Completing the Series: New Coordination Networks of Composition 3∞[RE2(ADC)3(H2O)6]·2H2O with RE = Pr,Nd, Sm,Eu, Tb,Dy, Ho,Er, Y and ADC2– = Acetylenedicarboxylate (–O2C–C≡C–CO2–)

The crystal structures of ³_∞[RE₂(ADC)₃(H₂O)₆] · 2H₂O (RE = Pr, Nd, Sm, Eu, Tb, Dy) were solved and refined from X‐ray single crystal data. They crystallize in a structure type already known for RE = La, Ce and Gd (P1 , no. 2, Z = 2), which is characterized by REO₉ polyhedra forming dimeric units being the nodes of a 3D framework structure linked by ADC^2– anions (^–O₂C–C≡C–CO₂^– = acetylenedicarboxylate). From synchrotron powder diffraction data it was shown that isostructural coordination networks are formed for RE = Ho, Er, Y, whereas for RE = Tm, Yb, Lu a new structure type crystallizing in a highly complex crystal structure with a large orthorhombic unit cell is found. All compounds are obtained by slow evaporation of an aqueous solution containing RE(OAc)₃ · xH₂O and acetylenedicarboxylic acid (H₂ADC). The coordination networks of composition ³_∞[RE₂(ADC)₃(H₂O)₆] · 2H₂O were thoroughly investigated by thermal analysis and for RE = Eu, Tb, a strong red and green photoluminescence was observed and investigated by means of UV/Vis spectroscopy.     

Fluoroplatinate(IV) der Lanthaniden LnF[PtF6]. (Ln = Pr,Sm, Gd,Tb, Dy,Ho, Er)

Fluoroplatinates(IV) of the Lanthanides LnF[PtF₆] (Ln = Pr, Sm, Gd, Tb, Dy, Ho, Er) For the first time fluorides LnF[PtF₆] (Ln = Pr, Sm, Gd, Tb, Dy, Ho, Er), all yellow have been obtained. From single crystal data they crystallize monoclinic, space group P2₁/n?C (No. 14), Z = 4, Pr: a = 1 125.77(19) pm, b = 559.04(7) pm, c = 910.27(17) pm, β = 107.29(1)°; Sm: a = 1 114.63(31) pm, b = 552.70(12) pm, c = 898.02(20) pm, β = 107.24(2)°; Gd: a = 1 112.12(15) pm, b = 551.22(7) pm, c = 891.99(11) pm, β = 107.09(1)°; Tb (Powder data): a = 1 108.88(20) pm, b = 552.71(9) pm, c = 889.56(16) pm, β = 107.30(1)°; Dy: a = 1 100.28(23) pm, b = 547.77(8) pm, c = 882.41(13) pm, β = 107.32(1); Ho: a = 1 099.11(16) pm, b = 546.16(7) pm, c = 879.45(15) pm, β = 107.34(1)°; Er: a = 1 095.10(16) pm, b = 544.82(10) pm, c = 874.85(14) pm, β = 107.37(1)°.     

Synthesis and Crystal Structure of (2,4-C_7H_(11))_3Ln(Ln=Dy,Er)

Ernst etal[1 ] reported the synthesis and crystal structure of( 2 ,4 -C7H1 1 ) 3Nd in1 982and then,the crystal structure of( 2 ,4 -C7H1 1 ) 3Gd[2 ] was also determined.In the rareearth triscyclopentadienyl compounds,the Dy complex s structure is not in agreementwith the lanthanide contraction regularity,called“gadolinium break phenomenon”[3] .Inorder to study the reality of this phenomenon,we have determined the crystal structuresof( 2 ,4 -C7H1 1 ) 3Dy( 1 ) and( 2 ,4 -C7H1 1 ) 3Er( 2 ) …     

On the Perovskites Ba2LnSbO6 (Ln = Nd,Sm, Eu,Gd, Tb,Dy, Ho,Er, Yb)

Polycrystalline Ba₂LnSbO₆ (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb) are cubic, perovskite-type compounds, space group Fm3m (No. 225), Z = 4, with a values from a = 8.544(2) Å for Ba₂NdSbO₆ to a = 8.368(1) Å for Ba₂YbSbO₆. X-ray diffraction data for all the compounds and the results of magnetic measurements for two of them are given.     

Ternary Rare Earth Rhodium Antimonides Ln6Rh30Sb19 with Ln = La–Nd,Sm, and Eu

The six title compounds were prepared by annealing cold‐pressed pellets consisting of stoichiometric mixtures of binary rare earth and rhodium antimonides with additional elemental rhodium in evacuated silica tubes. Their crystal structure was determined from four‐circle X‐ray diffractometer data of a Eu₆Rh₃₀Sb₁₉ single crystal, which was isolated from an arc‐melted sample annealed just below the melting temperature in a high‐frequency furnace. It is hexagonal: P6₃/m, a = 1693.2(2) pm, c = 408.11(4) pm, Z = 1. The least‐squares refinement resulted in a residual of R = 0.034 for 1259 structure factors and 62 variable parameters. The structure shows some disorder around the 6₃ axis but otherwise is very similar to the structures of Sc₆Co₃₀Si₁₉ and Yb₆Co₃₀P₁₉, but different from that of U₆Co₃₀Si₁₉. The plot of the cell volumes of the new series Ln₆Rh₃₀Sb₁₉ indicates the europium atoms in Eu₆Rh₃₀Sb₁₉ to be at least partially divalent.     

Syntheses,Crystal Structures,and Optical and Magnetic Properties of Some CsLnCoQ3 Compounds (Ln = Tm and Yb,Q = S; Ln = Ho and Yb,Q = Se)

The four new compounds CsTmCoS₃, CsYbCoS₃, CsHoCoSe₃, and CsYbCoSe₃ have been synthesized at 1123 K. These black‐colored isostructural compounds crystallize in the KZrCuS₃ structure type with four formula units in space group Cmcm of the orthorhombic system. The structure of these compounds is composed of layers separated by Cs atoms. Because there are no Q–Q bonds, the formal oxidation states of Cs/Ln/Co/Q are 1+/3+/2+/2?, respectively. CsHoCoSe₃ shows paramagnetic behavior with μ_eff = 11.9(1) μ_B, whereas CsYbCoS₃ displays an antiferromagnetic‐like transition at ～2.7 K with μ_eff = 5.85(1) μ_B. Both CsYbCoS₃ and CsYbCoSe₃ exhibit optical band gaps in the near infrared region and broad absorption bands at lower energies.     

Neue Verbindungen zum BaNiNd2O5-Typ: BaNiLn 2O5 (Ln=Sm,Gd, Ho,Er, Tm)

Five new compounds of the BaNiNd₂O₅-type with the rare earth elements Sm, Gd, Ho, Er, Tm are prepared and examined by X-ray single crystal technique. The atomic parameters are refined by least-square methods. The crystal chemical differences in the surrounding of rare earth ions in BaMLn ₂O₅-compounds (M=Pt, Pd, Cu, Ni) are discussed.

     

New Ternary Phosphides Ln25Ni49P33 (Ln = Ce,Pr, Nd,Sm, Gd,Tb, Dy,Ho, Er)

New ternary phosphides Ln₂₅Ni₄₉P₃₃ (Ln = Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er) have been synthesized by arc melting of pure components. Crystal structure has been determined for Sm₂₅Ni₄₉P₃₃ using X‐ray powder diffraction data and the Rietvelt method: P6m2, a = 22.096(4), c = 3.8734(9) Å, R = 0.096. Crystal structure of Sm₂₅Ni₄₉P₃₃ is of a new type and belongs to large family of ternary compounds with trigonal‐prismatic coordination of the smallest size atoms and metal to nonmetal ratio equal or close to 2 : 1. It is a member of homologous subseries of the compounds with unit cell contents described by general chemical formula R M X . Lattice parameters of the isotypic compounds Ln₂₅Ni₄₉P₃₃ have been refined using X‐ray powder diffraction data.     

Crystal structure variations in the series SrLnCuS3 (Ln = La,Pr, Sm,Gd, Er and Lu)

The crystal structures of the complex sulfides SrLnCuS₃ (Ln = Sm, Gd, Er and Lu) have been determined and refined using powder X‐ray diffraction. The crystals are found to be orthorhombic, with the structure type changing consecutively in the order BaLaCuS₃ → Eu₂CuS₃ → KZrCuS₃ as the Ln³⁺ ionic radius decreases in the order La/Pr → Sm/Gd → Er/Lu. Variations of the structure parameters along the series of compounds studied are analyzed, and an effect caused by crystallochemical contraction on the stabilization of the respective structure types is demonstrated.     

Synthesis and characterization of ethylthioethylcyclopentadienyl organolanthanide complexes: CpLnCl (Ln=Gd,Dy), Cp2LnCpTh (Ln=Yb,Sm, Dy,Y) and CpThErCl2·2THF

Six new ethylthioethylcyclopentadienyl containing organolanthanide complexes CpLnCl [Ln=Gd (1), Dy (2)] and Cp₂LnCp^Th [Cp=C₅H₅, Ln=Yb (3), Sm (4), Dy (5), Y (6)] were synthesized by the reaction of ethylthioethyl‐cyclopentadienyl (Cp^Th) sodium salt with LnCl₃ or Cp₂LnCl in THF. Complexes 1–6 were characterized by elemental analyses, infrared and mass spectroscopies. The molecular structures of complexes 1–3 were also determined by the X‐ray single crystal diffraction. The results show that the side‐chain sulfur atom on the ethylthioethylcyclopentadienyl ring can form intramolecular chelating coordination to the central lanthanide ion, improving the stability of organolanthanide complexes and reducing the number of coordinated THF molecules.     

Synthesis and structure determination of seven ternary bismuthides: crystal chemistry of the RELi3Bi2 family (RE = La–Nd,Sm, Gd,and Tb)

Zintl phases are renowned for their diverse crystal structures with rich structural chemistry and have recently exhibited some remarkable heat‐ and charge‐transport properties. The ternary bismuthides RELi₃Bi₂ (RE = La–Nd, Sm, Gd, and Tb) (namely, lanthanum trilithium dibismuthide, LaLi₃Bi₂, cerium trilithium dibismuthide, CeLi₃Bi₂, praseodymium trilithium dibismuthide, PrLi₃Bi₂, neodymium trilithium dibismuthide, NdLi₃Bi₂, samarium trilithium dibismuthide, SmLi₃Bi₂, gadolinium trilithium dibismuthide, GdLi₃Bi₂, and terbium trilithium dibismuthide, TbLi₃Bi₂) were synthesized by high‐temperature reactions of the elements in sealed Nb ampoules. Single‐crystal X‐ray diffraction analysis shows that all seven compounds are isostructural and crystallize in the LaLi₃Sb₂ type structure in the trigonal space group Pm1 (Pearson symbol hP6). The unit‐cell volumes decrease monotonically on moving from the La to the Tb compound, owing to the lanthanide contraction. The structure features a rare‐earth metal atom and one Li atom in a nearly perfect octahedral coordination by six Bi atoms. The second crystallographically unique Li atom is surrounded by four Bi atoms in a slightly distorted tetrahedral geometry. The atomic arrangements are best described as layered structures consisting of two‐dimensional layers of fused LiBi₄ tetrahedra and LiBi₆ octahedra, separated by rare‐earth metal cations. As such, these compounds are expected to be valance‐precise semiconductors, whose formulae can be represented as (RE³⁺)(Li¹⁺)₃(Bi³⁻)₂.     

Hydrothermal Synthesis of Rare Earth Iodates from the Corresponding Periodates: II1). Synthesis and Structures of Ln(IO3)3 (Ln = Pr,Nd, Sm,Eu, Gd,Tb, Ho,Er) and Ln(IO3)3 · 2H2O (Ln = Eu,Gd, Dy,Er, Tm,Yb)

Single crystals of lanthanide iodates have been quickly grown by decomposition of the corresponding periodates under hydrothermal conditions. Single crystal X‐ray diffraction showed that two structure types form with the elements from Pr‐Yb, an anhydrous form for Pr, Nd, Sm, Eu, Gd, Tb, Ho, Er and a dihydrate for Eu, Gd, Dy, Er, Tm, Yb. A detailed structure study is presented for one representative of each of these types, along with structure type and lattice parameters for the other materials. Tb(IO₃)₃: Space group P2₁/c, Z = 4, lattice dimensions at 120 K: a = 7.102(1), b = 8.468(1), c = 13.355(2)Å, β = 99.67(1)°; R1 = 0.034. Yb(IO₃)₃ · 2H₂O: Space group P1¯, Z = 2, lattice dimensions at 120 K: a = 7.013(1), b = 7.370(1), c = 10.458(2)Å, α = 95.250(5), β = 105.096(5), γ = 109.910(10)°; R1 = 0.024.     

Orthorhombic HP‐REOF (RE = Pr,Nd, Sm – Gd) – High‐Pressure Syntheses and Single‐Crystal Structures (RE = Nd,Sm, Eu)

High‐pressure modifications of the rare earth oxide fluorides REOF (RE = Pr, Nd, Sm – Gd) were successfully synthesized under conditions of 11 GPa and 1200 °C applying the multianvil high‐pressure/high‐temperature technique. Single crystals of HP‐REOF (RE = Nd, Sm, Eu) were obtained making it possible to analyze the products by means of single‐crystal X‐ray diffraction. The compounds HP‐REOF (RE = Nd, Sm, Eu) crystallize in the orthorhombic α‐PbCl₂‐type structure (space group Pnma, No. 62, Z = 4) with the parameters a = 632.45(3), b = 381.87(2), c = 699.21(3) pm, V = 0.16887(2) nm³, R₁ = 0.0156, and wR₂ = 0.0382 for HP‐NdOF, a = 624.38(3), b = 376.87(2), c = 689.53(4) pm, V = 0.16225(2) nm³, R₁ = 0.0141, and wR₂ = 0.0323 for HP‐SmOF, and a = 620.02(4), b = 374.24(3), c = 686.82(5) pm, V = 0.15937(2) nm³, R₁ = 0.0177, and wR₂ = 0.0288 for HP‐EuOF. Calculations of the bond valence sums clearly showed that the oxygen atoms occupy the tetrahedrally coordinated position, whereas the fluorine atoms are fivefold coordinated in form of distorted square‐pyramids. The crystal structures and properties of HP‐REOF (RE = Nd, Sm, Eu) are discussed and compared to the isostructural phases and the normal‐pressure modifications of REOF (RE = Nd, Sm, Eu). Furthermore, results of investigations by EDX and Raman measurements including quantum mechanical calculations are presented.     

Reduction specifics of rare-earth orthovanadates (REE = La,Nd, Sm,Dy, Ho,Er, Tm,Yb, and Lu)

The reduction specifics of REE orthovanadates LnVO₄ (Ln = La, Nd, Sm, Dy, Ho, Er, Tm, Yb, and Lu) have been studied using the temperature-programmed reduction (TPR) method. Hydrogen and carbon monoxide were chosen as reducing agents. The reduction temperature is found to depend both on the REE and the reducing agent. REE orthovanadates are reduced in the range 1033–1153 K not forming phases that contain vanadium in intermediate oxidation states. In CO, the reduction temperature is found to be higher than in H₂ for all orthovanadates. TPR data have been used to calculate the activation energies of reduction of REE orthovanadates using the Kissinger equation. The effective activation energies of reduction depend on the REE and the reducing agent and are in the range 41–147 kJ/mol.     

BaLn2Se4 (Ln = Er,Tm and Yb)

The compounds BaLn₂Se₄ (Ln = rare‐earth metal = lanthanide = Er, Tm and Yb), namely barium di(erbium/thulium/ytterbium) tetraselenide, crystallize in the orthorhombic space group Pnma in the CaFe₂O₄ structure type. In this structure type, all atoms possess m symmetry. The Ln atoms are octahedrally coordinated by six Se atoms. A three‐dimensional channel structure is formed by the corner‐ and edge‐sharing of these LnSe₆ octahedra. The Ba atoms are coordinated to eight Se atoms in a bicapped trigonal–prismatic arrangement, and they occupy the channels of the three‐dimensional framework.     

Synthesen und Kristallstrukturen von neuen Alkalimetall‐Selten‐Erd‐Telluriden der Zusammensetzungen KLnTe2 (Ln = La,Pr, Nd,Gd), RbLnTe2 (Ln = Ce,Nd) und CsLnTe2 (Ln = Nd)

Syntheses and Crystal Structures of New Alkali Metal Rare‐Earth Tellurides of the Compositions KLnTe₂ (Ln = La, Pr, Nd, Gd), RbLnTe₂ (Ln = Ce, Nd) and CsLnTe₂ (Ln = Nd) Of the compounds ALnQ₂ (A = Na, K, Rb, Cs; Ln = rare earth‐metal; Q = S, Se, Te) the crystal structures of the new tellurides KLaTe₂, KPrTe₂, KNdTe₂, KGdTe₂, RbCeTe₂, RbNdTe₂, and CsNdTe₂ were determined by single‐crystal X‐ray analyses. They all crystallize in the α‐NaFeO₂ type with space group R3¯m and three formula units in the unit cell. The lattice parameters are: KLaTe₂: a = 466.63(3) pm, c = 2441.1(3) pm; KPrTe₂: a = 459.73(2) pm, c = 2439.8(1) pm; KNdTe₂: a = 457.83(3) pm, c = 2443.9(2) pm; KGdTe₂: a = 449.71(2) pm, c = 2443.3(1) pm; RbCeTe₂: a = 465.18(2) pm, c = 2533.6(2) pm; RbNdTe₂: a = 459.80(3) pm, c = 2536.5(2) pm, and CsNdTe₂: a = 461.42(3) pm, c = 2553.9(3) pm. Characteristics of the α‐NaFeO₂ structure type as an ordered substitutional variant of the rock‐salt (NaCl) type are layers of corner‐sharing [(A⁺/Ln³⁺)(Te^2—)₆] octahedra with a layerwise alternating occupation by the cations A⁺ and Ln³⁺.     

Tetrafluoroaurate(III) der Lanthaniden M2F[AuF4]5 (M = Tb,Dy, Ho,Er)

Tetrafluoroaurates(III) of Lanthanoides M₂F[AuF₄]₅ (M = Tb, Dy, Ho, Er) Tetrafluoroaurates(III) M₂F[AuF₄]₅ with M = Tb, Dy, Ho, Er, all yellow, have been obtained. From single crystal data they crystallize triclinic, space group P1 -C¹_i (No. 2) with Tb: a = 1 194,34(7) pm, b = 798,46(6) pm, c = 902,02(7) pm, α = 89,033(7)°, β = 88,990(6)°, γ = 89,006(7)°; Dy: a = 1 191,66(9) pm, b = 796,33(8) pm, c = 899,65(9) pm, α = 88,956(8)°, β = 89,056(8)°, γ = 88,972(8)°; Ho: a = 1 189,06(10) pm, b = 795,46(6) pm, c = 896,81(7) pm, α = 88,912(8)°, β = 89,101(7)°, γ = 88,873(8)°; Er: a = 1 185,20(40), b = 793,98(14), c = 893,83(20), α = 88,751(23)°, β = 89,187(26)°, γ = 88,884(9)°     

Preparation and crystal structure of the Isotypic Carbides Ln4Ni2C5 (Ln = Er,Tm, Yb and Lu)

The title compounds were prepared from the elemental components in a lithium flux. Their crystal structure was determined for the ytterbium compound from single-crystal X-ray data. It is orthorhombic, Pmm2, a = 352.88(6) pm, b = 1 143.0(3) pm, c = 366.16(6) pm, Z = 1, R = 0.020 for 1 261 structure factors and 29 variable parameters. The structure may be viewed as an intergrowth of slabs consisting of the CeNiC₂ and the ScC (NaCl type) structures. It thus contains C₂ pairs with a C? C distance of 138(1) pm and isolated carbon atoms. Together with the nickel atoms the C₂ pairs form one-dimensionally infinite building elements [Ni₂C₄]_n. The fifth carbon atom is octahedrally coordinated by ytterbium atoms. Accordingly the compound may be rationalized to a first approximation with the formula (Yb³⁺)₄[Ni₂C₄^8?]C^4?. Yb₄Ni₂C₅ shows Curie-Weiss behaviour with a magnetic moment of μ_exp = 4.44 μ_B per ytterbium atom in good agreement with the theoretical moment of μ_eff = 4.53 μ_B for Yb³⁺.     

Crystal Structure of the RE2PbS4 (RE = Y,Dy, Ho,Er, and Tm) Compounds and a Comparison with the Crystal Structures of other Rare Earth Lead Chalcogenides

The crystal structure of the RE₂PbS₄ (RE = Y, Dy, Ho, Er and Tm) compounds (space group Cmc2₁, Pearson symbol oC112, a = 0.79301(3) nm, b = 2.86966(9) nm, c = 1.20511(5) nm, R_Bragg = 0.0979 for Y₂PbS₄; a = 0.79484(8) nm, b = 2.8721(3) nm, c = 1.2039(1) nm, for Dy₂PbS₄; a = 0.79081(2) nm, b = 2.86222(7) nm, c = 1.20220(4) nm, R_Bragg = 0.0859 for Ho₂PbS₄; a = 0.7863(2) nm, b = 2.8525(5) nm, c = 1.1995(2) nm, R1 = 0.0482 for Er₂PbS₄ and a = 0.78419(3) nm, b = 2.84184(9) nm, c = 1.19655(4) nm, R_Bragg = 0.0893 for Tm₂PbS₄) was investigated by means of X‐ray single crystal and powder diffraction. Each RE atoms is octahedrally coordinated by six S atoms. Each Pb atoms is surrounded by seven S atoms to form a mono‐capped trigonal prism.