Quaternary Derivatives of the Structure Type BaHg11

2016 ◽  
Vol 257 ◽  
pp. 64-67
Author(s):  
Nastasia Klymentiy ◽  
Svitlana Pukas ◽  
Roman E. Gladyshevskii
Keyword(s):  
Rare Earth ◽  
Crystal Structures ◽  
Cell Parameter ◽  
Structure Type ◽  
Rich Region ◽  
X Ray ◽  
Arc Melting ◽  
Pearson Symbol ◽  
Metallic Radius ◽  
Derivatives Of

One known and nine new quaternary aluminides in the Al-rich region of R–T–Ag–Al (R = Y, Ce, Pr, Nd, Sm, and Gd, T = V, Nb, Ta, Cr, and Mo) systems were synthesized by arc melting and their crystal structures were studied by X-ray powder diffraction. The crystal structures of the compounds R3T(Ag,Al)20Al12 (R = Ce, Pr, Nd, and Sm, T = V, Nb, Ta, Cr, and Mo) and R3TAgx(Ag,Al)20Al12 (R = Y and Gd, T = Ta) belong to new structure types: Ce3Ta (Ag,Al)20Al12 (Pearson symbol сP36, space group Pm-3m, a = 8.6675(2) Å) and Gd3TaAgx(Ag,Al)20Al12 (сP4912.86, Pm-3m, a = 8.6158(5) Å), respectively. Within the rows of isotypic compounds the unit-cell parameter increases with increasing metallic radius of the rare-earth or d-element atom. The structure type Ce3Ta (Ag,Al)20Al12 (Ce3TaAg7.97Al24.03) is a partly ordered quaternary substitution derivative of the structure type BaHg11, whereas Gd3TaAgx(Ag,Al)20Al12 (Gd3TaAg8.89Al23.25) is a distorted fill-in quaternary substitution variant of the same prototype. The latter can also be described as a derivative of the structure type Y3TaNi6+xAl26.

New Quaternary Compounds R3MnAl3Ge2 (R - Rare Earth)

2019 ◽  
Vol 289 ◽  
pp. 21-27
Author(s):  
Natalia Semuso ◽  
Svitlana Pukas ◽  
Yaroslav O. Tokaychuk ◽  
Roman E. Gladyshevskii
Keyword(s):  
Rare Earth ◽  
Earth Metal ◽  
Structure Type ◽  
Hexagonal Structure ◽  
Cell Parameters ◽  
Arc Melting ◽  
Quaternary Compounds ◽  
Pearson Symbol ◽  
The Family ◽  
Trigonal Prismatic Coordination

Nine new quaternaryR3MnAl3Ge2alumogermanides (R= Sm, Gd-Lu) were synthesized by arc melting and their crystal structures were studied by X-ray powder diffraction. All of the compounds crystallize in hexagonal Y3NiAl3Ge2-type structures: Pearson symbolhP9, space groupP-62m. The unit-cell parameters of the isotypic compounds decrease with decreasing radius of the rare-earth metal. The hexagonal structure type Y3NiAl3Ge2(Z= 1) is a quaternary ordering variant of the binary type Fe2P (Z= 3) and the ternary types β1-K2UF6, Lu3CoGa5, Zr3Cu4Si2(Z= 1), ZrNiAl (Z= 3). It belongs to the family of structures with trigonal prismatic coordination of the small atoms.

Novel Ternary Stannides and Plumbides of Rare-Earth Metals and Titanium with ZrFe6Ge4-Type Structures

2016 ◽  
Vol 257 ◽  
pp. 56-59 ◽  
Author(s):  
Oleksandr Yu. Senchuk ◽  
Yaroslav O. Tokaychuk ◽  
Pavlo Yu. Demchenko ◽  
Roman E. Gladyshevskii
Keyword(s):  
Rare Earth ◽  
Data Structure ◽  
Rare Earth Metals ◽  
Structure Type ◽  
Crystallographic Direction ◽  
Powder Diffraction Data ◽  
Coordination Polyhedra ◽  
Ternary Compounds ◽  
Arc Melting ◽  
Pearson Symbol

Eleven new ternary compounds RTi6Sn4 (R = La-Nd, Sm) and RTi6Pb4 (R = Y, Gd-Er) were synthesized by arc-melting under purified argon. The crystal structures were refined from Xray powder diffraction data (structure type ZrFe6Ge4, Pearson symbol hR33, space group R-3m (#166)). They can be described as a stacking of layers formed by the coordination polyhedra of the Sn (Pb) atoms along the crystallographic direction [001].

New compound Sm2Ru3Sn5 with a structure derived from Ru3Sn7

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vera Pavlova ◽  
Elena Murashova
Keyword(s):  
Intermetallic Compound ◽  
Cell Parameter ◽  
X Ray Diffraction ◽  
Crystallographic Site ◽  
Space Group ◽  
X Ray ◽  
Arc Melting ◽  
Pearson Symbol ◽  
Cubic System ◽  
Ternary Intermetallic Compound

Abstract Ternary intermetallic compound Sm2Ru3Sn5 was synthesized in the system Sm-Ru-Sn by arc-melting and annealing at 600 °C in the field with high content of Sn. Its crystal structure was determined using single crystal X-ray diffraction data (at 240 K). The compound crystallizes in cubic system with space group I 4 ‾ 3m (No. 217), unit cell parameter is a = 9.4606 (8) Å, Z = 4, Pearson symbol c/40. The intermetallic compound Sm2Ru3Sn5 represents an ordered version of the centrosymmetric Ru3Sn7 structure (space group Im 3 ‾ m), in which 16f Sn-filled crystallographic site is split into two 8c sites, each of which is solely occupied of one sort of atoms – Sn or Sm. The occupation of these two 8c sites leads to a reduction of symmetry due to the removal of the inversion center.

scholarly journals Computational Chemistry-Guided Syntheses and Crystal Structures of the Heavier Lanthanide Hydride Oxides DyHO, ErHO, and LuHO

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 750
Author(s):  
Nicolas Zapp ◽  
Denis Sheptyakov ◽  
Holger Kohlmann
Keyword(s):  
Rare Earth ◽  
Solid State ◽  
Computational Chemistry ◽  
Crystal Structures ◽  
Functional Materials ◽  
Structure Type ◽  
Solid State Reactions ◽  
X Ray ◽  
Synthesis Conditions ◽  
Phase Width

Heteroanionic hydrides offer great possibilities in the design of functional materials. For ternary rare earth hydride oxide REHO, several modifications were reported with indications for a significant phase width with respect to H and O of the cubic representatives. We obtained DyHO and ErHO as well as the thus far elusive LuHO from solid-state reactions of RE2O3 and REH3 or LuH3 with CaO and investigated their crystal structures by neutron and X-ray powder diffraction. While DyHO, ErHO, and LuHO adopted the cubic anion-ordered half-Heusler LiAlSi structure type (F4¯3m, a(DyHO) = 5.30945(10) Å, a(ErHO) = 5.24615(7) Å, a(LuHO) = 5.171591(13) Å), LuHO additionally formed the orthorhombic anti-LiMgN structure type (Pnma; LuHO: a = 7.3493(7) Å, b = 3.6747(4) Å, c = 5.1985(3) Å; LuDO: a = 7.3116(16) Å, b = 3.6492(8) Å, c = 5.2021(7) Å). A comparison of the cubic compounds’ lattice parameters enabled a significant distinction between REHO and REH1+2xO1−x (x < 0 or x > 0). Furthermore, a computational chemistry study revealed the formation of REHO compounds of the smallest rare earth elements to be disfavored in comparison to the sesquioxides, which is why they may only be obtained by mild synthesis conditions.

The crystal structures of α-Rb7Sb3Br16, α- and β-Tl7Bi3Br16 and their relationship to close packings of spheres

2020 ◽  
Vol 235 (8-9) ◽  
pp. 255-261 ◽  
Author(s):  
Jen-Hui Chang ◽  
Thomas Doert ◽  
Michael Ruck
Keyword(s):  
Aqueous Solutions ◽  
Crystal Structures ◽  
Structure Type ◽  
Structural Features ◽  
Close Packing ◽  
Stacking Sequence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pearson Symbol ◽  
Solvent Free Synthesis

AbstractYellow prismatic crystals of rubidium bromido-antimonate(III) Rb7Sb3Br16 and of two different modifications of thallium bromido-bismuthate(III) Tl7Bi3Br16 were obtained by solvent-free synthesis and by precipitation from acidic aqueous solutions. X-ray diffraction analyses revealed the Tl7Bi3I16-type for α-Tl7Bi3Br16 (orthorhombic, Cmcm, a = 2324.31(8) pm, b = 1346.69(4) pm, c = 3460.0(1) pm; Pearson symbol oC312) and a new structure type for β-Tl7Bi3Br16 (monoclinic, C2/c, a = 2331.87(5) pm, b = 1343.33(3) pm, c = 3546.01(7) pm, β = 102.708(1)°; mC312). The antimonate Rb7Sb3Br16 adopts the Tl7Bi3I16-type, too (orthorhombic, Cmcm, a = 2347.16(3) pm, b = 1357.89(5) pm, c = 3539.47(9) pm; oC312). The crystal structures of α- and β-Tl7Bi3Br16 comprise alternating slabs of isolated [BiBr6]3– octahedra and [Bi2Br10]4– octahedra pairs. Both structure types are hierarchically organized and can be regarded as sphere close packing with the same stacking sequence, if octahedra and octahedra pairs are replaced by spheres of equal size. The structural relationship between the Tl7Bi3I16-type and the hydrate Na7Bi3Br16 · 18H2O, which comprises similar structural features, is discussed.

Crystal structure and local order in Co6Al11−x Si6+x

2007 ◽  
Vol 63 (4) ◽  
pp. 551-560 ◽  
Author(s):  
Klaus W. Richter ◽  
Yurii Prots ◽  
Horst Borrmann ◽  
Reiner Ramlau ◽  
Yuri Grin
Keyword(s):  
Model Space ◽  
Structure Type ◽  
Local Order ◽  
X Ray Diffraction ◽  
Metal Compounds ◽  
Space Group ◽  
X Ray ◽  
Arc Melting ◽  
Transmission Electron ◽  
Pearson Symbol

The ternary compound Co6Al_{11-x}Si_{6+x} (∊ phase) was prepared from the elements by arc melting and subsequent heat treatment, and then characterized by single-crystal X-ray diffraction (XRD), electron-probe microanalysis (EPMA), differential thermal analysis (DTA) and transmission electron microscopy (TEM). This new structure type consists of planar layers with the composition [Co6Al10Si4], which are penetrated by perpendicular (Si—Si—Al) chains. While the layers are well described by an orthorhombic model (space group Pnma, Pearson symbol oP46), the chains exhibit doubled periodicity, thus yielding a superstructure. Two alternative ordering models (space group Cmc21, oC184, and space group P21/c, mP92) are presented and discussed based on XRD and TEM results. The (Si—Si—Al) chains are located in pentagonal antiprismatic `channels' which reveal the similarity of the Co6Al_{11-x}Si_{6+x} structure to Al-rich transition-metal compounds such as Co4Al13, Co2Al5, Fe4Al13, V7Al45, V4Al23 and VAl10, which also exhibit this type of pentagonal `channels' in their crystal structures. The phase shows only a very small homogeneity range.

Preparation and Crystal Structure of the Isotypic Carbides Ln3.67TC6 (Ln = rare earth elements; T = Mn, Fe, Ru) and Eu3,16NiC6

1996 ◽  
Vol 51 (2) ◽  
pp. 249-256 ◽  
Author(s):  
Anne M. Witte ◽  
Wolfgang Jeitschko
Keyword(s):  
Crystal Structure ◽  
Magnetic Susceptibility ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Single Crystal ◽  
Crystal Structures ◽  
Variable Parameters ◽  
X Ray ◽  
Arc Melting ◽  
Structure Factors

Abstract The 14 carbides Ln3.67MnC6 (Ln = La-Nd) and Ln3.67TC6 (Ln = La-Nd, Sm; T = Fe, Ru) were prepared from the elemental components by arc-melting and subsequent annealing. Eu3.16NiC6 was obtained from a lithium flux. The crystal structures of these nearly isotypic, hexagonal compounds (P63/m, Z = 2) were determined from single-crystal X-ray data; La3.67- FeC6: a = 878.7(2), c = 535.1(1) pm, R = 0.052 for 548 structure factors and 25 variable parameters; Eu3.16NiC6: a -860.0(1), c = 548.2(2) pm, R = 0.015 for 606 structure factors and 25 variables. The structures differ from the previously reported Gd3Mn2C6 structure by the occupancy of one manganese position by rare earth atoms. Since the lanthanum atoms are larger than the manganese atoms, only two thirds of these manganese positions can be occupied by the lanthanum atoms in La3.67FeC6. Eu3.16NiC6 has similar atomic positions. The C-C bond distances in the C2 pairs are 130(2) and 126.5(5) pm in the La and Eu compounds, respectively. Magnetic susceptibility measurements with a SQUID magnetometer indicate La3.67FeC6 to be Pauli paramagnetic. A test for superconductivity was negative down to 3 K.

The Stannides RE2Ni2Sn (RE = Pr, Ho, Er, Tm) – Structural Transition from the W2B2Co to the Mo2B2Fe Type as a Function of the Rare Earth Size

2013 ◽  
Vol 68 (1) ◽  
pp. 10-16 ◽  
Author(s):  
Birgit Heying ◽  
Ute Ch. Rodewald ◽  
Bernard Chevalier
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Single Crystal ◽  
Earth Element ◽  
Structural Transition ◽  
Structure Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Arc Melting ◽  
The Rare Earth

The stannides RE2Ni2Sn (RE=Pr, Ho, Er, Tm) were synthesized by arc-melting of the elements and characterized by powder X-ray diffraction. Pr2Ni2Sn crystallizes with the orthorhombic W2B2Co-type structure, Immm, a=443.8(1), b=572.1(1), c=855.1(2) pm, wR2=0.0693, 293 F2 values, 13 variables. A structural transition to the tetragonal Mo2B2Fe type occurs for the heavier rare earth elements. The structures of Ho2Ni2Sn (a=729.26(9), c=366.66(7) pm, wR2=0.0504, 250 F2 values, 12 variables), Er2Ni2Sn (a=727.2(2), c=364.3(1) pm, wR2=0.0397, 262 F2 values, 12 variables), and Tm2Ni2Sn (a=725.2(1), c=362.8(1) pm, wR2=0.0545, 258 F2 values, 12 variables) were refined from single-crystal diffractometer data. The switch in structure type is driven by the size of the rare earth element. The [Ni2Sn] substructures are composed of Ni2Sn2 squares and Ni4Sn2 hexagons in Pr2Ni2Sn, and of Ni3Sn2 pentagons in Er2Ni2Sn. The Ni4Sn2 hexagons and Ni3Sn2 pentagons exhibit Ni2 pairs with Ni-Ni distances of 247 pm in Pr2Ni2Sn, and of 250 pm in Er2Ni2Sn.

The Through-Bond Interaction of a Sulfur Lone Pair with Oxygenated Substituents in the Thiacyclohexane Framework

2005 ◽  
Vol 58 (7) ◽  
pp. 531
Author(s):  
Laura Andrau ◽  
Jonathan M. White
Keyword(s):  
Low Temperature ◽  
Crystal Structures ◽  
Bond Distance ◽  
Lone Pair ◽  
X Ray ◽  
Ester Derivative ◽  
Bond Interaction ◽  
Derivatives Of ◽  
Electron Demand

Low-temperature X-ray crystal structures were determined on a range of derivatives of 4-thiacyclohexanol 5a of varying electron demand with a view to finding evidence for a through-bond interaction between the sulfur lone pair and the oxygenated substituent. In contrast to earlier suggestions, plots of C–OR bond distance versus pKa (ROH) showed that any interaction between the sulfur and the OR group is unlikely to be of a through-bond origin. Furthermore, unimolecular solvolysis rate measurements on the nosylate ester derivative 5g showed that the sulfur actually retards the reaction slightly in comparison with the corresponding sulfur-free analogue 6.

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.

Sign in / Sign up

Export Citation Format

Share Document