SrCo2Sn8 and BaCo2Sn8: Tin-rich Stannides with Distorted SnSn6 Octahedra within Three-dimensional [Co2Sn8] Networks

2013 ◽  
Vol 68 (1) ◽  
pp. 17-22 ◽  
Author(s):  
Christian Schwickert ◽  
Rainer Pöttgen
Keyword(s):  
Three Dimensional ◽  
Structure Type ◽  
Temperature Dependent ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Dimensional Network ◽  
Covalently Bonded ◽  
Distorted Octahedral ◽  
Pauli Paramagnetism ◽  
Tin Coordination

The tin-rich stannides SrCo2Sn8 and BaCo2Sn8 were synthesized from the elements in sealed tantalum tubes. They crystallize with a new structure type, space group Cccm with a=1006.0(3), b=1514.4(6), c=1385.0(6) pm for SrCo2Sn8 and a=1032.8(2), b=1516.8(3), c=1405.1(3) pm for BaCo2Sn8. The structure of the barium compound was refined on the basis of single-crystal Xray diffractometer data: wR2=0.0450, 1715 F2 values, 57 variables. The cobalt atoms have seven nearest tin neighbors with Co-Sn distances ranging from 257 to 273 pm. These CoSn7 units are condensed via common rectangular faces to [Co2Sn10] double units which build up a covalently bonded three-dimensional network through Sn-Co-Sn bridges. Larger voids left by this network are filled by the barium and the Sn2 atoms. The latter have distorted octahedral tin coordination with Sn2- Sn distances of 311 - 315 pm. The barium atoms have 13 nearest tin neighbors (352 - 399 pm Ba-Sn). Temperature-dependent magnetic susceptibility data of BaCo2Sn8 show Pauli paramagnetism.

Intermediate-valent Cerium in CeRu2Mg5

2010 ◽  
Vol 65 (10) ◽  
pp. 1185-1190 ◽  
Author(s):  
Stefan Linsinger ◽  
Matthias Eul ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen
Keyword(s):  
High Frequency ◽  
Three Dimensional ◽  
Magnetic Ordering ◽  
Structure Type ◽  
Formula Unit ◽  
Temperature Dependent ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Intermediate Valent ◽  
Cerium Atom

The magnesium-rich compound CeRu2Mg5 was synthesized by high-frequency melting of the elements in a sealed tantalum ampoule. CeRu2Mg5 crystallizes with a new tetragonal structure type: P42/ncm, a = 961.1(1), c = 723.2(1) pm, wR2 = 0.0284, 481 F2 values and 25 variables. The striking structural motifs in CeRu2Mg5 are short Ce-Ru distances of 232 pm. Each cerium atom is connected to two ruthenium atoms within a three-dimensional [Ru2Mg5] network. CeRu2Mg5 has a pronounced magnesium substructure with short Mg-Mg distances in the range 302 - 341 pm. The short Ce-Ru distances are a consequence of the almost tetravalent character of the cerium atoms. Temperature-dependent magnetic susceptibility data show intermediate-valent behavior of the cerium atoms (0.9(1) μB per formula unit) and no magnetic ordering down to 3 K.

Bismuth Flux Growth of CeRh6Ge4 and CeRh2Ge2 Single Crystals

2012 ◽  
Vol 67 (12) ◽  
pp. 1241-1247 ◽  
Author(s):  
Daniel Voßwinkel ◽  
Oliver Niehaus ◽  
Ute Ch. Rodewald ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystals ◽  
Three Dimensional ◽  
Magnetic Ordering ◽  
Field Measurements ◽  
Temperature Dependent ◽  
Magnetic Susceptibility Data ◽  
Susceptibility Data ◽  
Low Field ◽  
Arc Melting ◽  
Covalently Bonded

Single crystals of the germanides CeRh6Ge4 and CeRh2Ge2 were synthesized from the elements in bismuth fluxes. Polycrystalline samples are available by arc-melting. The structures were refined on the basis of single-crystal X-ray diffractometer data. CeRh6Ge4: LiCo6P4 type, P6m2, a=715.4(2), c=385:5(1) pm, wR2=0.0554, 273 F2 values, 19 variables; CeRh2Ge2: ThCr2Si2 type, I4/mmm, a=415.69(6), c=1048:5(2) pm, wR2=0.0391, 131 F2 values, 9 variables. The rhodium and germanium atoms build three-dimensional, covalently bonded [Rh6Ge4] and [Rh2Ge2] networks with Rh-Ge distances ranging from 246 to 255 pm. The cerium atoms are located in larger cavities within these networks: Ce@Ge6Rh12 in CeRh6Ge4 and Ce@Ge8Rh8 in CeRh2Ge2. Temperature-dependent magnetic susceptibility data of CeRh6Ge4 show Curie-Weiss behavior above 70 K with an experimental magnetic moment of 2:35(1) μB per Ce atom. Low-field measurements are indicative of magnetic ordering below 2:5 K.

Ternary Indides REMgIn (RE = Y, La–Nd, Sm, Gd–Tm, Lu). Synthesis, Structure and Magnetic Properties

2004 ◽  
Vol 59 (5) ◽  
pp. 513-518 ◽  
Author(s):  
Rainer Kraft ◽  
Martin Valldor ◽  
Daniel Kurowski ◽  
Rolf-Dieter Hoffmann ◽  
Rainer Pöttgen
Keyword(s):  
Magnetic Moments ◽  
Three Dimensional ◽  
Temperature Dependent ◽  
Variable Parameters ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Sample Chamber ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

Abstract The equiatomic rare earth-magnesium-indium compounds REMgIn (RE = Y, La-Nd, Sm, Gd- Tm, Lu) were prepared from the elements in sealed tantalum tubes inside a water-cooled sample chamber of an induction furnace. All compounds were characterized through their X-ray powder patterns. They crystallize with the hexagonal ZrNiAl type structure, space group P6̄̄2m, with three formula units per cell. The structure of SmMgIn was refined from X-ray single crystal diffractometer data: a = 761.3(2), c = 470.3(1) pm, wR2 = 0.0429, 380 F2 values and 14 variable parameters. The DyMgIn, HoMgIn, and TmMgIn structures have been analyzed using the Rietveld technique. The REMgIn structures contain two cystallographically independent indium sites, both with tri-capped trigonal prismatic coordination: In1Sm6Mg3 and In2Mg6Sm3. Together the magnesium and indium atoms form a three-dimensional [MgIn] network with Mg-Mg distances of 320 and Mg-In distances in the range 294 - 299 pm. Temperature dependent magnetic susceptibility data show Curie-Weiss behavior for DyMgIn, HoMgIn, and TmMgIn with experimental magnetic moments of 11.0(1) μB/Dy atom, 10.9(1) μB/Ho atom, and 7.5(1) μB/Tm atom. The three compounds order antiferromagnetically at TN = 22(2) K (DyMgIn), 12(1) K (HoMgIn), and 3(1) K (TmMgIn).

The equiatomic intermetallics REPtCd (RE= La, Ce, Pr, Nd, Eu) and magnetic properties of CeAuCd

2015 ◽  
Vol 70 (3) ◽  
pp. 197-202 ◽  
Author(s):  
Michael Johnscher ◽  
Frank Tappe ◽  
Oliver Niehaus ◽  
Rainer Pöttgen
Keyword(s):  
Phase Transition ◽  
Three Dimensional ◽  
Induction Melting ◽  
Antiferromagnetic Phase ◽  
Crystal Data ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data

AbstractThe cadmium intermetallics REPtCd (RE = La, Ce, Pr, Nd, Eu) and CeAuCd were synthesized by induction-melting of the elements in sealed niobium ampoules followed by annealing in muffle furnaces. The samples were characterized by powder X-ray diffraction. The structures of CePtCd (ZrNiAl type, $P\bar 62m,$a = 763.8(6), c = 409.1(4) pm, wR2 = 0.0195, 298 F2 values, 14 variables) and EuPtCd (TiNiSi type, Pnma, a = 741.3(2), b = 436.4(1), c = 858.0(4) pm, wR2 = 0.0385, 440 F2 values, 20 variables) were refined from single-crystal data. The REPtCd structures exhibit three-dimensional networks of corner- and edge-sharing Cd@Pt2/6Pt2/3 and Cd@Pt4/4 tetrahedra, which leave cages for the rare earth atoms. Temperature-dependent magnetic susceptibility data of CeAuCd reveal a paramagnetic to antiferromagnetic phase transition at TN = 3.7(5) K.

Isosymmetrical phase transition in α-YbV4O8

2008 ◽  
Vol 64 (6) ◽  
pp. 652-660 ◽  
Author(s):  
Karen Friese ◽  
Yasushi Kanke ◽  
Andy N. Fitch ◽  
Wolfgang Morgenroth ◽  
Andrzej Grzechnik
Keyword(s):  
Phase Transition ◽  
Three Dimensional ◽  
Structure Type ◽  
Charge Ordering ◽  
Gap Formation ◽  
Magnetic Susceptibility Data ◽  
First Order ◽  
Susceptibility Data ◽  
Transition Mechanism ◽  
Α Phase

The structure of YbV4O8 is related to the CaFe2O4 structure type. VO6 octahedra form a three-dimensional framework with tunnels in which the Yb3+ ions are incorporated. Two different polymorphs α and β are known and differ mainly in the arrangement of the Yb ions within the framework. We studied the structure and magnetic properties of α-YbV4O8 as a function of temperature. At approximately 70 K α-YbV4O8 undergoes a first-order isosymmetrical phase transition (P21/n → P21/n). While in the high-temperature α phase the three V3+ and one V4+ are disordered over the four symmetrically independent octahedral sites, in the low-temperature α′ phase complete charge ordering is observed. The transition is accompanied by a paramagnetic–paramagnetic anomaly in the magnetic susceptibility data which can be interpreted on the basis of spin-gap formation. The transition mechanism in the α polymorph is very similar to that observed earlier in the β polymorph at 185 K.

Equiatomic rare earth rhodium plumbides RERhPb (RE=Y, La–Nd, Sm, Gd–Lu) with ZrNiAl-type structure

2018 ◽  
Vol 73 (3-4) ◽  
pp. 251-258
Author(s):  
Lukas Heletta ◽  
Rainer Pöttgen
Keyword(s):  
Type Structure ◽  
Induction Melting ◽  
Temperature Dependent ◽  
Magnetic Susceptibility Data ◽  
X Ray ◽  
Susceptibility Data ◽  
Pauli Paramagnetism ◽  
Antiferromagnetic Ground State ◽  
Trigonal Prismatic Coordination ◽  
Trigonal Prismatic

AbstractThe equiatomic plumbidesRERhPb (RE=Y, La–Nd, Sm, Gd–Lu) were synthesized by induction melting of the elements in sealed niobium ampoules. The samples were characterized by X-ray powder diffraction, confirming their ZrNiAl-type structure, space groupP6̅2m. Four structures were refined from single-crystal X-ray diffractometer data:a=769.42(5),c=415.60(3) pm,wR=0.0415, 343F2values, 15 variables for LaRhPb,a=767.91(6),c=369.37(4) pm,wR=0.0798, 284F2values, 15 variables for ErRhPb,a=767.01(8),c=366.21(4) pm,wR=0.0380, 341F2values, 15 variables for YbRhPb anda=766.9(1),c=363.42(6) pm,wR=0.0699, 290F2values, 15 variables for LuRhPb. TheRERhPb plumbides contain two crystallographically independent rhodium atoms, both in tricapped trigonal prismatic coordination: Rh1@Pb3RE6and Rh2@RE6Pb3. Short Rh–Pb distances (277 and 284 pm in ErRhPb) are indicative of covalent Rh–Pb bonding. The crystal chemical details of theRERhPb series are compared with the silver plumbidesREAgPb which show different transition metal-lead coloring. Temperature dependent magnetic susceptibility data show Pauli paramagnetism for YRhPb, LaRhPb and LuRhPb. An antiferromagnetic ground state below the Néel temperatures of 13.5, 21.0 and 6.9 K was found for PrRhPb, TbRhPb and DyRhPb, respectively. HoRhPb exhibits Curie-Weiss behavior in the observed temperature range.

scholarly journals Crystal structure ofcatena-poly[[diaquabis(4-formylbenzoato-κO1)cobalt(II)]-μ-pyrazine-κ2N:N′]

2015 ◽  
Vol 71 (4) ◽  
pp. 339-341 ◽  
Author(s):  
Gülçin Şefiye Aşkın ◽  
Fatih Çelik ◽  
Nefise Dilek ◽  
Hacali Necefoğlu ◽  
Tuncer Hökelek
Keyword(s):  
Hydrogen Bonds ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Water Molecules ◽  
Carboxylate Group ◽  
Polymeric Compound ◽  
Distorted Octahedral Coordination ◽  
Linear Chains ◽  
Dimensional Network ◽  
Distorted Octahedral

In the title polymeric compound, [Co(C8H5O3)2(C4H4N2)(H2O)2]n, the CoIIatom is located on a twofold rotation axis and has a slightly distorted octahedral coordination sphere. In the equatorial plane, it is coordinated by two carboxylate O atoms of two symmetry-related monodentate formylbenzoate anions and by two N atoms of two bridging pyrazine ligands. The latter are bisected by the twofold rotation axis. The axial positions are occupied by two O atoms of the coordinating water molecules. In the formylbenzoate anion, the carboxylate group is twisted away from the attached benzene ring by 7.50 (8)°, while the benzene and pyrazine rings are oriented at a dihedral angle of 64.90 (4)°. The pyrazine ligands bridge the CoIIcations, forming linear chains running along theb-axis direction. Strong intramolecular O—H...O hydrogen bonds link the water molecules to the carboxylate O atoms. In the crystal, weak O—Hwater...Owaterhydrogen bonds link adjacent chains into layers parallel to thebcplane. The layers are linkedviaC—Hpyrazine...Oformylhydrogen bonds, forming a three-dimensional network. There are also weak C—H...π interactions present.

3D-[Pr(Im)3(ImH)]@ImH: Ein dreidimensionales Netzwerk mit vollständiger Stickstoffkoordination aus einer Imidazolschmelze / 3D-[Pr(Im)3(ImH)]@ImH: A Three-Dimensional Network with Complete Nitrogen Coordination Obtained from an Imidazole Melt

2006 ◽  
Vol 61 (7) ◽  
pp. 792-798 ◽  
Author(s):  
Klaus Müller-Buschbaum
Keyword(s):  
Crystal Engineering ◽  
Material Science ◽  
Three Dimensional ◽  
Temperature Dependent ◽  
Temperature Synthesis ◽  
3 Dimensional ◽  
High Temperature Synthesis ◽  
Dimensional Network ◽  
Bright Green ◽  
Gas Molecules

The reaction of a melt of unsubstituted imidazole with praseodymium metal yields bright green crystals of 3D-[Pr(Im)3(ImH)]@ImH. Imidazolate ligands coordinate η1 via both N atoms their 1,3 positioning within the heterocycle being responsible for the connection of praseodymium atoms. A 3-dimensional network is formed with imidazole molecules from the melt intercalated in the crystal structure. The imidazole molecules can be released and temperature dependent reversibly be exchanged with gas molecules including argon. Thus the solvent free high temperature synthesis of rare earth elements with amine melts can also be utilized for “crystal engineering” and the synthesis of compounds with material science aspects. Furthermore 3D-[Pr(Im)3(ImH)]@ImH is the first unsubstituted imidazolate of the lanthanides.

scholarly journals Crystal structure of 2-methyl-1H-imidazol-3-ium aquatrichlorido(oxalato-κ2O,O′)stannate(IV)

2015 ◽  
Vol 71 (5) ◽  
pp. 520-522 ◽  
Author(s):  
Mouhamadou Birame Diop ◽  
Libasse Diop ◽  
Laurent Plasseraud ◽  
Thierry Maris
Keyword(s):  
Hydrogen Bonds ◽  
Water Molecule ◽  
Three Dimensional ◽  
Free Oxygen ◽  
Coordination Environment ◽  
Dimensional Network ◽  
Oxalate Ligand ◽  
Distorted Octahedral ◽  
Distorted Octahedral Coordination Environment ◽  
Oxygen Atoms

The tin(IV) atom in the complex anion of the title salt, (C4H7N2)[Sn(C2O4)Cl3(H2O)], is in a distorted octahedral coordination environment defined by three chlorido ligands, an oxygen atom from a water molecule and two oxygen atoms from a chelating oxalate anion. The organic cation is linked through a bifurcated N—H...O hydrogen bond to the free oxygen atoms of the oxalate ligand of the complex [Sn(H2O)Cl3(C2O4)]−anion. Neighbouring stannate(IV) anions are linked through O—H...O hydrogen bonds involving the water molecule and the two non-coordinating oxalate oxygen atoms. In combination with additional N—H...Cl hydrogen bonds between cations and anions, a three-dimensional network is spanned.

scholarly journals catena-Poly[bis(1,3-benzothiazol-3-ium) [[dichloridoantimonate(III)]-di-μ-chlorido-μ-oxido-[chloridoantimonate(III)]-μ-chlorido]]

2016 ◽  
Vol 72 (2) ◽  
pp. 212-214
Author(s):  
Oussama Chebout ◽  
Mhamed Boudraa ◽  
Sofiane Bouacida ◽  
Hocine Merazig ◽  
Chaouki Boudaren
Keyword(s):  
Crystal Packing ◽  
Three Dimensional ◽  
Organic Cations ◽  
Ionic Structure ◽  
Compound C ◽  
Dimensional Network ◽  
Inorganic Cation ◽  
Distorted Octahedral ◽  
Common Face ◽  
Cl Atoms

The title compound, {(C7H6NS)2[Sb2Cl6O]}n, contains two benzothiazolidium cations and one tri-μ-chlorido-trichlorido-μ-oxido-diantimonate(III) anion. The structure of the inorganic cation may be described as as being built up from two polyhedra,i.e.a square-pyramidal SbCl4O and a distorted octahedral SbOCl5unit, sharing a common face (comprising the O atom and two Cl atoms). The two benzothiazole cations are quasi-planar and subtend a dihedral angle of 19.93 (5)°. The crystal packing can be described by alternating (100) layers and [001] chains of the organic cations and inorganic anions connected through an extensive three-dimensional network of N—H...Cl, C—H...O and C—H...Cl hydrogen bonds. This is consolidated by slipped π–π stacking, with centroid-to-centroid distances between the benzothiazole rings of 3.7111 (18)–3.8452 (16) Å. These interactions link the molecules within the layers and also link the layers together and reinforce the cohesion of the ionic structure.

Sign in / Sign up

Export Citation Format

Share Document