ChemInform Abstract: YCa3(CrO)3(BO3)4: A Cr3+ Kagome Lattice Compound Showing No Magnetic Order Down to 2 K.

Polycrystalline gaudefroyite‐type YCa₃(CrO)₃(BO₃)₄ with Cr³⁺ ions (3d³, S = 3/2) forming an undistorted Kagome lattice is prepared by reaction of a stoichiometric mixture of Y₂O₃, CaCO₃, Cr₂O₃, H₃BO₃ in a KCl flux (Al₂O₃ crucible, 1000 °C, 1 d) followed by re‐grinding and further annealing (1000 °C, 2 d, 95% yield).     

ChemInform Abstract: Structural Chemistry and Magnetic Properties of Nd18Li8Fe4M′O39 (M′: Al,Ga) and La18Li8Fe4,5In0.5O39.

The title compounds are prepared by solid state reactions of Nd₂O₃ or La₂O₃, Fe₂O₃, M₂O₃ (M: Al, Ga, In), and excess Li₂CO₃ (alumina crucibles, 800 °C, 16 h).     

ChemInform Abstract: A New n = 4 Layered Ruddlesden—Popper Phase K2.5Bi2.5Ti4O13 Showing Stoichiometric Hydration.

Polycrystalline K_2.5Bi_2.5Ti₄O₁₃ (I) is prepared by solid state reaction of KNO₃, Bi₂O₃, and TiO₂ (Al₂O₃ crucible, 750 °C, 16 h).     

ChemInform Abstract: Pressure‐Induced Structural and Electronic Transition in Sr2ZnWO6 Double Perovskite.

Polycrystalline Sr₂ZnWO₆ is prepared by staged calcination of stoichiometric amounts of SrCO₃, ZnO, and WO₃ in air (Al₂O₃ crucible, 1.     

ChemInform Abstract: Effect of the Framework Flexibility on the Centricities in Centrosymmetric In2Zn(SeO3)4 and Noncentrosymmetric Ga2Zn(TeO3)4.

Crystals of In₂Zn(SeO₃)₄ (I) and Ga₂Zn(TeO₃)₄ (II) are prepared by solid state reaction of ZnO, In₂O₃ or Ga₂O₃, and SeO₂ or TeO₂ (silica tubes, 600—700 °C, 48 h).     

ChemInform Abstract: Syntheses and Properties of a Family of New Compounds RE3Sb3Co2O14 (RE: La,Pr, Nd,Sm—Ho) with an Ordered Pyrochlore Structure.

As an example of the isostructural Ln₃Sb₃Co₂O₁₄ (Ln: La, Pr, Nd, Sm—Ho) series with an ordered pyrochlore structure, the La variant is prepared by a citrate complex method employing stoichiometric amounts of La(NO₃)₃, Co(NO₃)₂, and Sb tartrate together with citric acid with a metal/citrate molar ratio of 1:2 (1.     

Zur Kristallchemie der Blei-Lanthanoid-Oxoaluminate. Zur Kenntnis von Pb2HoAl3O8 und Pb2LuAl3O8

Crystal Chemistry of the Lead Lanthanide Oxoaluminates. On Pb₂HoAl₃O₈ and Pb₂LuAl₃O₈ . Single crystals of (I) Pb₂HoAl₃O₈ and (II) Pb₂LuAl₃O₈ were prepared by flux technique and investigated by X-ray methods. It crystallizes with cubic symmetry, space group O–P4₂/n 3 2/m, (I): a = 9.4164(13) Å, (II): a = 9.3486(8) Å, Z = 4. The new structure type shows AlO₄ tetrahedra, LnO₈ hexagonal bipyramids and one sided coordinated Pb²⁺ within heterocubane units. The crystal chemical relationships to other lead oxides containing heterocubane Pb₄O₄ units are discussed.     

ChemInform Abstract: Isomorphous Substitution of Rare‐Earth Elements in Lacunary Apatite Pb8Na2(PO4)6.

Pb_8‐xLn_xNa₂(PO₄)₆ (x = 0—2.0; Ln: Y, La, Pr—Ho, Tm—Yb) with void structural channels are prepared by solid state reaction of PbO, Na₂CO₃, (NH₄)₂HPO₄, and Ln oxides (Al₂O₃ crucible, 800 °C, 2—10 d).     

Synthesis and Properties of Rb6Mn2O6

Rb₆Mn₂O₆ was prepared via the azide/nitrate route. Stoichiometric mixtures of the precursors (Mn₃O₄, RbN₃ and RbNO₃) were heated in a special regime up to 500 °C and annealed at this temperature for 75 h in silver crucibles. Single crystals have been grown by annealing a mixture with a slight excess of rubidium components at 450 °C for 500 h. According to the single crystal structure analysis, Rb₆Mn₂O₆ is isotypic to K₆Mn₂O₆, and crystallizes in the monoclinic space group P2₁/c with a = 6.924(1) Å, b = 11.765(2) Å, c = 7.066(1) Å, β = 99.21(3)°, 2296 independent reflections, R₁ = 5.23 % (all data). Manganese is tetrahedrally coordinated and two tetrahedra are linked by sharing a common edge, forming a dimer [Mn₂O₆]⁶⁻. The magnetic behavior has been investigated.     

From β-Na2B6O10 to Na3AlB8O15 and Na3Al2B7O15: Structural Tuning of Anionic-Group Architectures by Substitution of [BO4] by [AlO4] Covalent Tetrahedra

Two new sodium aluminum borates, Na₃AlB₈O₁₅ and Na₃Al₂B₇O₁₅, have been successfully synthesized by the high-temperature solution method. They crystallize in the different space groups, P2₁/c and P2/c, respectively. The B−O configurations of β-Na₂B₆O₁₀, Na₃AlB₈O₁₅ and Na₃Al₂B₇O₁₅ are compared to feature complicated different dimensional open-framework structures caused by the substitution of [BO₄] by [AlO₄] covalent tetrahedra. Moreover, the experimental results indicate that Na₃AlB₈O₁₅ and Na₃Al₂B₇O₁₅ have short ultraviolet (UV) cutoff edges (<187 nm). The first-principles calculations show that Na₃AlB₈O₁₅ and Na₃Al₂B₇O₁₅ have moderate birefringence (0.075 and 0.041@1064 nm, respectively).     

ChemInform Abstract: Synthesis,Structural Characterization and Optical Properties of a New Cesium Aluminum Borate,Cs2Al2B2O7.

The new title compound is prepared by solid state reaction of Cs₂CO₃, Al₂O₃, and H₃BO₃ (1000 °C).     

ChemInform Abstract: Density Functional Theory Calculations of UO2 Oxidation: Evolution of UO2‐x,U4O9‐y,U3O7, and U3O8.

DFT calculations of UO₂ oxidation indicate stable compounds U₄O_8.889, U₃O₇, and U₃O_7.333, which are based on ordering of split quad‐interstitial clusters.     

Preparation and Crystal Structure of Rare Earth Rhenates: the Series Ln5Re2O12 with Ln = Y,Gd–Lu,and the Praseodymium Rhenates Pr3ReO8, Pr3Re2O10, and Pr4Re2O11

The crystal structure of the known compounds Ln₅Re₂O₁₂ (Ln = Y, Gd, Dy–Lu) and the new isotypic terbium rhenate Tb₅Re₂O₁₂ was determined from X‐ray data of a twinned crystal of Ho₅Re₂O₁₂: B2/m, a = 1236.5(4) pm, b = 748.2(2) pm, c = 563.8(1) pm, γ = 107.73(3)°, Z = 2, R = 0.034 for 379 structure factors and 37 variable parameters. The rhenium atoms (oxidation number +4.5) have octahedral oxygen coordination. These ReO₆ octahedra share edges, thus forming infinite strings with alternating short and long Re–Re distances: 243.6(2) and 320.1(2) pm. Of the three holmium positions two are surrounded by seven oxygen atoms and the third one has octahedral oxygen coordination. The crystal structure of Pr₃ReO₈ was refined from single‐crystal X‐ray data: P2₁/a, a = 1498.0(2) pm, b = 749.09(8) pm, c = 610.48(9) pm, γ = 110.39(1)°, R = 0.017 for 2082 F values and 110 variable parameters. It is isotypic with a structure first determined for Sm₃ReO₈. The new compounds Pr₃Re₂O₁₀ and Pr₄Re₂O₁₁ were prepared by reaction of elemental praseodymium with the metaperrhenate Pr(ReO₄)₃. They were characterized through their X‐ray powder diagrams. Pr₃Re₂O₁₀ was found to be monoclinic: a = 778.47(9) pm, b = 773.62(9) pm, c = 706.10(8) pm, β = 114.77(1)°. It is isotypic with La₃Os₂O₁₀ and La₃Re₂O₁₀. Pr₄Re₂O₁₁ crystallizes with Nd₄Re₂O₁₁ type structure with the tetragonal lattice constants a = 1272.49(3) pm, c = 562.29(2) pm. The compounds Nd₄Re₂O₁₁ and Sm₄Re₂O₁₁ are confirmed. The magnetic properties of Ho₅Re₂O₁₂, Tb₅Re₂O₁₂, Pr₃Re₂O₁₀, Pr₄Re₂O₁₁, Nd₄Re₂O₁₁, and Sm₄Re₂O₁₁ were investigated with a Faraday balance. None of these compounds shows magnetic order above 200 K.     

Ein Beitrag über CuPrMo2O8 und CuTbMo2O8

A Contribution on CuPrMo₂O₈ and CuTbMo₂O₈ Single crystals of (I): CuPrMo₂O₈ and (II): CuTbMo₂O₈ were prepared by solid state reactions in closed copper tubes. They crystallize with orthorhombic symmetry, space group D-Pbca, (I): a = 10.4114, b = 9.8917, c = 14.8287 Å, (II): a = 10.2243, b = 9.7385, c = 14.6000, Z = 8. Both compounds are isotypic to CuYMo₂O₈, showing isolated MoO₄ tetrahedra, square antiprismatic coordination of Ln³⁺ and Cu⁺ besides one edge of an O^2? triangle. Calculations of the coulombterm of lattice energy support the oxidation state Cu²⁺ in combination with mixed valences of Mo⁶⁺ and Mo⁵⁺ on the molybdenum point positions.     

Eu3+ und Eu2+ in Oxometallaten der Zusammensetzung MBeLn2O5: SrBeEu2O5 und EuBeNd2O5

Eu³⁺ and Eu²⁺ in Oxides of the Composition MBeLn₂O₅: SrBeEu₂O₅ and EuBeNd₂O₅ Single crystals of (I): SrBeEu₂O₅ and (II): EuBeNd₂O₅ were prepared by CO₂-LASER (I) in air and plasma torch (II) technique in H₂ atmosphere. X-ray investigations led to orthorhombic symmetry, space group D-Pnma; (I): a = 9.488, b = 7.156, c = 6.495 Å; (II): a = 9.534, b = 7.225, c = 6.544 Å, Z = 4. Sr²⁺ and Eu³⁺ as well as Eu²⁺ and Nd³⁺ are in statistical distribution within a Kagomé framework. Both compounds are discussed with respect to the monoclinic form of MBeLn₂O₅.     

PdAs2O6, das erste paramagnetische Palladiumoxid

PdAs₂O₆, the First Paramagnetic Palladium Oxide Ssolid state reaction of palladium(II) oxide (PdO) and arsenic(V) oxide (As₂O₅) yielded an auburn colored microcrystalline powder of palladium(II) metaarsenate(V), PdAs₂O₆. The crystal structure of the compound belongs to the PbSb₂O₆ structure type, (no. 162), a = 4.8196(0) Å, c = 4.6646(1) Å, V = 93.84(0) ų and Z = 1. The structure consists of layers of edge sharing AsO₆ octahedra and PdO₆ octahedra connecting them. This is one of the rare structures with divalent palladium in octahedral coordination by oxygen. The compound is paramagnetic and shows antiferromagnetic ordering at about 150 K, which is 5 times higher than that of the isotypic NiAs₂O₆ compound.     

ChemInform Abstract: Tetrayttrium Difluoride Disilicate Orthosilicate,Y4F2[Si2O7][SiO4].

Colorless lath-shaped single crystals of the title compound are obtained from a melt of Y₂O₃, YF₃, and SiO₂ (2:5:3 molar ratio) using CsCl as a flux (evacuated silica tube, 973 K, 9 d, 10 K/h cooling rate).     

Significantly Improved Colossal Dielectric Properties and Maxwell—Wagner Relaxation of TiO2—Rich Na1/2Y1/2Cu3Ti4+xO12 Ceramics

In this work, the colossal dielectric properties and Maxwell—Wagner relaxation of TiO₂–rich Na_1/2Y_1/2Cu₃Ti_4+xO₁₂ (x = 0–0.2) ceramics prepared by a solid-state reaction method are investigated. A single phase of Na_1/2Y_1/2Cu₃Ti₄O₁₂ is achieved without the detection of any impurity phase. The highly dense microstructure is obtained, and the mean grain size is significantly reduced by a factor of 10 by increasing Ti molar ratio, resulting in an increased grain boundary density and hence grain boundary resistance (R_gb). The colossal permittivities of ε′ ~ 0.7–1.4 × 10⁴ with slightly dependent on frequency in the frequency range of 10²–10⁶ Hz are obtained in the TiO₂–rich Na_1/2Y_1/2Cu₃Ti_4+xO₁₂ ceramics, while the dielectric loss tangent is reduced to tanδ ~ 0.016–0.020 at 1 kHz due to the increased R_gb. The semiconducting grain resistance (R_g) of the Na_1/2Y_1/2Cu₃Ti_4+xO₁₂ ceramics increases with increasing x, corresponding to the decrease in Cu⁺/Cu²⁺ ratio. The nonlinear electrical properties of the TiO₂–rich Na_1/2Y_1/2Cu₃Ti_4+xO₁₂ ceramics can also be improved. The colossal dielectric and nonlinear electrical properties of the TiO₂–rich Na_1/2Y_1/2Cu₃Ti_4+xO₁₂ ceramics are explained by the Maxwell–Wagner relaxation model based on the formation of the Schottky barrier at the grain boundary.     

Syntheses,Structures, Magnetic Properties,and NIR Emission Properties of a Series of Novel 1, 2, 4, 5‐Cyclohexanetetracarboxylate‐bridged Lanthanide Complexes with 3D Framework Structures

Solvothermal combination of trivalent lanthanide metal precursors with 1, 2, 4, 5‐cyclohexanetetracarboxylic acid (L) ligand has afforded the preparation of a family of eight new coordination polymers [Ln₄(L)₃(H₂O)₁₀] · 7H₂O (Ln = Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) ( 1 – 8 ). Structural analyses reveal that the 1, 2, 4, 5‐cyclohexanetetracarboxylic acid ligand with e,a,a,e (L^I) conformation displays a μ₄‐(κ³O, O, O⁵)(κ²O²,O²)(κ²O⁴,O⁴)‐bridging mode to generate 3D frameworks of complexes 1 – 8 and the α‐Po topology with the short Schläfli symbol {4¹².6³} could be observed in complexes 1 – 8 . The near‐infrared luminescence properties were studied, and the results have shown that the Ho^III, Er^III, and Yb^III complexes emit typical near‐infrared luminescence in the solid‐state. Variable‐temperature magnetic susceptibility measurements of complexes 2 – 7 have shown that complex 2 (Gd) shows the ferromagnetic coupling between magnetic centers, whereas the complexes 3 – 7 show the antiferromagnetic coupling between magnetic centers. Additionally, the thermogravimetric analyses were discussed.     

ChemInform Abstract: Two‐Dimensional Phosphorus Oxides as Energy and Information Materials.

The lowest‐energy structures of two‐dimensional P_nO (n = 8, 6, 4, 2), P₄O₄, and P₂O₃ are predicted by a global optimization method based on the particle swarm optimization technique.