 3.3 Å. 相似文献
2.
Abstract
Three novel lanthanide-organic frameworks: [Ln2(pyba)3(μ3-OH)2(μ2-OH)(H2O)] n (Ln = Er (1), Y (2), Dy (3) Hpyba = 4-pyridin-4-yl-benzoic acid) have been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. Structure analysis shows that each {Ln4(μ3-OH)4(μ2-OH)2} cluster units interconnect to form 1-D chains, which are further linked by π–π interactions to make a 3-D supramolecular network structure. Furthermore, the IR, PXRD and TGA of compounds 1–3 were also studied. 相似文献3.
Ray L. Frost Sara J. Palmer Ross E. Pogson 《Journal of Thermal Analysis and Calorimetry》2012,107(3):905-909
Thermogravimetry combined with evolved gas mass spectrometry has been used to characterise the mineral crandallite CaAl3(PO4)2(OH)5·(H2O) and to ascertain the thermal stability of this ‘cave’ mineral. X-ray diffraction proves the presence of the mineral and
identifies the products of the thermal decomposition. The mineral crandallite is formed through the reaction of calcite with
bat guano. Thermal analysis shows that the mineral starts to decompose through dehydration at low temperatures at around 139 °C
and the dehydroxylation occurs over the temperature range 200–700 °C with loss of the OH units. The critical temperature for
OH loss is around 416 °C and above this temperature the mineral structure is altered. Some minor loss of carbonate impurity
occurs at 788 °C. This study shows the mineral is unstable above 139 °C. This temperature is well above the temperature in
the caves of 15 °C maximum. A chemical reaction for the synthesis of crandallite is offered and the mechanism for the thermal
decomposition is given. 相似文献
4.
A. V. Rassolov P. V. Markov G. O. Bragina G. N. Baeva D. S. Krivoruchenko I. S. Mashkovskii I. A. Yakushev M. N. Vargaftik A. Yu. Stakheev 《Kinetics and Catalysis》2016,57(6):859-865
The formation of Pd–Ag nanoparticles deposited from the heterobimetallic acetate complex PdAg2(OAc)4(HOAc)4 on α-Al2O3, γ-Al2O3, and MgAl2O4 has been investigated by high-resolution trans-mission electron microscopy, temperature-programmed reduction, and IR spectroscopy of adsorbed CO. The reduction of PdAg2(OAc)4(HOAc)4 supported on γ-Al2O3 and MgAl2O4 takes place in two steps (at 15–245 and 290–550°C) and yields Pd–Ag particles whose average size is 6–7 nm. The reduction of the Pd–Ag catalyst supported on α-Al2O3 occurs in a much narrower temperature range (15–200°C) and yields larger nanoparticles (~10–20 nm). The formation of Pd–Ag alloy nanoparticles in all of the samples is demonstrated by IR spectroscopy of adsorbed CO, which indicates a marked weakening of the absorption band of the bridged form of adsorbed carbon monoxide and a >30-cm–1 bathochromic shift of the linear adsorbed CO band. IR spectroscopic data for PdAg2/α-Al2O3 suggest that Pd in this sample occurs as isolated atoms on the surface of bimetallic nanoparticles, as is indicated by the almost complete absence of bridged adsorbed CO bands and by a significant weakening of the Pd–CO bond relative to the same bond in the bimetallic samples based on γ-Al2O3 and MgAl2O4 and in the monometallic reference sample Pd/γ-Al2O3. 相似文献
5.
A complex of Erbium perchloric acid coordinated with l-aspartic acid and imidazole, Er2(Asp)2(Im)8(ClO4)6·10H2O was synthesized for the first time. It was characterized by IR and elements analysis. The heat capacity and thermodynamic
properties of the complex were studied with an adiabatic calorimeter (AC) from 80 to 390 K and differential scanning calorimetry
(DSC) from 100 to 300 K. Glass transition and phase transition were discovered at 220.45 and 246.15 K, respectively. The glass
transition was interpreted as a freezing-in phenomenon of the reorientational motion of ClO4− ions and the phase transition was attributed to the orientational order/disorder process of ClO4− ions. The thermodynamic functions [H
T
− H
298.15] and [S
T
− S
298.15] were derived in the temperature range from 80 to 390 K with temperature interval of 5 K. Thermal decomposition behavior
of the complex in nitrogen atmosphere was studied by thermogravimetric (TG) analysis and differential scanning calorimetry
(DSC). 相似文献
6.
L. B. Serezhkina E. V. Peresypkina A. V. Virovets I. V. Medrish D. V. Pushkin 《Russian Journal of Inorganic Chemistry》2009,54(10):1577-1580
Single crystals of Cs[(UO2)2(C2O4)2(OH)] · H2O were synthesized and structurally studied using X-ray diffraction. The compound crystallizes in monoclinic space group P21/m, Z = 2, with the unit cell parameters a = 5.5032(4) Å, b = 13.5577(8) Å, c = 9.5859(8) Å, β = 97.012(3)°, V = 709.86(9) Å3, R = 0.0444. The main building units of crystals are [(UO2)2(C2O4)2(OH)]? layers of the A2K 2 02 M2 (A = UO 2 2+ , K02 = C2O 4 2? , and M2 = OH?) crystal-chemical family. Uranium-containing layers are linked into a three-dimensional framework via electrostatic interactions with outer-sphere cations and hydrogen bonds with water molecules. 相似文献
7.
L. T. Denisova A. D. Izotov Yu. F. Kargin V. M. Denisov N. A. Galiakhmetova 《Doklady Physical Chemistry》2017,477(1):205-207
The oxide compound Pb8La2(GeO4)4(VO4)2 with an apatite structure has been synthesized by a ceramic method. The effect of temperature on the molar hear capacity of polycrystalline samples in the temperature range 320–1000 K has been studied by differential scanning calorimetry. The results have been used to calculate the thermodynamic functions of the synthesized compound. 相似文献
8.
Zh. V. Akhmerkina E. V. Peresypkina A. V. Virovets L. B. Serezhkina 《Russian Journal of Inorganic Chemistry》2008,53(9):1396-1400
Single crystals of Ba3[UO2(C2O4)2(NCS)]2 · 9H2O are synthesized and studied by X-ray diffraction. The crystals are orthorhombic, space group Fddd, Z = 16, and the unit cell parameters are a = 16.253(3) Å, b = 22.245(3) Å, c = 39.031(6) Å. The main crystal structural units are mononuclear complex groups [UO2(C2O4)2NCS]3? of the crystal-chemical family (AB 2 01 M1 (A = UO 2 2+ , B01 = C2O 4 2? , M1 = NCS?) of the uranyl complexes linked into a three-dimensional framework by electrostatic interactions and hydrogen bonds involving oxalate ions and water molecules. 相似文献
9.
P. N. Bourosh O. A. Bologa M. Gdaniec Yu. A. Simonov N. V. Gerbeleu 《Journal of Structural Chemistry》2005,46(3):488-493
A new Co(III) complex of 1,2-cyclohexanedionedioxime and thiocarbamide with an SO 4 2? anion and solvation water molecules in the outer sphere has been synthesized and its structure has been defined. Orthorhombic crystals, a = 11.659(2) Å, b = 26.448(5) Å, c = 30.142(6) Å, V = 9295(3) Å 3, Z = 8, dcalc = 1.599 g/cm3, space group Pbca; final R index is 0.0578 for 8221 reflections with I > 2σ(I). In the octahedral Co(III) complex, two 1,2-cyclohexanedionedioxime residues lie in the equatorial plane, while two thiocarbamide molecules are in the axial plane. Intramolecular bonds: N-H…O and O-H…O type hydrogen bonds and π-π interactions that stabilize the complex cations. In crystal, the components are linked by N-H…O and O-H…O hydrogen bonds into a 3D framework. 相似文献
10.
I. V. Medrish E. V. Peresypkina A. V. Virovets L. B. Serezhkina 《Russian Journal of Coordination Chemistry》2008,34(8):629-634
The single crystals of Rb2[(UO2)2(C2O4)2(SeO4)] · 1.33H2O were synthesized and studied by X-ray diffraction. The crystals are monoclinic, space group P21/m, Z= 2, the unit cell parameters: a = 5.6537(8), b = 18.736(3), c = 9.4535(15) Å, β = 98.440(5)°, V = 990.6(3) Å3, R 1 = 0.0506. The main structural units of the crystal are infinite layers of [(UO2)2(C2O4)2(SeO4)]2?, corresponding to the crystal chemical group A2K 2 02 B2 (A = UO 2 2+ , K02 = C2O 4 2? , B2 = SeO 4 2? ) of uranyl complexes. The uranium-containing layers are united into a three-dimensional framework through the electrostatic interactions with the outer-sphere rubidium ions and the hydrogen bonding system involving the outer-sphere water molecules. 相似文献
11.
N. A. Sanina S. M. Aldoshin T. N. Rudneva N. I. Golovina G. V. Shilov Yu. M. Shul’ga V. M. Martynenko N. S. Ovanesyan 《Russian Journal of Coordination Chemistry》2005,31(5):301-306
Binuclear iron nitrosyl complex Na2[Fe2(S2O3)2(NO)4] · 4H2O (I) was synthesized by the reaction of iron(II) sulfate with sodium thiosulfate in the flow of NO gas. According to X-ray diffraction data, the [Fe2(S2O3)2(NO)4]2– anion has binuclear centrosymmetric structure with Fe atoms bonded by the µ-S atoms of thiosulfate groups. The isomeric shift for complex I =0.168(1) mm/s and quadrupole splitting E
Q
=1.288 mm/s at T=80 K. When heated, complex I transforms to Na2[Fe2(S2O3)2(NO)4] (II), whose unit cell parameters found by X-ray diffraction method differ from those of complex I. The process of transformation of I to II was studied by calorimetric method. Complex I transforms to complex II without chemical decomposition, which was confirmed by IR and mass spectroscopy data.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 5, 2005, pp. 323–328.Original Russian Text Copyright © 2005 by Sanina, Aldoshin, Rudneva, Golovina, Shilov, Shulga, Martynenko, Ovanesyan. 相似文献
12.
A. A. Kashaev I. V. Rozhdestvenskaya I. I. Bannova A. N. Sapozhnikov O. D. Glebova 《Journal of Structural Chemistry》2008,49(4):708-711
Four structural models of volborthite Cu3(OH)2(V2O7)·2H2O (a = 10.646(2) Å, b = 5.867(1) Å, c = 14.432(2) Å, β = 95.19(1)°, V = 897.7(5) Å3, Z = 4, R/R w = 0.038/0.046) calculated in the space groups determined from the systematic absences are compared. Based on the structure balance and the similarity of constituting polyhedra, values of the R factor, and isotropic thermal parameters, the space group Ia is found to be preferable, which is the only possible asymmetric and uniform variant. Hydrogen atoms of OH-groups, oxygen atoms and, partially, hydrogen atoms of water are localized. 相似文献
13.
Triethylamine reacts with aqueous zinc acetate and the product of its thermolysis in the presence of benzoic acid to yield
the complexes [Zn7(μ4-O)(μ-OOCMe)10][η-OC(Me)OHNEt3]2 (1) and [Zn2(μOOCPh)4][η-OC(Me)OHNEt3]2 (2), respectively. The reactions of 1 and 2 with 3,5-dimethylpyrazole at room temperature in benzene yield pyrazolate-bridged binuclear complexes Zn2(μdmpz)2(Hdmpz)2(OOCR)2 (R = Me (3), Ph (4)). The structures of complexes 1–4 have been determined by X-ray crystallography. 相似文献
14.
I. P. Malkerova A. S. Alikhanyan I. G. Fomina Zh. V. Dobrokhotova 《Russian Journal of Inorganic Chemistry》2010,55(1):53-55
Sublimation of europium pivalate binuclear complexes Eu2(Piv)6 and [Eu2(Piv)6 · (Phen)2] (Piv = (CH3)3CCOO, Phen = C12H8N2) in the temperature range of 383–660 K is studied by the Knudsen effusion method with mass-spectrometric analysis of the
gas phase. The vaporization of Eu2(Piv)6 is shown to be accompanied by polymerization and the formation of Eu2(Piv)6 and Eu4(Piv)12 molecules. The saturated vapor over the mixed-ligand complex of europium pivalate with o-phenanthroline consists of Phen, Eu2(Piv)6, and Eu4(Piv)12 molecules. The partial pressures of the gas components, as well as the standard enthalpies of sublimation and dissociation
of the reaction proceeding with removal of phenanthroline have been determined. 相似文献
15.
The structure of tris-complexes Y(MDA)3, Y(HFA)3 and their dimeric forms of Y2(MDA)6 and Y2(HFA)6 (MDA = C3O2H3; HFA = C5O2F6H) are investigated by the non-empirical Hartree-Fock method and also taking into account the correlation of electrons in the context of density functional theory (DFT/B3LYP) using effective pseudopotentials to describe the atomic core and double-exponential valence basis sets supplemented with polarization functions. For the first time the structure of Y(HFA)3, Y2(MDA)6, and Y2(HFA)6 molecules has been studied in this work. The equilibrium configuration of Y(HFA)3 monomer is a structure with a coordination polyhedron of [YO6] that has the form of a distorted octahedron with planar chelate fragments and CF3 substituents in which the C-F bond screens the C-C bond in the chelate fragment. The barrier of the internal rotation of one CF3 group is ~3.0 kJ/mole (DFT/B3LYP). It is shown that rotations of CF3 groups in Y(HFA)3 molecule could be considered as mutually independent. The structures of C 1 and C 2 symmetry are the equilibrium configurations of Y2(MDA)6 and Y2(HFA)6 dimers respectively (DFT/B3LYP). The structure of the coordination polyhedron of [Y2O12] in C 1 and C 2 symmetry configurations can be represented as a combination of eight-and seven-coordinated polyhedra or two seven-coordinated polyhedra respectively. The energy stability of dimeric complexes is studied. According to DFT/B3LYP data, the dimerization energy equals ?80.8 kJ/mole and ?62.3 kJ/mole for Y2(MDA)6 and Y2(HFA)6 respectively. The force fields and frequencies of normal vibrations are calculated for the equilibrium configurations. The trends of changes in the vibrational spectra in Y(MDA)3→Y(HFA)3 and monomer→dimer transitions are discussed. The comparison with available experimental data is made. 相似文献
16.
D. A. Bashirov N. A. Pushkarevsky A. V. Vitovets O. Fuhr S. N. Konchenko 《Russian Journal of Coordination Chemistry》2008,34(10):739-749
In the reaction of Na2Se with [Fe(CO)5] in isopropanol with subsequent acidification with HCl, which is used to synthesize [(μ-H)2Fe3(μ3-Se)(CO)9] (II), the cluster [(μ-H)2Fe5(μ3-Se)2(CO)14] (I) was detected. In assumption that compound I could serve as a suitable synthon for preparing the bulky heterometallic clusters, its reactions with the Rh-containing complexes were studied. The reaction of I with [Rh(CO)2Cp*] (Cp* is pentamethylcyclopentadienyl) was found to give a mixture of the products. The main reaction products were isolated and their structures were determined: [Fe2Rh(μ3-Se)2(CO)6Cp*], [Fe2Rh(μ3-Se)(μ3-CO)(CO)6Cp*], [FeRh2(μ3-Se)(μ-CO)(CO)3Cp 2 * ], [Fe2Rh2(μ4-Se)(μ-CO)4(CO)2Cp 2 * ]. Potassium hydride treatment of II with subsequent addition of [Cp*Rh(CH3CN)3](CF3SO3)2 leads to the well-known cluster complex [Fe3Rh(μ4-Se)(CO)9Cp*]. A set of the reaction products indicates that the {Fe5Se2} core cannot be used as one-piece “building block” in the synthesis of heterometallic clusters. 相似文献
17.
A novel Salen-type bisoxime ligand, 6,6′-dimethoxy-2,2′-[(1,4-butylene)dioxybis(nitrilomethylidyne)]diphenol (H2L) and its tetranuclear Cu(II) complex, [Cu4L2(pic)4(H2O)2]·2H2O, have been synthesized and characterized by elemental analyses, IR, TG-DTA and 1H-NMR etc. The X-ray crystal structure of the complex reveals that formation of a tetranuclear structure, which consists of four copper(II)
atoms, two pentadentate L2−units, four picratols, two coordinated water molecules and two crystallizing water molecules. Around four copper ions are
all octahedral geometries. It was demonstrated that the picratols in the tetranuclear copper(II) complex show a novel tridentate
coordination mode. 相似文献
18.
I. A. Baidina V. D. Il’yashevich V. F. Malakhov A. V. Belyaev 《Journal of Structural Chemistry》2007,48(5):973-976
The complex Na3(NH4)2[Ir(SO3)2Cl4]·4H2O was examined with single crystal X-ray diffraction and IR spectroscopy. Crystal data: a = 7.3144(4) Å, b = 10.0698(5) Å, c = 12.3748(6) Å, β = 106.203(1)°, V = 875.26(8) Å3, space group P21/c, Z = 2, d calc = 2.547 g/cm3. In the complex anion two trans SO 3 2? groups are coordinated to iridium through the S atom. The splitting of O-H bending vibrations of crystallization water molecules and N-H ones of the ammonium cation is considered in the context of different types of interactions with the closest neighbors in the structure. 相似文献
19.
S. E. Nefedov I. V. Pruss E. V. Perova G. L. Kamalov 《Russian Journal of Inorganic Chemistry》2009,54(11):1713-1729
We discovered that reactions of hydrous cobalt and zinc acetates with 3,5-dimethylpyrazole (Hdmpz) in boiling xylene or toluene
or upon the thermolysis of solid precursors (150°C) yield trinuclear pyrazolate-bridged complexes M3 (μ-dmpz)4(Hdmpz)2 (OOCMe)2(M = Zn or Co). Depending on the crystallization conditions, these complexes contain various solvating molecules (benzene,
toluene, or Hdmpz), which influences the character of intramolecular and intermolecular hydrogen bonding, as shown by X-ray
crystallography. 相似文献
20.
V. N. Serezhkin A. G. Verevkin O. P. Smirnov V. P. Plakhtii 《Russian Journal of Inorganic Chemistry》2010,55(10):1600-1606
A powder of deuterated rubidium diselenatouranylate dihydrate Rb2UO2(SeO4)2 · 2D2O has been studied by neutron diffraction. The compound is orthorhombic, space group Pna21, with the following unit cell parameters: a = 13.654(2) Å, b = 11.863(2) Å, c = 7.625(1) Å, Z = 4, R F = 3.77, R I = 6.12, and χ2 = 2.21. Basic structure units are [UO2(SeO4)2 · D2O]2? layers belonging to the AB 2 2 M1 crystal-chemical group (A = UO 2 2+ , B2 = SeO 4 2? , M1 = D2O) of uranyl complexes. The hydrogen atoms if the water molecules involved in the layer form intralayer hydrogen bonds with the terminal oxygen atoms of selenate ions. The outer-sphere water molecules are coordinated to the rubidium ions and are involved in hydrogen bonding with oxygen atoms of neighboring [UO2(SeO4)2 · D2O]2? layers. 相似文献