scholarly journals Single Crystal X-ray Structure Analyses of Thallides: Halide Incorporation and Mixed Alkali Sites in A8Tl11X (A = K, Rb, Cs; X = Cl, Br)

Proceedings ◽  
2018 ◽  
Vol 2 (14) ◽  
pp. 1124
Author(s):  
Stefanie Gärtner ◽  
Susanne Tiefenthaler
Keyword(s):  
Single Crystal ◽  
Alkali Metals ◽  
Data Sets ◽  
Moisture Sensitivity ◽  
Metal Compounds ◽  
X Ray ◽  
Mixed Alkali ◽  
Extra Electron ◽  
Alkali Metal Compounds ◽  
New Compounds

A8Tl11 (A = alkali metal) compounds have been known since the investigations of Corbett et al. in 1995 and still are matter of current discussions as the compound includes one extra electron referred to the charge of the Tl117− cluster. Attempts to substitute the charge by incorporation of a halide atom succeeded for the lightest homologue of the group, Cs8Ga11Cl, and powder diffraction experiments for the heavier homologues also suggested the formation of analogous compounds. However, X-ray single crystal studies on A8Tl11X to prove this substitution and to provide a deeper insight into the influence on the thallide substructure have not yet been performed, probably due to severe absorption combined with air and moisture sensitivity for this class of compounds. In our contribution we present single crystal X-ray analyses of the new compounds Cs8Tl11Cl0.8, Cs8Tl11Br0.9 and Cs5Rb3Tl11Cl0.5. It is shown that a (partial) incorporation of halide can also be indirectly determined by examination of the Tl-Tl distances for low resolved data sets, e.g., for Cs5.7K2.3Tl11Cl?. Mixed occupied sites by two different alkali metals indicate a dependence on the cesium content, the systems K/Rb–Tl–Br and K/Rb–Tl–Cl only gave rise to the formation of the higher reduced (K/Rb)8Tl11 and the less reduced by-product (K/Rb)15Tl27. We have not been able to prove the formation of halide including thallides in the absence of cesium.

scholarly journals Structural Chemistry of Halide including Thallides A8Tl11X1−n (A = K, Rb, Cs; X = Cl, Br; n = 0.1–0.9)

Crystals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 319 ◽  
Author(s):  
Stefanie Gärtner ◽  
Susanne Tiefenthaler ◽  
Nikolaus Korber ◽  
Sabine Stempfhuber ◽  
Birgit Hischa
Keyword(s):  
Alkali Metal ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Moisture Sensitivity ◽  
Metal Compounds ◽  
X Ray ◽  
Extra Electron ◽  
Alkali Metal Compounds ◽  
New Compounds ◽  
Insight Into

A8Tl11 (A = alkali metal) compounds have been known since the investigations of Corbett et al. in 1995 and are still a matter of current discussions as the compound includes one extra electron referred to the charge of the Tl117− cluster. Attempts to substitute this additional electron by incorporation of a halide atom succeeded in the preparation of single crystals for the lightest triel homologue of the group, Cs8Ga11Cl, and powder diffraction experiments for the heavier homologues also suggested the formation of analogous compounds. However, X-Ray single crystal studies on A8Tl11X to prove this substitution and to provide a deeper insight into the influence on the thallide substructure have not yet been performed, probably due to severe absorption combined with air and moisture sensitivity for this class of compounds. Here, we present single crystal X-Ray structure analyses of the new compounds Cs8Tl11Cl0.8, Cs8Tl11Br0.9, Cs5Rb3Tl11Cl0.5, Cs5.7K2.3Tl11Cl0.6 and K4Rb4Tl11Cl0.1. It is shown that a (partial) incorporation of halide can also be indirectly determined by examination of the Tl-Tl distances, thereby the newly introduced cdd/cdav ratio allows to evaluate the degree of distortion of Tl117− clusters.

scholarly journals Lower resolution Laue neutron data yield correct nanocluster formulations

2014 ◽  
Vol 70 (a1) ◽  
pp. C187-C187
Author(s):  
Alison Edwards
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Diffraction Pattern ◽  
Precise Determination ◽  
Data Sets ◽  
X Rays ◽  
Low Resolution ◽  
Neutron Data ◽  
X Ray ◽  
Product Formulation

"The renaissance in Laue studies - at neutron sources - provides us with access to single crystal neutron diffraction data for synthetic compounds without requiring synthesis of prohibitively large amounts of compound or improbably large crystals. Such neutron diffraction studies provide vital data where proof of the presence or absence of hydrogen in particular locations is required and which cannot validly be proved by X-ray studies. Since the commissioning of KOALA at OPAL in 2009[1] we have obtained numerous data sets which demonstrate the vital importance of measuring data even where the extent of the diffraction pattern is at relatively low resolution - especially when compared to that obtainable for the same compound with X-rays. In the Laue experiment performed with a fixed radius detector, data reduction is only feasible for crystals in the ""goldilocks"" zone – where the unit cell is relatively large for the detector, a correspondingly low resolution diffraction pattern in which adjacent spots are less affected by overlap will yield more data against which a structure can be refined than a pattern of higher resolution – one where neighbouring spots overlap rendering both unusable (in our current methodology). Analogous application of powder neutron diffraction in such determinations is also considered. Single crystal neutron diffraction studies of several important compounds (up to 5KDa see figure below)[2] in which precise determination of hydride content by neutron diffraction was pivotal to the final formulation will be presented. The neutron data sets typically possess 20% or fewer unique data at substantially "lower resolution" than the corresponding X-ray data sets. Careful refinement clearly reveals chemical detail which is typically unexplored in related X-ray diffraction studies reporting high profile chemistry despite the synthetic route being one which hydride ought to be considered/excluded in product formulation."

Bis[dicarbonyl(cyclopentadienyl)ruthenium(I)] Komplexe / Bis[dicarbonyl(cyclopentadienyl)ruthenium(I)] Complexes

2002 ◽  
Vol 57 (9) ◽  
pp. 1017-1026 ◽  
Author(s):  
Herbert Schumann ◽  
Susanne Stenz ◽  
Frank Girgsdies ◽  
Stefan H. Mühle
Keyword(s):  
Single Crystal ◽  
Nmr Spectra ◽  
X Ray ◽  
Tert Butyl ◽  
New Compounds ◽  
C Nmr

Ru3(CO)12 reacts with 1-tert-butyl-2,4-cyclopentadiene (1), 1-trimethylsilyl-2,4-cyclopentadiene (2), 1-tert-butyl-3-methyl-2,4-cyclopentadiene (3), 1,3-di(tert-butyl)-2,4-cyclopentadiene (4), 1-iso-propyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (5), 1-tert-butyl-2,3,4,5-tetramethyl- 2,4-cyclopentadiene (6), 1-phenyl-2,3,4,5-tetramethyl-2,4-cyclopentadiene (7), 2,5- diphenyl-2,4-cyclopentadiene (8), or 2,3,4,5-tetraphenyl-2,4-cyclopentadiene (9) with formation of the corresponding bis[dicarbonyl(cyclopentadienyl) ruthenium(I)] complexes [RuCp# (CO)2]2 1a to 9a. The 1H and 13C NMR spectra of the new compounds 3a and 5a to 9a as well as the single crystal X-ray structures of 1a, 4a, 5a, 7a, 8a, and 9a are reported and discussed

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.

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.

Lewis-Base Adducts of Main Group 1 Metal Compounds. V. Diaquabis(quinoline)lithium(I) Bromide Bis(quinoline)

1988 ◽  
Vol 41 (3) ◽  
pp. 409 ◽  
Author(s):  
CL Raston ◽  
BW Skelton ◽  
CR Whitaker ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Structure Determination ◽  
Title Compound ◽  
Lithium Bromide ◽  
Main Group ◽  
Lewis Base ◽  
Metal Compounds ◽  
X Ray ◽  
Group 1

The title compound, an artefact of recrystallization of lithium bromide from improperly dried quinoline, has been characterized by a single- crystal X-ray structure determination. Crystals are triclinic, Pī , a 16.608(9), b 12.27(1), c 7.962(8)Ǻ, α 101.98(8),β 91.79(7),γ 92.27(6), Z 2; R was 0.058 for 2404 'observed' reflections. The cation is the first to be structurally defined for a [Li(OH2)2 (N-base)2]+ system; Li-O are 1.92(2), 1.93(2)Ǻ and Li-N 2.12(2), 2.14(2)Ǻ.

Synchrotron radiation study of yttria-stabilized zirconia, Zr0.758Y0.242O1.879

1999 ◽  
Vol 55 (5) ◽  
pp. 726-735 ◽  
Author(s):  
N. Ishizawa ◽  
Y. Matsushima ◽  
M. Hayashi ◽  
M. Ueki
Keyword(s):  
Synchrotron Radiation ◽  
Single Crystal ◽  
Yttria Stabilized Zirconia ◽  
Data Sets ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
X Ray ◽  
Ideal Position ◽  
Fluorite Type ◽  
The Ideal

The fluorite-related cubic structure of yttria-stabilized zirconia, Zr0.75 8Y0.24 2O1.87 9, has been studied by single-crystal X-ray diffraction using synchrotron radiation and by EXAFS. Two diffraction data sets obtained at X-ray energies of 512 and 10 eV below the Y K edge revealed that in the average structure Zr atoms are displaced from the origin of the space group Fm3¯m along 〈111〉 by 0.19 Å, while Y atoms reside at the origin. Approximately 48% of the O atoms occupy the ideal position in the fluorite-type structure, while 43% of O atoms are displaced from the ideal position along 〈001〉 by 0.31 Å. The remaining 9% of O atoms are presumably sited at interstitial positions. Local structures around Zr and Y are investigated by combining the results of single-crystal X-ray diffraction and EXAFS studies.

scholarly journals Removing multiple outliers and single-crystal artefacts from X-ray diffraction computed tomography data

2015 ◽  
Vol 48 (6) ◽  
pp. 1943-1955 ◽  
Author(s):  
Antonios Vamvakeros ◽  
Simon D. M. Jacques ◽  
Marco Di Michiel ◽  
Vesna Middelkoop ◽  
Christopher K. Egan ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Single Crystal ◽  
Tomographic Reconstruction ◽  
Projection Data ◽  
Data Sets ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Tomography Data

This paper reports a simple but effective filtering approach to deal with single-crystal artefacts in X-ray diffraction computed tomography (XRD-CT). In XRD-CT, large crystallites can produce spots on top of the powder diffraction rings, which, after azimuthal integration and tomographic reconstruction, lead to line/streak artefacts in the tomograms. In the simple approach presented here, the polar transform is taken of collected two-dimensional diffraction patterns followed by directional median/mean filtering prior to integration. Reconstruction of one-dimensional diffraction projection data sets treated in such a way leads to a very significant improvement in reconstructed image quality for systems that exhibit powder spottiness arising from large crystallites. This approach is not computationally heavy which is an important consideration with big data sets such as is the case with XRD-CT. The method should have application to two-dimensional X-ray diffraction data in general where such spottiness arises.

AlkalineEarthMetal-Hydride-Iodide Compounds: Syntheses andCrystal Structures of Sr2H3I and Ba5H2I3.9(2)O2

2011 ◽  
Vol 66 (1) ◽  
pp. 21-26
Author(s):  
Olaf Reckeweg ◽  
Francis J. DiSalvo
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Structural Model ◽  
Structure Type ◽  
Lattice Parameters ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray ◽  
New Compounds

Single crystals of Sr2H3I andBa5H2I3.9(2)O2 were obtained by reacting Sr or Ba, respectively, with dried and sublimed NH4I in a 4 : 1 molar ratio in silica-jacketed Nb ampoules for 13 h at 1200 K. The crystal structures of the new compounds have been determined by means of single-crystal X-ray diffraction. Sr2H3I crystallizes in a stuffed anti-CdI2 structure isotypic to Ba2H3Cl in the space group P3m1 (no. 164) with the lattice parameters a = 426.0(1) and c = 774.9(2) pm, while Ba5H2I3.9(2)O2 crystallizes in a new structure type in the space group Cmcm (no. 63) with the lattice parameters a = 1721.0(2), b = 1452.5(2) and c = 639.03(9) pm. The structural results for Sr2H3I are corroborated by EUTAX calculations. For the disordered compound Ba5H2I3.9(2)O2, EUTAX calculations on an approximated, ordered structural model were used to find possible insights into the disorder

X-ray diffraction single-crystal structure characterization of iron ludwigite from room temperature to 15 K

2006 ◽  
Vol 39 (1) ◽  
pp. 42-45 ◽  
Author(s):  
M. Mir ◽  
Jan Janczak ◽  
Y. P. Mascarenhas
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Structural Characteristics ◽  
Density Wave ◽  
Charge Ordering ◽  
Structure Characterization ◽  
Dimensional Structure ◽  
X Ray ◽  
Extra Electron ◽  
A Charge

Iron ludwigite exhibits a superstructure between 283 and 144 K. Anomalies in its transport properties are due to a structural transition related to a charge-ordering phenomenon in the low-dimensional structure. This ordering produces a commensurate transversal charge density wave in the system. To understand these structural characteristics, an X-ray single-crystal diffraction study has been performed at 300 and 15 K. No changes were found in the crystalline structure, except for contraction of the cell volume. The bond-valence sum for each cation shows that at room temperature each Fe4—Fe2—Fe4 triad is composed of three Fe3+ions with one extra electron per triad, and at 15 K in each Fe4a—Fe2—Fe4btriad the extra electron is accommodated in the Fe4a—Fe2 pair of each triad.

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