La3Cl3BC – Structure, Bonding and Electrical Conductivity

2005 ◽  
Vol 60 (5) ◽  
pp. 499-504 ◽  
Author(s):  
Hui-Yi Zeng ◽  
Hiroki Okudera ◽  
Chong Zheng ◽  
Hansjürgen Mattausch ◽  
Reinhard K. Kremer ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Rare Earth ◽  
Monoclinic System ◽  
Space Group ◽  
Valence Electrons ◽  
Trigonal Prismatic Coordination ◽  
Cl Atoms ◽  
Polymeric Anion ◽  
Trigonal Prismatic ◽  
Trigonal Prisms

A new rare earth carbide boride halide, La3Cl3BC, has been prepared by heating a mixture of stoichiometric quantities of LaCl3, La, B and C at 1050 °C for 10 days. La3Cl3BC (La3Br3BC type) crystallizes in the monoclinic system with space group P21/m (No. 11), a = 8.2040(16), b = 3.8824(8), c=11.328(2)Å , β =100.82(3)°. In the structure, monocapped trigonal prisms containing B-C units are condensed into chains along the b direction, and the chains are further linked by Cl atoms in the a and c directions. The condensation results in a polymeric anion 1∞[BC] with a spine of B atoms in a trigonal prismatic coordination by La, and the C atoms attached in a square pyramidal coordination. The B-B and B-C distances are 2.16 and 1.63 Å , respectively. La3Cl3BC is metallic. The EH calculation shows that the distribution of valence electrons can be formulated as (La3+)3(Cl−)3(BC)5− · e−.

Ternary Thallides REMgTl (Re = Y, La – Nd, Sm, Gd – Tm, Lu)

2005 ◽  
Vol 60 (3) ◽  
pp. 265-270 ◽  
Author(s):  
Rainer Kraft ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Rare Earth Metal ◽  
High Frequency ◽  
Three Dimensional ◽  
Earth Metal ◽  
X Ray ◽  
Sample Chamber ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

The rare earth metal (RE)-magnesium-thallides REMgTl (RE = Y, La-Nd, Sm, Gd-Tm, Lu) were prepared from the elements in sealed tantalum tubes in a water-cooled sample chamber of a high-frequency furnace. The thallides were characterized through their X-ray powder patterns. They crystallize with the hexagonal ZrNiAl type structure, space group P62m, with three formula units per cell. Four structures were refined from X-ray single crystal diffractometer data: α = 750.5(1), c = 459.85(8) pm, wR2 = 0.0491, 364 F2 values, 14 variables for YMgTl; α = 781.3(1), c = 477.84(8) pm, wR2 = 0.0640, BASF = 0.09(2), 425 F2 values, 15 variables for LaMgTl; α = 774.1(1), c = 473.75(7) pm, wR2 = 0.0405, 295 F2 values, 14 variables for CeMgTl; a = 760.3(1), c = 465.93(8) pm, wR2 = 0.0262, 287 F2 values, 14 variables for SmMgTl. The PrMgTl, NdMgTl, GdMgTl, TbMgTl, and DyMgTl structures have been analyzed using the Rietveld technique. The REMgTl structures contain two cystallographically independent thallium sites, both with tri-capped trigonal prismatic coordination: Tl1Mg3RE6 and Tl2Mg6RE3. Together the magnesium and thallium atoms form three-dimensional [MgTl] networks with Mg-Mg distances of 327 and Mg-Tl distances in the range 299 - 303 pm (data for CeMgTl)

Ternary Gallides REMgGa (RE = Y, La, Pr, Nd, Sm–Tm, Lu) – Synthesis and Crystal Chemistry

2003 ◽  
Vol 58 (9) ◽  
pp. 827-831 ◽  
Author(s):  
Rainer Kraft ◽  
Martin Valldor ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Single Crystal ◽  
Cell Volume ◽  
Coordination Number ◽  
High Frequency ◽  
Three Dimensional ◽  
Gallium Atom ◽  
X Ray ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

The title compounds have been synthesized by reacting the elements in sealed niobium or tantalum tubes in a high-frequency furnace. They crystallize with the hexagonal ZrNiAl type structure, space group P62m. All gallides have been characterized through their X-ray powder diffractogram. The cell volume decreases from the lanthanum to the lutetium compound as expected from the lanthanoid contraction. The structures of LaMgGa, PrMgGa, NdMgGa, SmMgGa and TmMgGa have been refined from single crystal diffractometer data. The structures contain two crystallographically independent gallium sites which both have a trigonal prismatic coordination: Ga1 by six RE and Ga2 by six Mg atoms. These trigonal prisms are capped on the rectangular sites by three Mg (RE) atoms, leading to coordination number 9 for each gallium atom. Together, the gallium and magnesium atoms form a three-dimensional [MgGa] network in which the rare earth atoms fill distorted hexagonal channels. Within the network the magnesium atoms have short Mg-Mg contacts, i. e. 312 pm in SmMgGa. The Mg-Ga distances in that gallide range from 284 to 287 pm. Bonding in the network is thus governed by strong Mg-Ga and Mg-Mg bonding. EuMgGa crystallizes with the orthorhombic TiNiSi type: Pnma, a = 783.1(2), b = 472.8(1), c = 829.8(2) pm.

Transition Metal-centered Trigonal Prisms as BuildingUnits in RE14T3In3 (RE = Y, Ho, Er, Tm, Lu; T = Pd, Ir, Pt) and Y4IrIn

2007 ◽  
Vol 62 (12) ◽  
pp. 1574-1580 ◽  
Author(s):  
Roman Zaremba ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Transition Metal ◽  
Three Dimensional ◽  
Crystal Chemical ◽  
Crystal Data ◽  
Space Group ◽  
X Ray ◽  
Type Space ◽  
Arc Melting ◽  
Trigonal Prisms

The indides RE14T3In3 (RE = Y, Ho, Er, Tm, Lu; T = Pd, Ir, Pt) and Y4IrIn were synthesized from the elements by arc-melting and subsequent annealing for crystal growth. Their structures were characterized on the basis of X-ray powder and single crystal data: Lu14Co3In3-type, space group P42/nmc, a = 970.2(1), c = 2340.7(5) pm for Y13.95Pd3In3.05, a = 959.7(1), c = 2309.0(5) pm for Ho14Pd2.95In3, a = 955.5(1), c = 2305.1(5) pm for Er14Pd3In3, a = 950.9(1), c = 2291.6(5) pm for Tm13.90Pd3In3.10, a = 944.4(1), c = 2275.5(5) pm for Lu13.93Pd3In3.07, a = 962.9(1), c = 2343.0(5) pm for Y13.86Ir2.97In3.02, a = 967.6(1), c = 2347.8(5) pm for Y13.92Pt3.05In2.91, and Gd4RhIn-type, space group F 4̅3m, a = 1368.6(2) pm for Y4IrIn. The main structural motifs are transition metal-centered trigonal prisms of the rare earth elements which are condensed to twodimensional networks in the RE14T3In3 indides and to a three-dimensional one in Y4IrIn. The indium atoms in both structure types show segregation in the metal-rich matrix, i. e. In2 dumbbells in the RE14T3In3 indides (309 pm In2-In2 in Y13.86Ir2.97In3.02) and In4 tetrahedra (322 pm In-In) in Y4IrIn. The crystal chemical peculiarities of both structure types are discussed.

The Relationship Between Octahedral and Trigonal-Prismatic Coordination in Bis Tridentate Complexes of TiIV and VIV

1988 ◽  
Vol 41 (4) ◽  
pp. 453 ◽  
Author(s):  
AA Diamantis ◽  
M Manikas ◽  
MA Salam ◽  
MR Snow ◽  
ERT Tiekink
Keyword(s):  
Tridentate Ligand ◽  
Vanadium Complexes ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Titanium Complexes ◽  
Tridentate Ligands ◽  
Space Group ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

The crystal structures of two vanadium complexes V( aabh )2 (1) and V( aasalh )2 (2) and of two titanium complexes Ti( aabh )2 (3) and Ti( babh )2 (4), where aabh is the dinegative, tridentate ligand pentane-2,4-dione benzoylhydrazonato (2-), aasalh is pentane-2,4-dione salicyloylhydrazonato (2-) and babh is 4-phenylbutane-2,4-dione benzoylhydrazonato (2-), were determined by X-ray diffraction methods. Crystals of (1) are monoclinic, space group P21/c, a 8.906(3), b 11.840(2), c 22.450(6)Ǻ, β 97.72(3)°, V 2345.8 and Z 4; those of (2) are triclinic, space group Pī , a 9.802(4), b 10.205(3), c 13.688(6)Ǻ, α 100.56(3),β 94.07(4),γ 112.89(3)°, V 1224.6 Ǻ3 and Z 2; those of (3) are monoclinic, space group C2/c, a 18.543(4), b 10.269(4), c 12.589(4)Ǻ, β 106.80(2)°, V 2294.9 Ǻ3 and Z 4; and those of (4) are monoclinic, space group P21/n, a 10.923(4), b 19.139(3), c 14.610(5)Ǻ, β 94.54(3)°, V 3044.7 Ǻ3 and Z 4. The structures were refined by a full-matrix least-squares procedure in each case to final values of R 0.102, 0.044, 0.049 and 0.058 for the structures (1), (2), (3) and (4), respectively, and values of Rw 0.099, 0.049, 0.053 and 0.065 for 1735, 3405, 1185 and 2911 statistically significant reflections, respectively. In the vanadium complexes the coordination geometry is approximately trigonal prismatic, whereas in each of the titanium complexes the two tridentate ligands are in a meridional arrangement with an approximately octahedral coordination. The stabilization of vanadium(IV) in the absence of the oxo function and the role of the metals in producing different coordination geometries are discussed.

Über ein Barium-Lanthanoid-Oxozinkat-Platinat(IV): Ba17Yb16Zn8Pt4O57

1996 ◽  
Vol 51 (2) ◽  
pp. 220-224 ◽  
Author(s):  
Ch. Rabbow ◽  
O. Sfreddo ◽  
Hk. Müller-Buschbaum
Keyword(s):  
Crystal Structure ◽  
Space Group ◽  
Structure Space ◽  
Tetragonal Crystal ◽  
Tetragonal Crystal Structure ◽  
Trigonal Prismatic Coordination ◽  
The Relationship ◽  
Trigonal Prismatic

Abstract Reactions of BaCO3, ZnO and Yb2O3 mixtures at temperatures up to 1300 °C using plati­num crucibles led to yellow needles of Ba17Y b16Zn8Pt4O57. The compound crystallizes with a hitherto unknown tetragonal crystal structure, space group C54h-I4/m, a = 22.731(1), c = 5.682(1) Å , Z = 2. The crystal structure is characterized by PtO6 octahedra and tetragonal ZnO5 pyramids. Yb3+ shows a mono-capped trigonal prismatic coordination and Ba2+ several different coordination environments (C .N = 9 to 10, by O2-). The relationship to the Ba5Ln8M4O21 type is discussed.

Phasenuntersuchungen im System 2 Ha–TaS2–2Hc–MoS2 / Investigations on Phases in the System 2 Ha-TaS2-2Hc-MoS2

1994 ◽  
Vol 49 (9) ◽  
pp. 1175-1178 ◽  
Author(s):  
Peter Remmert ◽  
Edmund Fischer ◽  
Hans-Ulrich Hummel
Keyword(s):  
Electrical Conductivity ◽  
Powder Diffraction ◽  
Higher Order ◽  
Metallic Conductivity ◽  
X Ray ◽  
Thermal Reactions ◽  
Reversible Transition ◽  
System 2 ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

Ternary phases in the system TaS2-MoS2 have been obtained by thermal reactions at 1050 °C of binary layered disulfides and NH4Cl as promotor.Ternary phases Ta1-xMoxS2 exist in the range 0.5 ≤ x ≤ 0.9. In the range of 0.25 ≤ x ≤ 0.55 the reactions are quantitative and the phase-compositions are determined by the amounts of the starting materials. For x < 0 .2 1 T-TaS2 and for x > 0.60 2 Hc-MoS2 are contaminating the resulting ternary phases.Ternary phases have been characterized by X-ray powder diffraction and are indexed rhombohedrally on the basis of a 3 R-structure with metals in trigonal-prismatic coordination. The phases Ta1-xMoxS2 with 0.25 ≤ x ≤ 0.55 show a reversible transition of higher order associated with a change in the electrical conductivity mechanism. Below 420 K the phases show semiconductivity while above 460 K metallic conductivity is observed

scholarly journals A study of nonstoichiometric oxides in the Ln-Ni-O (Ln=La, Pr, Nd) system

2015 ◽  
Vol 3 (2) ◽  
pp. 89-92 ◽  
Author(s):  
Vadim Kulichenko ◽  
Sergiy Nedilko ◽  
Olexander Dziazko ◽  
Victoria Chornovol
Keyword(s):  
Electrical Conductivity ◽  
Rare Earth ◽  
Phase Analysis ◽  
Oxygen Content ◽  
Rare Earth Oxides ◽  
Tetragonal Symmetry ◽  
Space Group ◽  
X Ray ◽  
K2nif4 Structure ◽  
Semiconducting Behavior

The non-stoichiometric compositions Ln2-xNiO4-3x/2+d (Ln=La, Pr, Nd, 0£x£0,4) were obtained using coprecipitation method from nitrates solutions by K2CO3 followed by calcination of the obtained blend at 950°С. According to X-ray phase analysis compositions in the range La2NiO4.17 – La1.6NiO3.63 are monophase and crystallize in tetragonal symmetry K2NiF4, space group I4/mmm. Nd2-xNiO4-y and Pr2-xNiO4-y in the range 0£x£0,2 are monophase and have orthorombic and monoclinic(correspodingly) distorted K2NiF4 structure. Samples with 0,2<x£0,4 are polyphase and contain Ln2NiO4 (Ln=Pr, Nd), NiO and rare earth oxides. Electrical conductivity of obtained samples have semiconducting behavior and it is strong depended to nonstoichiometric oxygen content.

The rare earth metal hydride tellurides REHTe (RE=Y, La–Nd, Gd–Er)

2019 ◽  
Vol 74 (6) ◽  
pp. 513-518
Author(s):  
Matthias Folchnandt ◽  
Daniel Rudolph ◽  
Jean-Louis Hoslauer ◽  
Thomas Schleid
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Rare Earth Metal ◽  
Metal Hydride ◽  
Earth Metal ◽  
Cesium Chloride ◽  
Coordination Pattern ◽  
Trigonal Prismatic Coordination ◽  
Type Crystal ◽  
Trigonal Prismatic

AbstractThe synthesis and crystal structure of a series of rare earth metal hydride tellurides with the composition REHTe (RE = Y, La–Nd, Gd–Er) is reported. These compounds have been obtained by the reaction of rare earth metal dihydrides (REH2) with elemental tellurium in sealed tantalum capsules at T = 700°C using cesium chloride (CsCl) as fluxing agent, which can be washed away with water due to the astonishing insensitivity of these hydride tellurides (REHTe) against hydrolysis. All of the compounds crystallize in the hexagonal space group P6̅m2 with a filled WC-type crystal structure, exhibiting a mutual trigonal-prismatic coordination of the heavy ions (RE3+ and Te2−), while the hydride anions reside in the trigonal prismatic voids surrounded by three rare earth metal cations expanding their coordination pattern to a tricapped trigonal prism. This 1H-type crystal structure is compared with the 1H- and 2H-type structures of the respective hydride selenides (REHSe, RE = Y, La–Nd, Gd–Tm, Lu). Both hexagonal basic crystal structures can be derived from the AlB2-type structure as demonstrated in a Bärnighausen tree by group-subgroup relationships.

scholarly journals Crystal structure of K3EuSi2O7

2021 ◽  
pp. 26-26
Author(s):  
Sabina Kovac ◽  
Predrag Dabic ◽  
Aleksandar Kremenovic
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
X Ray Diffraction ◽  
Coordination Environment ◽  
Distorted Octahedral ◽  
Earth Cation ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic ◽  
The Eu

As a part of the research of the flux technique for growing alkali rare-earth elements (REE) containing silicates, tripotassium europium disilicate, K3EuSi2O7, has been synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in the space group P63/mcm. In the crystal structure of the title compound, one part of the Eu cations are in a slightly distorted octahedral coordination and the other part are in an ideal trigonal prismatic coordination environment. The disilicate Si2O7 groups connect four EuO6 octahedra and one EuO6 trigonal prism. Three differently coordinated potassium cations are located between them. Silicates containing the larger rare earth elements usually crystallize in a structure that contains the rare-earth cation in both a slightly distorted octahedral and an ideal trigonal prismatic coordination environment.

Sign in / Sign up

Export Citation Format

Share Document