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1.
The crystal structures of three minerals (arsenosulvanite, V,As-germanite, and colusite) of the general crystal chemical formula (As, Ge, Sn, Sb, V)6S32, where CuM, VM are cations at interstitial positions, 0.2 x 2.0, 2.7 y 0, (space group , a = 10.527; 10.600; 10.653 ; R = 0.066; 0.046; 0.033) have been determined using single-crystal X-ray diffraction data. The minerals are the two structural modifications of the compound with the ideal formula V2Cu24As6S32; they differ from each other in the occupancy of the interstitial position 2a. In colusite, this position is occupied by the V5+ cations; in arsenosulvanite and V,As-germanite, by Cu2+. A characteristic feature of the structures is the presence of octahedral [ S4]Cu6 ( = V, Cu) complexes not directly interacting with each other and lying inside the Laves polyhedra. In the structures of arsenosulvanite and V,As-germanite, a sulvanite framework consisting of interpenetrating Laves polyhedra T3S4 ( = V, Cu; T = Cu, As, Ge) has been found. The sulvanite framework is statistically distributed over the sphalerite matrix. The variable composition of the minerals is due to heterovalent isomorphism in the sphalerite position 6c. Charge disbalance arising from substitution of the pentavalent arsenic cations by cations of lower valence is compensated by the appearance of additional Cu2+ cations. The nonstoichiometry of the compositions is explained by the presence of vacancies in the interstitial and sphalerite positions.  相似文献   

2.
The crystals of [Co6H2O][Co4H2O2Gly]2SO4 were studied by X-ray diffraction analysis (triclinic, P , a = 5.975(5), b = 15.469(5), c = 6.765(5) , =120.71(5), =83.23(5), =98.77(5)°). The structure contains complex cations of two types: [Co6H2O]2+ and [Co4H2O2Gly]2+ and SO 4 2– anions linked by hydrogen bonds and electrostatic forces. Three chemically nonequivalent charged layers can be distinguished in the structure: one layer is formed by cobalt hexaaqua complexes, another by [Co4H2O2Gly]2– complexes, and the third layer consists of sulfate anions interlaying the former two. The layers alternate along the b axis and are connected by a 3D system of hydrogen bonds.  相似文献   

3.
The chemical bonding between two closed-shell molecular fragments has been analyzed in terms of comparison of the antisymmetrized product of wave functions of the fragments with the wave function of a molecule composed of these fragments M . As a measure of the fragments' electronic structure variation upon molecule formation we took the cosine of the angles between M and in Hilbert space, as well as between the corresponding first-order density matrices M and . As an example, compounds of the type BH3L (L=CO, NH3, PH3, H2O, PF3) have been considered. It is stressed that a necessary condition of chemical bonding between closed-shell fragments is the contribution of vacant orbitals of fragments into the bond.Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Struktumoi Khimii, Vol. 34, No. 3, pp. 3–8, May–June, 1993.Translated by L. Smolina  相似文献   

4.
An x-ray diffraction structural investigation was carried out on amphi-phenylglyoxime (PGO) and amphi-chloroglyoxime (CGO), which crystallizes as a monohydrate, on a diffractometer using MoK radiation. The structure of PGO was solved by the direct method using 745 reflections, R=0.029. The structure of CGO was solved using the direct method using 1397 reflections, R=0.031. The unit cell parameters of the triclinic crystals of PGO, C8H8N2O2, at 23°C are as follows: a=3.966(1), b=8.624(2), c=11.792(2) Å, =91.04(3), =97.17(3), =95.52(2)°, Z=2, space group P . The unit cell parameters of the triclinic cells of CGO, C2H3N2O2Cl·H2O, at 23°C are as follows: a=3.719(1), b=12.479(7), c=13.47(1) Å, =70.76(7), =82.09(8), =89.93(5)°, Z=4, space group P . The PGO and CGO molecules have amphi configuration of the dioxime fragments, in which the oxime group -systems are conjugated. The molecules in both structures are associated by hydrogen bonds and form infinite chains in the PGO structure and infinite layers in the CGO layers.Institute of Heteroorganic Compounds, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 30, No. 6, pp. 112–116, November–December, 1989.  相似文献   

5.
Layers of [(CH3)3SiO]8(SiO1.5)8 and [(CH3)3SiO]12(SiO)6 organosilicon compounds obtained by chemical vapor deposition were investigated by X-ray diffraction (DRON-RM4, R = 192 mm, CuK radiation) and Raman spectroscopy (Triplemate, SPEX). The layers were found to be ideally oriented polycrystalline films. The octakis-(trimethylsiloxy)octasilsesquioxane polycrystals are oriented in one crystallographic direction — [001], while the dodecakis-(trimethylsiloxy)cyclohexa-siloxane polycrystals are oriented in the and directions. Crystal structure analysis in these directions yielded the type of the planar lattice followed by the molecules and their orientation relative to the support.Original Russian Text Copyright © 2004 by S. A. Gromilov, T. V. Basova, D. Yu. Emelyanov, A. V. Kuzmin, and S. A. ProkhorovaTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 497–501, May–June 2004.  相似文献   

6.
The mixed-ligand complexes Zn(2, -Bipy)(i-PrOCS2)2 (I) and Zn(2, -Bipy)(i-BuOCS2)2 (II) were synthesized. Their structures were solved using the X-ray diffraction data (CAD-4 diffractometer, MoK radiation, 1873 and 1948 F hkl , R = 0.0357 and 0.0338). The crystals are triclinic with unit cell dimensions a = 10.002(2), b = 11.080(2), c = 11.756(2) , = 78.46(3), = 75.49(3), = 63.50(3)°, V = 1122.9(4) 3, Z = 2, space group (for complex I) and a = 8.760(2), b = 12.520(3), c = 13.252(3) , = 63.93(3), = 71.10(3), = 88.01(3)°, V = 1225.2(5) 3, Z = 2, space group (for II). The structures are based on discrete monomeric molecules. The polyhedra of Zn atoms are tetragonal pyramids (ZnN2S3, c.n. 4+1, both bidentate and monodentate ligands coordinated to the Zn atom). The packing of molecules and the character of their interaction in the structures are considered.  相似文献   

7.
Fluoride and ammonium ion dynamics in (NH4)3Sb4F15 was studied by 1H and 19F NMR spectroscopy in the range 180-440 K. Types of ionic motion were determined, and their activation energies were estimated. The crystal structure of a single crystal of (NH4)3Sb4F15 (space group ) was solved. In the range K, a reversible phase transition has been found. Based on the experimental values of conductivity of (NH4)3Sb4F15 ( S/cm at T = 440 K), this antimony(III) fluoride is classified as a superionic conductor.  相似文献   

8.
Single crystals of the mixed-ligand complex compound [HgPhen(Et2NCS2)2] were obtained. The crystal structure of the compound was determined by X-ray diffraction analysis (CAD-4 diffractometer, Mo radiation, 3640 F hkl , R = 0.0280). Triclinic crystals with cell parameters a = 10.308(2), b = 11.171(3), c = 11.552(2) , = 94.16(2), = 96.66(1), = 105.17(2)°, V = 1267.8(5) 3, Z = 2, d calc = 1.774 g/cm3, space group . The structure is composed of discrete monomer molecules. The coordination polyhedron of the Hg atom is a distorted octahedron formed by four S atoms of the two cyclic bidentate Et2 ligands and two N atoms of the cyclic bidentate Phen ligand. The character of interactions between [MPhen(Et2NCS2)2] (M = Zn, Cd, Hg) molecules and their packing in the structure are considered.  相似文献   

9.
Measurements of NMR spin-lattice relaxation times T 1 were performed for sorbed H2O and D2O in a sulfonated ion-exchange resin at varying degrees of hydration with alkaline cations as counter ions. From the sorption isotherms at three different temperatures the partial molar enthalpies and entropies of sorption show a minimum for all alkaline cations at water concentrations of n 0.8, i.e., there are 0.8 water molecules per –SO 3 group. The first water molecules sorbed in the ion-exchange resin matrix are characterized by anisotrtopic rotational diffusion processes with correlation times of the order of 1 50 ns and 2 30 ps, respectively. This indicates that they are located in the electrostatic field between the corresponding ion pair. Although these two correlation times are very similar at a given temperature for all alkaline cations studied in the present investigation, the existence of a second spin-lattice relaxation time for sorbed H2O at n=0.8 indicates that for Cs about 50% of the sorbed water diffuses between locations in the resin. This fraction decreases with ionic radii and with falling temperatures. For Li the amount is less than 20%.  相似文献   

10.
Single crystals of the mixed-ligand complex compounds of Cd(i-Bu2PS2)2 with Phen and 2,2-Bipy have been obtained. The crystal structures of the complexes [CdPhen{(i-C4H9)2PS2}2] (I) and [Cd(2,2-Bipy){(i-C4H9)2PS2}2] (II) were determined by X-ray diffraction (CAD-4 diffractometer, MoK radiation, 1739 F F hkl , R = 0.0417 for I and 2612 F hkl , R = 0.0442 for II). Monoclinic crystals with unit cell parameters a = 15.640(3), b = 20.797(4), c = 11.559(2) , = 111.21(3)°, V = 3505(1) 3, Z = 4, d calc = 1.348 g/cm3, space group (I); a = 14.737(3), b = 20.918(4), c = 11.517(2) , = 105.53(3)°, V = 3421(1) 3, Z = 4, d calc = 1.334 g/cm3, space group (II). The structures consist of discrete monomer molecules. The coordination polyhedra of the Cd atoms are distorted octahedra formed by four S atoms of two cyclic bidentate ligands i-Bu2 and two N atoms of the cyclic bidentate ligands — Phen or 2, -Bipy molecules. The interaction between molecules I and II in the structures and the packing modes are considered.  相似文献   

11.
Within the prospect of quantifying the geometrical dissimilarity of molecular models on the basis of a thermodynamical formalism, the algebra of stereogenic pairing equilibria is reviewed and applied to molecular geometry: developing Rassat's proposition, an interaction energy of two figures F and F is taken as proportional tod H Emphasis>/2 (F, F), whered H denotes the Hausdorff distance. IfG is a group of rotations in E n the geometrical version of the general equation (E) of the chemical algebra defines a distance extensionD p(F,F) ofd H(F,F), which is independent of the orientations of F and F, and where the coefficientp is interpreted as the reciprocal of a temperature-like parameter:p 1/T. At K (p = ), no formal entropy contributes to the definition of the uniform distanceD . At K (p = 0), the discrimination between homo- and hetero-pairing of figures by the harmonic distance Do is averaged over orientation states. Temperature-dependent chirality measuresc p are derived fromD p, andc is analogous to Mislow's chirality measure. If T and oT are normalized enantiomorphic triangles with coincident centroids inE 2,c p(T) =D p (T, T) is calculated forp = 0 andp = , and discussed for 0 <p < . Finally, the Hausdorff interaction model is putatively related to energy profiles versus dihedral angle inmeso- anddl-molecules.  相似文献   

12.
The local structure of Co2+ at the -, , and -cation sites of zeolite ZSM-5 was calculated in terms of density functional theory using the cluster approach. The local geometry of the oxygen environment of Co2+ is characterized; it is found that the ion stabilization energy increases in the series .  相似文献   

13.
The interaction of the cobalt phosphine complexes Co(N2)(PPh3)3, HCo(N2)(PPh3)3 and H3Co(PPh3)3 with styrene yields mono and dinuclear complexes identified by the ESR method. A paramagnetic complex, Co(PPh3) (styrene)2, is one of the intermediates in the catalytic hydrogenation of styrene.
Co(N2)(PPh3)3, HCo(N2)(PPh3)3 H3Co(PPh3)3 . , Co(PPh3) ()2.
  相似文献   

14.
The crystal structure of the title compound, [Sr(C18H36N2O8)(H2O)2]2+·2SCN (I), was investigated by X-ray diffractometry: space group , a = 10.724(3), b = 15.512(3), c = 16.826(4) , = 97.96(3)°, Z = 4. The structure was solved by direct methods. The full-matrix least-squares anisotropic refinement converged to R = 0.038 for all 3837 independent measured reflections (CAD-4 automatic diffractometer, ). In the structure of I, the Sr2+ cation (c.n. 10) lies in the cavity of the cryptand ligand and is coordinated by all of its eight heteroatoms (6O+2N) and two O atoms of the two water molecules; its coordination polyhedron is a distorted two-base-centered bicapped trigonal prism. The cryptand ligand in I has an asymmetric conformation. The crystal structure of I has interionic hydrogen bonds (formed by the H atoms of the ligand water molecules) linking the complex cations and the SCN anions into complex infinite chains.  相似文献   

15.
Summary Dichloro complexes of PdII, [Pd(L–L)Cl2], where L–L=1-(thiomethyl)-2-(diphenylarsino)ethane (S–As) or 1-(thiomethyl)-2-(diphenylphosphino)ethane (S–P) andtrans-[PdL2Cl2], where L=diphenyl(2-phenylethyl)-phosphine (PE), diphenyl(1-naphthyl)phosphine (PN) orN-methyl-2-thiophenealdimine (SN), have been prepared and characterized. The reactions of these complexes with MeLi were investigated. The dimethyl complexes [Pd(L–L)Me2] (L–L=S–As, S–P) and [Pd(PE)Me2] were isolated and characterized. Reaction of [Pd(L–L)Me2] (L–L=S–As, S–P) with HCl affords the monomethyl derivatives [Pd(L–L)Me(Cl)]. In contrast to the Pt analogues, [Pd(L–L)Me2] and [Pd(L–L)Me(Cl)] are relatively less stable than [Pt(L–L)Me2] and [Pt(L–L)Me(Cl)].  相似文献   

16.
Zusammenfassung Es wurde eine Reihe von Komplexen des zweiwertigen Nickels mit den Schiffbasen H2L,H2L der Zusammensetzung NiL·ROH(R=Me, Et, Pr, i-Pr)und NiL ·ROH (R=Me, Et, Pr, i-Pr, Bu) hergestellt und deren thermischer Zerfall untersucht. Es wurde festgestellt, dass bei den Addukten NiL·ROH der Zerfall unter Abspaltung des Alkohols (Zwischenprodukt NiL) verläuft, während bei NiL·ROH sofort nach der Abspaltung des Alkohols zur Massenzunahme auf TG-Kurve durch Oxidation des Stoffes kommt. Das Plateau, das dem Zwischenprodukt NiL entspricht, ist hier nur in der Ineratmosphäre erhaltbar. Es wurden auch die Aktivierungsenergien für die Abspaltung des Alkohols berechnet.
Ni(II) Schiff base complexes of compositions NiL ROH (R=Me, Et, Pr, i-Pr) and NiL·ROH (R=Me, Et, Pr, i-Pr, Bu) were prepared and investigated by methods of thermal analysis. The thermal decomposition of NiL·ROH led to NiL (plateau in TG curve), whereas NiL·ROH underwent a similar decomposition only in an inert atmosphere (N2); thermal decomposition in air involved alcohol fragmentation, followed by a mass increase due to oxidation by atmospheric oxygen. The activation energy of alcohol fragmentation was calculated.

NiL · ROH (R=-, -, - ) NiL-ROH (R=-, -, -, -, ). , NiL ] NiL — . , . .


Wir möchten uns sehr herzlich bei Doz. RNDr. E. Jóna, CSc. und RNDr. I. Horváth, CSc. für die Messungen in der Stickstoffatmosphäre in SAV Bratislava bedanken.  相似文献   

17.
Fine yellowish orange crystals of the binuclear complex K2[RuNO(NO2)3(-OH)]2 were obtained by the reaction of K2[RuNO(NO2)4OH] with a stoichiometric amount of 0.8 M nitric acid at room temperature. The compound was investigated by IR spectroscopy, X-ray phase analysis (DRON-3M, CuK radiation), and X-ray diffraction analysis (Nonius CAD-4, MoK radiation, graphite monochromator, scan mode, 1406 reflections). The crystals are poorly soluble in water and practically insoluble in ethanol and acetone; the compound is stable when stored in air. Crystal data for H2K2N8O16Ru2 are: a = 8.596(2), b = 10.111(1), c = 9.537(1) , = 104.42(1)°, V = 802.8(2) 3, space group , Z = 2, calc = 2.691 g/cm3. The structure is built of [RuNO(NO2)3(- complex anions and K+ cations.  相似文献   

18.
For nonaqueous electrolytes, using the HSAB principle, we tried to correlate the conductivity maxima MAX, vs. only two intrinsic parameters: chemical hardness of the solvent and that of the salt. Thus, not only the nature of the solvent but also that of the salt were taken into account. We were able to predict for a given solvent the variation of MAX as a function of the hardness of the salt and that of the solvent: MAX = K(1 – ||/SOLVENT) with || = |SOLVENTSALT| and K a constant in S-cm–1 independent of the salt, but not of the solvent.  相似文献   

19.
The title compound, [cis-Co(en)2(NO2)2](NO2) (1), crystallizes in the polar, nonenantiomorphic, monoclinic space group, Cc, with lattice constants:a=9.198(2) Å,b=12.444(2),c=9.963(3), and=96.76(2)°;V=1132.39 Å3 andd(calc;Z=4) =1.860 g cm–3. Thus, with NO2– as the counteranion, [cis-Co(en)2(NO2)2] crystallizes in a heterochiral lattice containing racemic pairs of cations. A total of 2699 data were collected over the range of 4°270°; of these, 1859 (independent and withI3(I)) were used in the structural analysis. Data were corrected for absorption (=15.465 cm–1) and the relative transmission coefficients ranged from 0.9934 to 0.7112. Refinement was carried out for both lattice polarities and the finalR(F) andR w (F) residuals were, respectively, 0.0242 and 0.0202 for (–––) and 0.0264 and 0.0243 for (+++). Thus, the former was selected as correct for our specimen.Unlike all previous X-ray diffraction studies of the structural properties of the cation [cis-Co(en)2(NO2)2]+, which are found to have a pair of oppositely configured en rings [i.e., () or ()], we find that in1 the cations are in the lowest energy conformation and configuration; i.e., () or (). We attribute this change in configuration to the formation of strong interionic hydrogen bonds between nitrite anion oxygens and the axial—NH2 hydrogens, which markedly weaken the intermolecular and intramolecular hydrogen bonds between ligand—NO2 oxygens and the hydrogens of those same amine moieties. Thus, the nitrite anions behave exactly as nitrate anions, except that the hydrogen bonds found here are stronger than those formed by the latter. This is as expected since the negative charge is delocalized over two, instead of three, oxygens.  相似文献   

20.
Summary The problem of finding eigenvalues and eigenstates of the generalized perturbed eigenvalue equation = g3(+) is considered. The eigenvalues and the eigenstates of the unperturbed eigenvalue equation = are assumed to be known. Matrices , and can be arbitrary, except for the requirement that be nonsingular and that the eigenstates of the unperturbed equation be complete. It is shown that the eigenvalues and the eigenstates of the perturbed equation can be easily obtained if the rank of the generalized perturbation , is small. A special case of low rank perturbations are piecewise local perturbations which are common in physics and chemistry. If the perturbation is piecewise local with fixed localizability, the operation count for the derivation of a single eigenvalue and/or a single eigenstate is (n). If the perturbation has a fixed rank, the operation count for the derivation of all eigenvalues and/or all eigenstates is (n 2).Research supported by the Welch Foundation of Houston, Texas, and by the Yugoslav Ministry for Development (Grant P-96)  相似文献   

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