Secondary interactions in decachloro-closo-decaborates of alkali metals M2[B10Cl10] (M = K+ and Cs+): 35Cl NQR and X-ray studies

Polyhedron ◽  
2016 ◽  
Vol 117 ◽  
pp. 561-568 ◽  
Author(s):  
E.A. Kravchenko ◽  
A.A. Gippius ◽  
A.V. Vologzhanina ◽  
V.V. Avdeeva ◽  
E.A. Malinina ◽  
...  
Keyword(s):  
Alkali Metals ◽  
X Ray ◽  
Secondary Interactions ◽  
35Cl Nqr

Secondary interactions in decachloro-closo-decaborates R2[B10Cl10] (R = Et3NH+, Ph4P+, and [Ag(NH3)2]+): 35Cl NQR, PW-DFT, and X-ray studies

2016 ◽  
Vol 447 ◽  
pp. 22-31 ◽  
Author(s):  
E.A. Kravchenko ◽  
A.A. Gippius ◽  
A.A. Korlyukov ◽  
A.V. Vologzhanina ◽  
V.V. Avdeeva ◽  
...  
Keyword(s):  
X Ray ◽  
Secondary Interactions ◽  
35Cl Nqr

scholarly journals Selective Crystallization of Four Bis(phthalocyaninato)neodymium(III) Polymorphs

2020 ◽  
Author(s):  
Maegan Dailey ◽  
Claire Besson
Keyword(s):  
Crystal Packing ◽  
Detailed Comparison ◽  
Protonated Form ◽  
Slow Evaporation ◽  
X Ray Diffraction ◽  
Acid Base ◽  
Initial Oxidation ◽  
X Ray ◽  
Secondary Interactions ◽  
Selective Crystallization

Four polymorphs of bis(phthalocyaninato)neodymium(III) were reproducibly and selectively crystallized by the slow evaporation of saturated solutions. The obtained phase depended on the initial oxidation state of the NdPc<sub>2</sub> molecule and the choice of solvent. Single-crystal X-ray diffraction studies were used to correct previous mis-identifications and provide missing coordinates for the γ-phase as well as a detailed comparison of molecular structure and crystal packing in all NdPc<sub>2</sub> polymorphs. The primary feature in all phases is columnar stacking based on parallel π π interactions, with a variety of slip angles within those stacks as well as secondary interactions between them. Chemical redox and acid-base titrations, performed on re-dissolved crystals demonstrate that NdPc<sub>2</sub><sup>+</sup> and NdPc<sub>2</sub><sup>-</sup> are easily obtained through weak oxidizing and reducing agents, respectively. Additionally, we show that the protonated form of the NdPc<sub>2</sub><sup>-</sup> complex has a nearly identical UV-Vis spectra to that of neutral NdPc<sub>2</sub>, explaining some of the confusion over chemical composition in previously published literature.<br>

Die neuen Oxoarsenate(III) AAsO2 (A = Na, K, Rb) und Cs3As5O9. Darstellung, Kristallstrukturen und Raman-Spektren / The New Oxoarsenates(III) AAsO2 (A = Na, K, Rb) and Cs3As5O9. Synthesis, Crystal Structures and Raman Spectra

2003 ◽  
Vol 58 (7) ◽  
pp. 620-626 ◽  
Author(s):  
Franziska Emmerling ◽  
Caroline Röhr
Keyword(s):  
Crystal Structures ◽  
Metal Content ◽  
Alkali Metals ◽  
Alkaline Metal ◽  
Tetrahedral Coordination ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Metal Arsenates

The new alkaline metal arsenates(III) were synthesized at a temperature of 500 °C via reaction of stoichiometric mixtures of the elemental alkali metals A and As2O3. In the crystal structures of the four title compounds, which have been determined by single crystal x-ray diffraction, the As(III) atoms are in ψ-tetrahedral coordination by oxygen exclusively. In NaAsO2 (orthorhombic, space group Pbcm, a = 1429.6(9), b = 677.3(3), c = 509.1(2) pm, Z = 8) and the compounds AAsO2 (A = K/Rb, orthorhombic, space group Pbcm, a = 715.1(2)/729.7(5), b =748.0(1)/775.2(5), c = 539.20(17)/541.1(3) pm, Z = 4) the AsO3 ψ-tetrahedra are condensed to form zig-zag chains [AsOO2/2]−. In the Cs phase Cs3As5O9 with a lower alkaline metal content (trigonal, space group P31m, a = 845.5(3), c = 602.6(2) pm, Z = 1) the two crystallographically independent ψ-tetrahedra AsO3/2 and AsOO2/2 are connected in a 2:3 ratio to give polar sheets [As5O9]3−.

Die neuen Oxobismutate(III) Cs6Bi4O9, K9Bi5O13 und A2Bi4O7 (A = Rb, Cs) / The New Oxobismutates(III) Cs6Bi4O9, K9Bi5O13 and A2Bi4O7 (A = Rb, Cs)

2002 ◽  
Vol 57 (10) ◽  
pp. 1090-1100
Author(s):  
Franziska Emmerling ◽  
Caroline Röhr
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Alkali Metals ◽  
Mixed Valence ◽  
Three Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Mixed Valence Compound

AbstractThe title compounds were synthesized at a temperature of 700 °C via oxidation of elemental Bi with the hyperoxides AO2 or via reaction of the elemental alkali metals A with Bi2O3. Their crystal structures have been determined by single crystal x-ray diffraction. They are dominated by two possible surroundings of Bi by O, the ψ-trigonal-bipyramidal three (B) and the ψ-tetrahedral four (T) coordination. Cs6Bi4O9 (triclinic, spacegroup P1̄, a = 813.82(12), b = 991.60(14), c = 1213.83(18) pm, α = 103.658(2), β = 93.694(3), γ = 91.662(3)°, Z = 2) contains centrosymmetric chain segmentes [Bi8O18]12- with six three- (T) and two four-coordinated (B) Bi(III) centers. K9Bi5O13 (monoclinic, spacegroup P21/c, a = 1510.98(14), b = 567.59(5), c = 2685.6(2) pm, β = 111.190(2)°, Z = 4) is a mixed valence compound with isolated [BivO4]3- tetrahedra and chains [BiIII4O9]6- of two T and two B coordinated Bi. In the compounds A2Bi4O7 (A = Rb/Cs: monoclinic, C2/c, a = 2037.0(3) / 2130.6(12), b = 1285.5(2) / 1301.9(7), c = 1566.6(2) / 1605.6(9) pm, β = 94.783(3) / 95.725(9)°, Z = 8) ribbons [Bi4O6O2/2]2- are formed, which are condensed to form a three-dimensional framework.

On the Phase Transition of Bis(pyridinium)hexachlorometallates, (C5H5NH)2[MCl6], M = Sn, Te, Pb, Pt. An X-Ray and 35Cl NQR Study

1987 ◽  
Vol 42 (7) ◽  
pp. 739-748 ◽  
Author(s):  
Dirk Borchers ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Phase Ii ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray ◽  
Lattice Constants ◽  
Pyridinium Ring ◽  
35Cl Nqr ◽  
Low Temperature Phase

A phase transition has been observed in bis(pyridinium) hexachlorometallates (C5H5NH)2[MIVCl6]. M = Sn. Te. Pb. Pt. The crystal structure of the low temperature phase II of the salt with M = Sn was determined, space group C 1ḷ- P 1̅, Z = 1 (a = 734.1pm, b = 799.0 pm, c = 799.7 pm,α= 83.229°. β = 65.377°, γ= 84.387°, T = 297 K). The four compounds are isotypic in phase II as well as in the high temperature phase I (C2H2-B2 /m, Z = 2) for which the crystal structure is known for M = Te . The lattice constants of all compounds (both phases) are given. The temperature dependence of the 35Cl NQR spectrum was investigated. The three line 35Cl NQR spectrum is in agreement with the crystal structure. The dynamics of the pyridinium ring shows up in a fade out of part of the 35Cl NQR spectrum . The influence o f H ↔ D exchange on 35Cl NQR is studied and an assignment of ν (35Cl) ↔ Cl(i) is proposed. The nature of the phase transition P1̅ (Z = 1) ↔ B2 /m (Z = 2) is discussed.

scholarly journals Synthesis and X-Ray Crystal Structure of 1,1'-Bis(diphenyphosphino)ferrocene Supported CuSCF3 Complex

2019 ◽  
Vol 31 (8) ◽  
pp. 1877-1880
Author(s):  
Yi Yang ◽  
Gen Luo ◽  
Xia Tong ◽  
Yu-Mei Shu ◽  
Yu-Bing Zheng
Keyword(s):  
31P Nmr ◽  
Monoclinic Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
R Factor ◽  
Secondary Interactions ◽  
Short Contacts ◽  
Strong Dipole ◽  
Cuprous Complex ◽  
Aromatic Hydrogen

We report herein the synthesis of CuSCF3 complex supported by 1,1'-bis(diphenyphosphino)ferrocene via deoxygenative reduction of Langlois reagent (CF3SO2Na). This cuprous complex [(dppf)Cu(SCF3)] was fully characterized by elemental analysis and 1H (13C, 19F, 31P) NMR spectra. In addition, the molecular structure of [(dppf)Cu(SCF3)] was established by X-ray crystallography. The crystal of compound 1 crystallizes in monoclinic, space group P21/n with a = 11.4366(9), b = 19.1340(16), c = 14.0625(11) Å, V = 3072.62(2) Å3, Z = 4, Z’ = 0, C35H28CuF3FeP2S, Mr = 719.00 and R-factor = 3.69. The short contacts between the two fluorine atoms of CF3S moiety and aromatic hydrogen of Cp/(Ph) rings were observed with leaving the sterically-congested fluorine untouched which highly resembled to the sibling [(PPh3)2CuSCF3]. These interesting secondary interactions in the crystal lattice were explained by the electrostatic forces in terms of the strong dipole of C-F bonds.

scholarly journals Mineralogical characteristics and sources of alkali metals in the No. 6 coal seam from the Fukang mining area of the Zhunnan coalfield, Xinjiang province, Northwest China

2019 ◽  
Vol 37 (3) ◽  
pp. 1162-1181 ◽  
Author(s):  
Yun Xu ◽  
Handong Liang ◽  
Ning Zhang
Keyword(s):  
Coal Seam ◽  
Inductively Coupled Plasma ◽  
Alkali Metals ◽  
Northwest China ◽  
Mining Area ◽  
Major Elements ◽  
Middle Part ◽  
X Ray ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry

Minerals in coal are of great significance in determining coal properties, washing, combustion, gasification, and liquefaction. The content of alkali metals in coal is an important factor determining corrosion and/or erosion in combustion boilers. Eleven coal samples were taken from the No. 6 coal seam of the Fukang mining area, Zhunnan coalfield, Xinjiang province, China. X-ray fluorescence, inductively coupled plasma-mass spectrometry, low-temperature ashing-X-ray diffraction, and electron probe microanalyzer were used for analyzing the minerals, major elements, and trace elements of the coal. The results indicated that the minerals mainly consist of dawsonite, dolomite, albite, calcite, kaolinite, quartz. The average content of Na2O in the ash of the No. 6 coal seam samples was 10.91%. Na mainly occurs in the form of organic compounds in the No. 6 coal seam, then in the form of inorganic minerals, such as dawsonite and albite. Na in surface and underlying strata was brought into the coal by water and combined with organic matter, resulting in relatively high Na contents in the upper and bottom parts of the coal seam and relatively low Na contents in the middle part.

Synthesis and Characterization of Large Single Crystals of Silicon and Germanium Clathrate-II Compounds and a New Tin Compound with Clathrate Layers

2000 ◽  
Vol 626 ◽  
Author(s):  
Svilen Bobev ◽  
Slavi C. Sevov
Keyword(s):  
Alkali Metal ◽  
Single Crystals ◽  
Alkali Metals ◽  
Measured Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Mixed Alkali ◽  
Pauli Paramagnetism ◽  
Silicon And Germanium

ABSTRACTWe have synthesized large single crystals of clathrate-II compounds with frameworks of silicon and germanium by employing mixed alkali metal countercations. The combinations of alkali metals are rationally selected in order to fit the different cages of the clathrate-II structure. This approach leads to the following stoichiometric and fully “stuffed” compounds: Cs8Na16Si136, Cs8Na16Ge136, Rb8Na16Si136 and Rb8Na16Ge136. The structures and the corresponding Si-Si and Ge-Ge distances are elucidated and established with high accuracy from extensive single crystal X-ray diffraction work. The compounds are stoichiometric, metallic, and are very stable at a variety of extreme conditions such as heat, concentrated acids, hydrothermal treatment etc. No evidence was found for vacancies in the silicon and germanium networks or partial occupancies of the alkali metal sites. The stoichiometry of these fully “stuffed” clathrates is consistent with the measured temperature independent Pauli paramagnetism, supported also by the conductivity measurements on single crystals and thermopower measurements on pellets. A new compound with novel clathrate-like structure forms when small and large cations are combined with tin. The new materials, A6Na18Sn46 (A = K, Rb, Cs), are made of clathrate layers and the interlayer space filled with Sn4-tetrahedra and alkali-metal cations. Its formula can be rationalized as A6Na6Sn34 + 3·Na4Sn4 (one clathrate layer and three tin tetrahedra). The compound is stable in air and is being currently tested at other conditions. Detailed measurements of its transport properties are under way.

Multinuclear NMR and Powder X-ray Diffraction Studies of Si and Sn Clathrates of Alkali Metals: Vacancies, Disorder and Knight Shifts

2001 ◽  
Vol 691 ◽  
Author(s):  
Michael J. Ferguson ◽  
Igor L. Moudrakovski ◽  
Christopher I. Ratcliffe ◽  
John S. Tse
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
Nmr Spectra ◽  
Alkali Metals ◽  
Rietveld Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Multinuclear Nmr ◽  
Binary Metal ◽  
Knight Shifts

ABSTRACTThe Structure I type binary metal clathrates of K/Si, Rb/Si and Cs/Sn have been synthesised and studied by powder X-ray diffraction and solid state NMR. Rietveld analysis shows that in all three materials some of the cages are empty, and that in the Cs/Sn clathrate there are vacancies in the Sn framework. The NMR results yield Knight shifts for 29Si and 39K and confirm that the Cs/Sn clathrate is not conducting. Many of the features of the NMR spectra can be understood in terms of the distributions of atom vacancies.

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