scholarly journals Crystal Structures of Thermoelectric n- and p-Type Ba8Ga16Ge30 Studied by Single Crystal, Multitemperature, Neutron Diffraction, Conventional X-Ray Diffraction and Resonant Synchrotron X-Ray Diffraction.

ChemInform ◽  
2007 ◽  
Vol 38 (12) ◽  
Author(s):  
Mogens Christensen ◽  
Nina Lock ◽  
Jacob Overgaard ◽  
Bo B. Iversen
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
P Type

Crystal structures of (S)- and (R,S)-2,2′-bipyridine-3,3′-dicarboxylic acid 1,1′-dioxides and of their barium salts: absolute configuration and molecular distortion enforced by supramolecular self-assembly

1997 ◽  
Vol 212 (3) ◽  
Author(s):  
P. Vojtíšek ◽  
I. Císařová ◽  
J. Podlaha ◽  
Z. Žák ◽  
S. Böhm ◽  
...  
Keyword(s):  
Single Crystal ◽  
Dicarboxylic Acid ◽  
Crystal Structures ◽  
Absolute Configuration ◽  
Self Assembly ◽  
Barium Salt ◽  
X Ray Diffraction ◽  
X Ray

AbstractCrystal structures of the title compounds were determined by single crystal X-ray diffraction. Absolute configuration of the barium salt of (+)-(

Die Kristallstrukturen der isotypen Verbindungen Ba3[MoN4] und Ba3[WN4] / The Crystal Structures of the Isotypic Compounds Ba3[MoN4] and Ba3[WN4]

1991 ◽  
Vol 46 (5) ◽  
pp. 566-572 ◽  
Author(s):  
Axel Gudat ◽  
Peter Höhn ◽  
Rüdiger Kniep ◽  
Albrecht Rabenau
Keyword(s):  
Transition Metals ◽  
Single Crystal ◽  
Crystal Structures ◽  
Structure Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ternary Compounds ◽  
The Third

The isotypic ternary compounds Ba3[MoN4] and Ba3[WN4] were prepared by reaction of the transition metals with barium (Ba3N2, resp.) under nitrogen. The crystal structures were determined by single crystal X-ray diffraction: Ba3[MoN4] (Ba3[WN4]): Pbca; Z = 8; a = 1083.9(3) pm (1091.8(3) pm), b = 1030.3(3) pm (1037.5(3) pm), c = 1202.9(3) pm (1209.2(4) pm). The structures contain isolated tetrahedral anions [MN4]6- (M = Mo, W) which are arranged in form of slightly distorted hexagonal layers and which are stacked along [010] with the sequence (···AB···). Two of the three Ba atoms are situated between, the third one is placed within the layers of [MN4]-groups. In this way the structures can be derived from the Na3As structure type.

Lewis-Base Adducts of Group 1B Metal(I) Compounds. XXI The Crystal and Molecular Structures of the Unsolvated Forms of Dibromotris(triphenylphosphine)dicopper(I) and 'step' Tetrabromotetrakis(triphenyl-phosphine)tetracopper(I)

1985 ◽  
Vol 38 (8) ◽  
pp. 1243 ◽  
Author(s):  
JC Dyason ◽  
LM Engelhardt ◽  
C Pakawatchai ◽  
PC Healy ◽  
AH White
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Molecular Structures ◽  
Lewis Base ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Triphenyl Phosphine ◽  
X Ray ◽  
Crystal And Molecular Structures

The crystal structures of the title compounds have been determined by single-crystal X-ray diffraction methods at 295 K. Crystal data for (PPh3)2CuBr2Cu(PPh3) (1) show that the crystals are iso-morphous with the previously studied chloro analogue, being monoclinic, P21/c, a 19.390(8), b 9.912(5), c 26.979(9) Ǻ, β 112,33(3)°; R 0.043 for No 3444. Cu( trigonal )- P;Br respectively are 2.191(3); 2.409(2), 2.364(2) Ǻ. Cu(tetrahedral)- P;Br respectively are 2.241(3), 2.249(3); 2.550(2), 2.571(2) Ǻ. Crystals of 'step' [PPh3CuBr]4 (2) are isomorphous with the solvated bromo and unsolvated iodo analogues, being monoclinic, C2/c, a 25.687(10), b 16.084(7), c 17.815(9) Ǻ, β 110.92(3)°; R 0.072 for No 3055. Cu( trigonal )- P;Br respectively are 2.206(5); 2.371(3), 2.427(2) Ǻ. Cu(tetrahedral)- P;Br are 2.207(4); 2.446(2), 2.676(3), 2.515(3) Ǻ.

scholarly journals Accurate H-atom parameters for the two polymorphs of L-histidine at 5, 105 and 295 K

2021 ◽  
Vol 77 (5) ◽  
pp. 785-800
Author(s):  
Giulia Novelli ◽  
Charles J. McMonagle ◽  
Florian Kleemiss ◽  
Michael Probert ◽  
Horst Puschmann ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Single Crystal ◽  
Diffraction Data ◽  
Crystal Packing ◽  
Basis Sets ◽  
X Ray Diffraction ◽  
X Ray ◽  
Refinement Method ◽  
Primary Amino ◽  
Precision And Accuracy

The crystal structure of the monoclinic polymorph of the primary amino acid L-histidine has been determined for the first time by single-crystal neutron diffraction, while that of the orthorhombic polymorph has been reinvestigated with an untwinned crystal, improving the experimental precision and accuracy. For each polymorph, neutron diffraction data were collected at 5, 105 and 295 K. Single-crystal X-ray diffraction experiments were also performed at the same temperatures. The two polymorphs, whose crystal packing is interpreted by intermolecular interaction energies calculated using the Pixel method, show differences in the energy and geometry of the hydrogen bond formed along the c direction. Taking advantage of the X-ray diffraction data collected at 5 K, the precision and accuracy of the new Hirshfeld atom refinement method implemented in NoSpherA2 were probed choosing various settings of the functionals and basis sets, together with the use of explicit clusters of molecules and enhanced rigid-body restraints for H atoms. Equivalent atomic coordinates and anisotropic displacement parameters were compared and found to agree well with those obtained from the corresponding neutron structural models.

scholarly journals Crystal structures of two novel iron isocyanides from the reaction of 2,6-dimethylphenyl isocyanide, CNXyl, with bis(anthracene)ferrate(−1)

2022 ◽  
Vol 78 (1) ◽  
Author(s):  
William W. Brennessel ◽  
John E. Ellis
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Structures ◽  
Tridentate Ligand ◽  
Reductive Cyclization ◽  
X Ray Diffraction ◽  
X Ray

The reaction of the [K(18-crown-6)(thf)2]1+ (thf is tetrahydrofuran) salt of bis(anthracene)ferrate(−1), or [Fe(C14H10)2]−, with 2,6-dimethylphenyl isocyanide (CNXyl) in thf resulted in the formation of two new iron isocyanide complexes, namely, [(1,2,3,4-η)-anthracene]tris(2,6-dimethylphenyl isocyanide)iron, [Fe(C14H10)(C9H9N)3] or [Fe(1,2,3,4-η-C14H10)(CNXyl)3], and {5,6-bis(2,6-dimethylanilino)-3-(2,6-dimethylphenyl)-1,2,7-tris[(2,6-dimethylphenyl)imino]-3-azoniahept-3-ene-1,4,7-triido}tris(2,6-dimethylphenyl isocyanide)iron tetrahydrofuran disolvate, [Fe(C54H56N6)(C9H9N)3]·2C4H8O or [Fe(C54H56N6)(CNXyl)3]·2C4H8O, which were characterized by single-crystal X-ray diffraction. The former is likely an intermediate along the path to the known homoleptic [Fe(CNXyl)5], while the latter contains a tridentate ligand that is formed from the `coupling' of six CNXyl ligands. A third crystal structure from this reaction, (7-methylindol-1-ido-κN)(1,4,7,10,13,16-hexaoxacyclooctadecane-κ6 O)potassium, [K(C9H8N)(C12H24O6)] or [K(C9H8N)(18-crown-6)], contains a 7-methylindol-1-ide anion, in which one CNXyl ligand has shed a proton during its reductive cyclization.

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.

scholarly journals Neutron and X-ray powder diffraction study of skutterudite thermoelectrics

2016 ◽  
Vol 31 (1) ◽  
pp. 16-22
Author(s):  
H. Wang ◽  
M. J. Kirkham ◽  
T. R. Watkins ◽  
E. A. Payzant ◽  
J. R. Salvador ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Melt Spinning ◽  
Lattice Parameter ◽  
Type Material ◽  
General Motors ◽  
X Ray Diffraction ◽  
Filling Fraction ◽  
Cubic Symmetry ◽  
X Ray ◽  
P Type

N- and p-type filled-skutterudite materials prepared for thermoelectric power generation modules were analyzed by neutron diffraction at the POWGEN beam line of the Spallation Neutron Source (SNS) and X-ray diffraction (XRD). The skutterudite powders were processed by melt spinning, followed by ball milling and annealing. The n-type material consists of Ba–Yb–Co–Sb and the p-type material consists of Di–Fe–Ni–Sb or Di–Fe–Co–Sb (Di = didymium, an alloy of Pr and Nd). Powders for prototype module fabrication from General Motors and Marlow Industries were analyzed in this study. XRD and neutron diffraction studies confirm that both the n- and p-type materials have cubic symmetry. Structural Rietveld refinements determined the lattice parameters and atomic parameters of the framework and filler atoms. The cage filling fraction was found to depend linearly on the lattice parameter, which in turn depends on the average framework atom size. This knowledge may allow the filling fraction of these skutterudite materials to be purposefully adjusted, thereby tuning the thermoelectric properties.

Crystal structures of some eriostyl/nitrobenzoate derivatives

1980 ◽  
Vol 33 (2) ◽  
pp. 313 ◽  
Author(s):  
PR Jefferies ◽  
BW Skelton ◽  
B Walter ◽  
AH White
Keyword(s):  
Charge Transfer ◽  
Solid State ◽  
Single Crystal ◽  
Crystal Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Determinations

Following the suggestion made earlier, on the basis of solution spectroscopy, that a number of eriostyl/nitrobenzoate compounds form charge-transfer self-complexes, a number of these have been investigated structurally by single-crystal X-ray diffraction methods in order to ascertain the presence or otherwise of such interactions in the solid state. The substances thus studied were eriostyl 3,5-dinitrobenzoate (1), eriostyl p-nitrobenzoate (2), tetrahydroeriostyl 3,5-dinitrobenzoate (3), and eriostemyl 3,5-dinitrobenzoate (4);* structure determinations in all cases, although displaying the presence of strong charge-transfer interactions from the two moieties of each molecule, show that the interactions in the solid state are intermolecular in nature.

scholarly journals Darstellung und Kristallstrukturen von (PH4P)4Sb8I28 und (Ph4P)Sb3I10(Ph = C6H5) / Synthesis and Crystal Structures of (PH4P)4Sb8I28 and (Ph4P)Sb3I10(Ph = C6H5)

1987 ◽  
Vol 42 (12) ◽  
pp. 1493-1499 ◽  
Author(s):  
Siegfried Pohl ◽  
Wolfgang Saak ◽  
Detlev Haase
Keyword(s):  
Single Crystal ◽  
Crystal Structures ◽  
Diffraction Data ◽  
Lone Pair ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Molar Ratios ◽  
Polymeric Chains ◽  
Bond Strengths

AbstractThe compounds (Pn4P)4Sb8I28 (1) and (Ph4P)Sb3I10 (2) were prepared by the reaction of SbI3 and Ph4PI in acetonitrile (molar ratios 2:1 and 3:1 respectively). The structures of 1 and 2 were determined from single crystal X-ray diffraction data.1 crystallizes in the triclinic space group P1̄ with a - 1321.7(5). b = 1346.7(5), c = 2201.8(8) pm, α = 104.18(2). β = 99.92(2), γ = 100.33(2)°; 2: monoclinic, C2/c, a = 2371.1(2), b = 745.0(1), c = 2495.1(2) pm, β = 100.75(1)°.Whereas 1 exhibits isolated Sb8I284- ions, the anions of 2 are built up of polymeric chains [Sb3I10- ]∞. In both compounds the distorted Sbl6 octahedra are linked by common edges. The Sb-I distances are in the range between 277.4 and 354.8 pm (1) and between 277.4 and 342.4 pm (2). The observed structures do not only depend on stoichiometry, the nature of the counter cations, and the possibility of oligomerisation but also on the wide variety of the Sb-I bond strengths and the different bridges formed by iodine.The lone pair of Sb(III) seems to be predominantly 5 s2.

Sign in / Sign up

Export Citation Format

Share Document