Structure and properties of Ce<Subscript>3</Subscript>Pd<Subscript>3</Subscript>Bi<Subscript>4</Subscript>, CePdBi,and CePd<Subscript>2</Subscript>Zn<Subscript>3</Subscript>

The intermetallic cerium compounds Ce₃-Pd₃Bi₄, CePdBi, and CePd₂Zn₃ were synthesized from the elements in sealed tantalum ampoules in an induction furnace. The compounds were characterized by X-ray powder and single crystal diffraction: CeCo₃B₂ type (ordered version of CaCu₅), P6/mmm, a = 538.4(4), c = 427.7(4) pm, wR2 = 0.0540, 115 F ² values, 9 variables for CePd₂Zn₃ and Y₃Au₃Sb₄ type, I \({\bar 4}\)3d, a = 1005.2(2) pm, w R2 = 0.0402, 264 F ² values, 9 variables for Ce₃Pd₃Bi₄, and MgAgAs type, a = 681.8(1) pm for CePdBi. The bismuthide structures are build up from three-dimensional networks of corner-sharing PdBi₄ tetrahedra with Pd–Bi distances of 281 (Ce₃Pd₃Bi₄) and 296?pm (CePdBi), respectively. The cerium atoms are located in larger voids of coordination number 12 (Ce₃Pd₃Bi₄) and 10 (CePdBi). In CePd₂Zn₃ the cerium atoms fill larger channels within the three-dimensional [Pd₂Zn₃] network with 18 (6 Pd + 12 Zn) nearest neighbors. The three compounds contain stable trivalent cerium with experimental magnetic moments of μ_eff = 2.70(2), 2.48(1), and 2.49(1) μ_B/Ce atom for CePd₂Zn₃, Ce₃Pd₃Bi₄, and CePdBi, respectively. Susceptibility and specific heat data gave no hint for magnetic ordering down to 2.1?K.     

La3Pd4Zn4 and La3Pt4Zn4 with a different coloring of the Gd3Cu4Ge4-type structure

Abstract  

The intermetallic zinc compounds La₃Pd₄Zn₄ and La₃Pt₄Zn₄ were synthesized by induction melting of the elements in sealed tantalum tubes. The structures were refined from X-ray single-crystal diffractometer data: Gd₃Cu₄Ge₄ type, Immm, a = 1,440.7(5), b = 743.6(2), c = 419.5(2) pm, wR ₂ = 0.0511, 353 F ² for La₃Pd₄Zn₄; and a = 1,439.9(2), b = 748.1(1), c = 415.66(6) pm, wR ₂ = 0.0558, 471 F ² for La₃Pt₄Zn₄ with 23 variables per refinement. The palladium (platinum) and zinc atoms build up a three-dimensional polyanionic [Pd₄Zn₄] (260–281 pm Pd–Zn) and [Pt₄Zn₄] (260–279 pm Pt–Zn) network in which the lanthanum atoms fill cavities of CN 14 (6 Pd/Pt + 8 Zn for La1) and CN 12 (6 Pd/Pt + 6 Zn for La2), respectively. The copper position of the Gd₃Cu₄Ge₄ type is occupied by zinc and the two crystallographically independent germanium sites by palladium (platinum), a new coloring pattern for this structure type. Within the [Pd₄Zn₄] and [Pt₄Zn₄] the Pd2 and Pt2 atoms form Pd2–Pd2 (291 pm) and Pt2–Pt2 (296 pm) dumbbells. The structures of La₃Pd₄Zn₄ and La₃Pt₄Zn₄ are discussed with respect to the prototype Gd₃Cu₄Ge₄ and the Zintl phase Sr₃Li₄Sb₄. Temperature-dependent magnetic susceptibility measurements indicate diamagnetism for La₃Pt₄Zn₄ and Pauli paramagnetism for La₃Pd₄Zn₄.     

La6Pd13Cd4 and Ce6Pd13Cd4 with palladium-centred rare earth octahedra: synthesis, structure, and chemical bonding

Abstract  

The palladium-rich cadmium compounds La₆Pd₁₃Cd₄ and Ce₆Pd₁₃Cd₄ were synthesized by induction melting the elements in sealed tantalum ampoules and subsequent annealing. They were characterized by X-ray powder and single-crystal diffraction: Na₁₆Ba₆N type, Im[`3] mIm\overline{3} m, a = 988.12(9) pm, wR2 = 0.0463, 225 F ² values, and 12 variables for La₆Pd₁₃Cd₄, and a = 982.1(2) pm, wR2 = 0.0521, 215 F ² values, and 12 variables for Ce₆Pd₁₃Cd₄. The striking structural motifs are palladium-centred La₆ and Ce₆ octahedra, which are packed in a bcc fashion. Further palladium and cadmium atoms built up three-dimensional [Pd₃Cd] networks in which the La₆Pd and Ce₆Pd octahedra are embedded. Chemical bonding analyses show that the dominant interaction occurs within the palladium-centred RE ₆ octahedra, while weaker bonding exists between them.     

Preparation and Structure of Cerium Titanates Ce2TiO5, Ce2TiO7, and Ce4Ti9O24

Compounds Ce₂TiO₅, Ce₂Ti₂O₇, and Ce₄Ti₉O₂₄ were prepared by heating appropriate mixtures of solids containing Ce⁴⁺ and Ti³⁺ or Ti which were placed in a platinum-silica-ampoule combination at T = 1250°C (3d) under vacuum. The new compounds were characterized by powder patterns. We obtained Ce₂TiO₅ which is isotypic to La₂TiO₅ and crystallizes in the Y₂TiO₅-type (space group Pnma) with a = 10.877(6) Å, b = 3.893(1) Å, c = 11.389(8) Å, Z = 4. Ce₂Ti₂O₇ is isotypic to La₂Ti₂O₇ and crystallizes in the monoclinic Ca₂Nb₂O₇ type (space group P 2₁) with a = 7.776(6) Å, b = 5.515(4) Å, c = 12.999(6) Å, β = 98.36(5), Z = 4. The compound Ce₄Ti₉O₂₄ crystallizes orthorhombic with a = 14.082(4) Å, b = 35.419(8) Å, c = 14.516(4) Å, Z = 16. The new cerium titanate Ce₄Ti₉O₂₄ is isotypic to Nd₄Ti₉O₂₄ (space group Fddd (No. 70)) which represents a novel type of structure.     

空气中合成固溶体荧光粉Ba_2(Zn,Mg)Si_2O_7∶Eu~(2+),Eu~(3+),Ce~(3+)及其发光特性

采用高温固相法在空气中合成了Ba1.97-yZn1-xMgxSi2O7∶0.03Eu,y Ce3+系列荧光粉。分别采用X-射线衍射和荧光光谱对所合成荧光粉的物相和发光性质进行了表征。在紫外光330~360 nm激发下,固溶体荧光粉Ba1.97-yZn1-xMgxSi2O7∶0.03Eu的发射光谱在350~725 nm范围内呈现多谱峰发射,360和500 nm处有强的宽带发射属于Eu2+离子的4f 65d1-4f 7跃迁,590~725 nm红光区窄带谱源于Eu3+的5D0-7FJ(J=1,2,3,4)跃迁,这表明,在空气气氛中,部分Eu3+在Ba1.97-yZn1-xMgxSi2O7基质中被还原成了Eu2+;当x=0.1时,荧光粉Ba1.97Zn0.9Mg0.1Si2O7∶0.03Eu的绿色发光最强,表明Eu3+被还原成Eu2+离子的程度最大。当共掺入Ce3+离子后,形成Ba1.97-yZn0.9Mg0.1Si2O7∶0.03Eu,y Ce3+荧光粉体系,其发光随着Ce3+离子浓度的增大由蓝绿区经白光区到达橙红区;发现名义组成为Ba1.96Zn0.9Mg0.1Si2O7∶0.03Eu,0.01Ce3+的荧光粉的色坐标为(0.323,0.311),接近理想白光,是一种有潜在应用价值的白光荧光粉。讨论了稀土离子在Ba2Zn0.9Mg0.1Si2O7基质中的能量传递与发光机理。     

Ternary Indides RE4Pd10In21 (RE = La,Ce, Pr,Nd, Sm) — Synthesis,Structure, and Physical Properties

The ternary indium compounds RE₄Pd₁₀In₂₁ (RE = La, Ce, Pr, Nd, Sm) were synthesized from the elements in glassy carbon crucibles in a high‐frequency furnace. Single crystals of Sm₄Pd₁₀In₂₁ were obtained from an indium flux. An arc‐melted precursor alloy of the starting composition ～SmPd₃In₆ was annealed with a slight excess of indium at 1200 K followed by slow cooling (5 K/h) to 870 K. All compounds were investigated by X‐ray powder diffraction and the structures were refined from single crystal diffractometer data. The RE₄Pd₁₀In₂₁ indides are isotypic with Ho₄Ni₁₀Ga₂₁, space group C2/m: a = 2314.3(2), b = 454.70(7), c = 1940.7(2) pm, β = 133.43(2)°, wR2 = 0.0681, 1678 F² values for La₄Pd₁₀In₂₁, a = 2308.2(1), b = 452.52(4), c = 1944.80(9) pm, β = 133.40(1)°, wR2 = 0.0659, 1684 F² values for Ce₄Pd₁₀In₂₁, a = 2303.8(2), b = 450.78(4), c = 1940.6(1) pm, β = 133.39(1)°, wR2 = 0.0513, 1648 F² values for Pr₄Pd₁₀In₂₁, a = 2300.2(2), b = 449.75(6), c = 1937.8(2) pm, β = 133.32(1)°, wR2 = 0.1086, 1506 F² values for Nd₄Pd₁₀In₂₁, and a = 2295.6(2), b = 447.07(4), c = 1935.7(1) pm, β = 133.16(1)°, wR2 = 0.2291, 2350 F² values for Sm₄Pd₁₀In₂₁, with 108 variables per refinement. All palladium atoms have a trigonal prismatic coordination. The strongest bonding interactions occur for the Pd—In and In—In contacts. The structures are composed of covalently bonded three‐dimensional [Pd₁₀In₂₁] networks in which the rare earth metal atoms fill distorted pentagonal channels. The crystal chemistry and chemical bonding in these indides is briefly discussed. Magnetic susceptibility measurements show diamagnetism for La₄Pd₁₀In₂₁ and Curie‐Weiss paramagnetism for Ce₄Pd₁₀In₂₁, Pr₄Pd₁₀In₂₁, and Nd₄Pd₁₀In₂₁. The neodymium compound orders antiferromagnetically at T_N = 4.5(2) K and undergoes a metamagnetic transition at a critical field of 1.5(2) T. All the RE₄Pd₁₀In₂₁ indides studied are metallic conductors.     

The Stannides YNi x Sn2 ( x = 0, 0.14, 0.21, 1) – Syntheses, Structure, and 119Sn M?ssbauer Spectroscopy

The stannides YNi _x Sn₂ (x = 0, 0.14, 0.21, 1) were prepared by arc-melting of the pure elements. They were characterized through X-ray powder and single crystal data: ZrSi₂ type, space group Cmcm, a = 438.09(6), b = 1629.6(4), c = 430.34(7) pm, wR2 = 0.0607, 386 F ² values, 14 variables for YSn₂, CeNiSi₂ type, Cmcm, a = 440.6(1), b = 1640.3(1), c = 433.0(1) pm, wR2 = 0.0632, 416 F ² values, 19 variables for YNi_0.142(7)Sn₂, a = 441.0(1), b = 1646.3(1), c = 434.6(1) pm, wR2 = 0.0491, 287 F ² values, 19 variables for YNi_0.207(7)Sn₂, and LuNiSn₂ type, space group Pnma, a = 1599.3(3), b = 440.89(5), c = 1456.9(2) pm, wR2 = 0.0375, 1538 F ² values, 74 variables for YNiSn₂. The YSn₂ structure contains Sn1–Sn1 zig-zag chains (297 pm) and planar Sn2 networks (307 pm). The stannides YNi_0.142(7)Sn₂ and YNi_0.207(7)Sn₂ are nickel filled versions of YSn₂. The nickel atoms have a distorted pyramidal tin coordination with Ni–Sn distances ranging from 220 to 239 pm. New stannide YNiSn₂ adopts the LuNiSn₂ type. The nickel and tin atoms build up a complex three-dimensional [NiSn₂] network in which the yttrium atoms fill distorted pentagonal and hexagonal channels. Within the network all nickel atoms have a distorted square pyramidal tin coordination with Ni–Sn distances ranging from 247 to 276 pm. Except the Sn4 atoms which are located in a tricapped trigonal Y₆ prism, all tin atoms have between 4 and 5 tin neighbors between 297 and 350 pm. ¹¹⁹Sn M?ssbauer spectroscopic data of YNi _x Sn₂ show a decreasing isomer shift (from 2.26 to 2.11 mm/s) from YSn₂ to YNiSn₂, indicating decrease of the s electron density at the tin nuclei.     

The Stannides YNi x Sn2 ( x = 0, 0.14, 0.21, 1) – Syntheses, Structure, and 119Sn M?ssbauer Spectroscopy

Summary. The stannides YNi _x Sn₂ (x = 0, 0.14, 0.21, 1) were prepared by arc-melting of the pure elements. They were characterized through X-ray powder and single crystal data: ZrSi₂ type, space group Cmcm, a = 438.09(6), b = 1629.6(4), c = 430.34(7) pm, wR2 = 0.0607, 386 F ² values, 14 variables for YSn₂, CeNiSi₂ type, Cmcm, a = 440.6(1), b = 1640.3(1), c = 433.0(1) pm, wR2 = 0.0632, 416 F ² values, 19 variables for YNi_0.142(7)Sn₂, a = 441.0(1), b = 1646.3(1), c = 434.6(1) pm, wR2 = 0.0491, 287 F ² values, 19 variables for YNi_0.207(7)Sn₂, and LuNiSn₂ type, space group Pnma, a = 1599.3(3), b = 440.89(5), c = 1456.9(2) pm, wR2 = 0.0375, 1538 F ² values, 74 variables for YNiSn₂. The YSn₂ structure contains Sn1–Sn1 zig-zag chains (297 pm) and planar Sn2 networks (307 pm). The stannides YNi_0.142(7)Sn₂ and YNi_0.207(7)Sn₂ are nickel filled versions of YSn₂. The nickel atoms have a distorted pyramidal tin coordination with Ni–Sn distances ranging from 220 to 239 pm. New stannide YNiSn₂ adopts the LuNiSn₂ type. The nickel and tin atoms build up a complex three-dimensional [NiSn₂] network in which the yttrium atoms fill distorted pentagonal and hexagonal channels. Within the network all nickel atoms have a distorted square pyramidal tin coordination with Ni–Sn distances ranging from 247 to 276 pm. Except the Sn4 atoms which are located in a tricapped trigonal Y₆ prism, all tin atoms have between 4 and 5 tin neighbors between 297 and 350 pm. ¹¹⁹Sn M?ssbauer spectroscopic data of YNi _x Sn₂ show a decreasing isomer shift (from 2.26 to 2.11 mm/s) from YSn₂ to YNiSn₂, indicating decrease of the s electron density at the tin nuclei.     

Crystal and molecular structures of the Rh[(C2H5O)2PS2]3 and Co[(C6H5O)2PS2]3 chelate compounds

The crystal structures of the Rh[(EtO)₂PS₂]₃ (I) and Co[(PhO)₂PS₂]₃ (II) chelate compounds were determined from X-ray diffraction (XRD) data (CAD-4 diffractometer, MoK _β radiation, 1193 F _hkl , R = 0.0516 for I and 513 F _hkl , R = 0.0305 for II). Crystals I are monoclinic: a = 14.233(3) Å, b = 13.570(3) Å, c = 14.272(3) Å; β = 90.66(3)°, V = 2756.3(10) ų, Z = 4, ρ_calc = 1.587 g/cm³, space group C2/c. Crystals II are trigonal: a = 15.149(2) Å, c = 30.306(6) Å; V = 6023.2(16) ų, Z = 6, ρ_calc = 1.493 g/cm³, space group R3ˉ. Structures I and II consist of discrete mononuclear molecules. The coordination polyhedra of the M atoms (M = Rh, Co) are distorted octahedra formed by six sulfur atoms of three cyclic bidentate (RO)₂ PS₂⁻ ligands. Original Russian Text Copyright ? 2008 by R. F. Klevtsova, L. A. Glinskaya, and S. V. Larionov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 49, No. 2, pp. 330–334, March–April, 2008.     

Crystal and molecular structures of Ni[(iso-C4H9)2PS2]2 and Pd[(iso-C4H9)2PS2]2 chelates

Crystal structures of chelate compounds Ni[(iso-C₄H₉)₂PS₂]₂ (I) and Pd[(iso-C₄H₉)₂PS₂]₂ (II) have been determined by X-ray diffraction: diffractometer X8-APEX, MoK _α∔ -radiation, 1048 F _hkl , R = 0.0544 for I and CAD-4 diffractometer, MoK _α∔ -radiation, 1283 F _hkl , R = 0.0347 for II. The crystals are rhombic: a = 12.921(5) Å, b = 17.094(5) Å, c = 22.971(5) Å; V = 5074(3) ų, Z = 8, calc = 1.250 g/cm³, space group Pbca for I and a = 13.312(3) Å, b = 16.130(7) Å, c = 23.171(5) Å; V = 4975(3) ų, Z = 8, ρ_calc = 1. 208 g/cm³, space group Pbca for II. The structures of I and II are formed by discrete mononuclear molecules. Coordination cores MS₄ (M = Ni, Pd) approach planar square configurations. Original Russian Text Copyright ? 2005 by L. A. Glinskaya, T. G. Leonova, T. E. Kokina, R. F. Klevtsova, and S. V. Larionov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 46, No. 4, pp. 715–720, July–August, 2005.     

Crystal and molecular structure of (NH4)2[UO2(NO3)4] and [(NH4)(18C6)]2[UO2(NO3)4]

Single crystals of diammonium tetranitratouranylate (NH₄)₂[UO₂(NO₃)₄] (I) and a new diammonium tetranitratouranylate complex with 18-crown-6 [(NH₄)(18C6)]₂[UO₂(NO₃)₄] (II) have been synthesized by the reaction of diaquadinitratouranyl tetrahydrate with ammonium nitrate in a nitric acid solution and the reaction of the same reagents with 18C6 in an ethanol solution, respectively. The X-ray diffraction analysis of compounds I and II has been performed. Crystals of compounds I and II are monoclinic, Z = 2, space group P2₁/n, a = 6.4075(5) ?, b = 7.7851(7) ?, c = 12.4461(12) ?, β = 101.239(1)°, V = 608. 94(9) ?³ for compound I and a = 10.542(9) ?, b = 8.590(8) ?, c = 22.5019(19) ?, β = 101.632(1)°, V = 2058.3(3) ?³ for compound II. The [UO₂(NO₃)₄]²⁻ complex anion in compounds I and II contains two monodentate and two bidentate cyclic nitrato groups, and the coordination number of uranyl is 6. The 18C6 molecule in the structure of compound II has the classic crown conformation and combined with the ammonium ion by three hydrogen bonds. Compounds I and II formed by electrostatic attraction forces between counterions are stabilized by (NH₄⁺)NH...O(NO₃⁻) interionic hydrogen bonds.     

Crystal structure and ionic conductivity of a new bismuth tungstate, Bi3W2O10.5

The compound Bi₃W₂O_10.5 was synthesized by the solid-state technique from Bi₂O₃ and WO₃ in stoichiometric quantities. Single crystals were grown by the melt-cooling technique and the crystal structure was solved in the tetragonalI4/m space group witha = 3.839 (1) ?,c = 16.382 (5) ?,V = 241.4 (1) ?³,Z = 4 and was refined to anR inde_x of 0.0672. The structure represents a modification of the Aurivillius phase and consists of [Bi₂O₂]²⁺ units separated by WO₈ polyhedra. a.c. impedance studies indicate oxide ion conductivity of 2.91 10⁻⁵ Scm⁻¹ at 600°C. Dedicated to Prof J Gopalakrishnan on his 62nd birthday.     

Semiconducting La2AuP3, the Metallic Conductor Ce2AuP3, and other Rare‐Earth Gold Phosphides Ln2AuP3 with Two Closely Related Crystal Structures

The compounds Ln₂AuP₃ were synthesized by reaction of the elemental components in evacuated silica tubes. Their crystal structures were determined from single‐crystal diffractometer data. The compounds with Ln = La, Ce, and Pr crystallize with an orthorhombic U₂NiC₃ type structure (Pnma, Z = 4). The structure refinement for Ce₂AuP₃ resulted in a = 774.14(6) pm, b = 421.11(4) pm, c = 1612.3(1) pm, R = 0.019 for 1410 structure factors and 38 variable parameters. For Pr₂AuP₃ a residual of R = 0.024 was obtained. Nd₂AuP₃ crystallizes with a monoclinic distortion of this structure: P2₁/c, Z = 4, a = 416.14(4) pm, b = 768.87(6) pm, c = 1647.1(2) pm, β = 104.06(1)°, R = 0.022 for 1361 F values and 56 variables. The near‐neighbor coordinations of the two structures are nearly the same. In both structures the gold and phosphorus atoms form two‐dimensionally infinite nets, where the gold atoms are tetrahedrally coordinated by phosphorus atoms with Au–P distances varying between 245.8 and 284.2 pm. Two thirds of the phosphorus atoms form pairs with single‐bond distances varying between 217.7 and 218.9 pm. Thus, using oxidation numbers the structures can be rationalized with the formulas (Ln⁺³)₂[AuP₃]^–6 and (Ln⁺³)₂Au⁺¹(P₂)^–4P^–3. Accordingly, La₂AuP₃ is a diamagnetic semiconductor. Pr₂AuP₃ is semiconducting with an antiferromagnetic ground state, showing metamagnetism with a critical field of B_c = 0.5(± 0.1) T. In contrast, the cerium compound is a metallic conductor, even though its cell volume indicates that the cerium atoms are essentially trivalent, as is also suggested by the ferro‐ or ferrimagnetic behavior of the compound.     

Structure and Magnetic Properties of Ce3Ge0.66In4.34 and Ce11Ge4.74In5.26

New indides Ce₃Ge_0.66In_4.34 and Ce₁₁Ge_4.74In_5.26 were synthesized from the elements by arc‐melting and subsequent annealing at 870 K. Single crystals were grown through special annealing procedures in sealed tantalum tubes in a high‐frequency furnace. Both compounds were investigated on the basis of X‐ray powder and single crystal data: I4/mcm, La₃GeIn₄ type, a = 848.8(1), c = 1192.0(2) pm, Z = 4, wR2 = 0.0453, 499 F² values, 17 variables for Ce₃Ge_0.66In_4.34 and I4/mmm, Sm₁₁Ge₄In₆ type (ordered version of the Ho₁₁Ge₁₀ type), a = 1199.3(2), c = 1662.0(3) pm, wR2 = 0.0507, 1217 F² values, 41 variables for Ce₁₁Ge_4.74In_5.26. The Ce₃Ge_0.66In_4.34 structure shows a mixed Ge/In occupancy on the 4c Wyckoff position. This site is octahedrally coordinated by cerium atoms. These octahedra share all edges, leading to a three‐dimensional network. The latter is penetrated by a two‐dimensional indium substructure which consists of flattened tetrahedra at In–In distances of 291 and 300 pm. The Ce₁₁Ge_4.74In_5.26 structure contains three crystallographically independent germanium sites. The latter are coordinated by eight or nine cerium neighbors. These CN8 and CN9 polyhedra are condensed to a complex network which is penetrated by a three‐dimensional indium network with In–In distances of 301–314 pm. The 16m site shows a mixed In/Ge occupancy. Chemical bonding in both compounds is dominated by the p elements. Both ternaries studied exhibit localized magnetism due to the presence of Ce³⁺ ions. The compound Ce₃GeIn₄ remains paramagnetic down to 1.72 K, whereas Ce₁₁Ge₄In₆ orders ferromagnetically at T_C = 7.5 K.     

On the characterization of BiMO2NO3 (M=Pb, Ca, Sr, Ba) materials related with the Sillén X1 structure

The compounds BiMO₂NO₃, with M=Pb, Ca, Sr, and Ba, were obtained as single-phase products from solid-state reactions in an atmosphere of nitrous gases. The oxide nitrates with Pb and Ca crystallize in the tetragonal space group I4/mmm with two formula units per unit cell; the oxide nitrates with Sr and Ba crystallize in the orthorhombic space group Cmmm with four formula units per unit cell. Lattice parameters at room temperature are a=397.199(4), c=1482.57(2) pm for M=Pb; a=396.337(5), c=1412.83(3) pm for M=Ca; a=1448.76(3), b=567.62(1), c=582.40(1) pm for M=Sr and a=1536.50(8), b=571.67(3), c=597.55(3) pm for M=Ba. The structures, which were refined by powder X-ray diffraction, consist of alternating [BiMO₂]⁺ and [NO₃]⁻ layers stacked along the direction of the long axis. IR and thermogravimetric data are also given. The various M²⁺ cations in BiMO₂NO₃ are compatible with each other; therefore and because of their layer-type structure, these compounds are interesting precursors for oxide materials, e.g., the HTSC compounds (Bi,Pb)₂Sr₂Ca_n−1Cu_nO_x.     

High-temperature synthesis, single-crystal X-ray structure determination and solid-state NMR investigations of Ba7[SiO4][BO3]3CN and Sr7[SiO4][BO3]3CN

The novel alkaline earth silicate borate cyanides Ba₇[SiO₄][BO₃]₃CN and Sr₇[SiO₄][BO₃]₃CN have been obtained by the reaction of the respective alkaline earth metals M=Sr, Ba, the carbonates M^IICO₃, BN, and SiO₂ using a radiofrequency furnace at a maximum reaction temperature of 1350°C and 1450°C, respectively. The crystal structures of the isotypic compounds M^II₇[SiO₄][BO₃]₃CN have been determined by single-crystal X-ray crystallography (P6₃mc (no. 186), Z=2, a=1129.9(1) pm, c=733.4(2) pm, R₁=0.0336, wR₂=0.0743 for M^II=Ba and a=1081.3(1) pm, c=695.2(1) pm, R₁=0.0457, wR₂=0.0838 for M^II=Sr). Both ionic compounds represent a new structure type, and they are the first examples of silicate borate cyanides. The cyanide ions are disordered and they are surrounded by Ba²⁺/Sr²⁺ octahedra, respectively. These octahedra share common faces building chains along [001]. The [BO₃]³⁻ ions are arranged around these chains. The [SiO₄]⁴⁻ units are surrounded by Ba²⁺/Sr²⁺ tetrahedra, respectively. The title compounds additionally have been investigated by ¹¹B, ¹³C, ²⁹Si, and ¹H MAS-NMR as well as IR and Raman spectroscopy confirming the presence of [SiO₄]⁴⁻, [BO₃]³⁻, and CN⁻ ions.     

New manganites NdM3Sr3Mn4O12 and NdM3Ba3Mn4O12 (M = Li, Na, K): Synthesis and X-ray diffraction characteristics

Manganites NdM₃Sr₃Mn₄O₁₂ and NdM₃Ba₃Mn₄O₁₂ (M = Li, Na, K) were synthesized by a ceramic method from the corresponding oxides and carbonates. The X-ray diffraction analysis showed that all the compounds crystallized in the tetragonal crystal system with the following lattice parameters: NdLi₃Sr₃Mn₄O₁₂: a = 10.88 ?, c = 9.52 ?, V ^o = 1126.9 ?³, Z = 4, ρ_X = 4.95 g/cm³, ρ_pycn = 4.87 ± 0.05 g/cm³; NdNa₃Sr₃Mn₄O₁₂: a = 10.73 ?, c = 10.66 ?, V ^o = 1227.3 ?³, Z = 4, ρ_X = 4.80 g/cm³, ρ_pycn = 4.73 ± 0.07 g/cm³; NdK₃Sr₃Mn₄O₁₂: a = 10.87 ?, c = 11.71 ?, V ^o = 1382.6 ?³, Z = 4, ρ_X = 4.50 g/cm³, ρ_pycn = 4.43 ± 0.09 g/cm³; NdLi₃Ba₃Mn₄O₁₂: a = 10.97 ?, c = 10.34 ?, V ^o = 1244.3 ?³, Z = 4, ρ_X = 5.33 g/cm³, ρ_pycn = 5.23 ± 0.09 g/cm³; NdNa₃Ba₃Mn₄O₁₂: a = 10.99 ?, c = 11.15 ?, V ^o = 1346.7 ?³, Z = 4; ρ_X = 5.11 g/cm³, ρ_pycn = 5.05 ± 0.06 g/cm³; NdK₃Ba₃Mn₄O₁₂: a = 10.997 ?; c = 13.80 ?, V ^o = 1668.9 ?³, Z = 4, ρ_X = 4.32 g/cm³, ρ_pycn = 4.26 ± 0.07 g/cm³. Original Russian Text ? B.K. Kasenov, E.S. Mustafin, M.A. Akubaeva, S.T. Edil’baeva, Sh.B. Kasenova, Zh.I. Sagintaeva, S.Zh. Davrenbekov, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 3, pp. 424–427.     

Synthesis and crystal structure of the palladium oxides NaPd3O4, Na2PdO3 and K3Pd2O4

NaPd₃O₄, Na₂PdO₃ and K₃Pd₂O₄ have been prepared by solid-state reaction of Na₂O₂ or KO₂ and PdO in sealed silica tubes. Crystal structures of the synthesized phases were refined by the Rietveld method from X-ray powder diffraction data. NaPd₃O₄ (space group Pm3¯n, a=5.64979(6) Å, Z=2) is isostructural to NaPt₃O₄. It consists of NaO₈ cubes and PdO₄ squares, corner linked into a three-dimensional framework where the planes of neighboring PdO₄ squares are perpendicular to each other. Na₂PdO₃ (space group C2/c, a=5.3857(1) Å, b=9.3297(1) Å, c=10.8136(2) Å, β=99.437(2)°, Z=8) belongs to the Li₂RuO₃-structure type, being the layered variant of the NaCl structure, where the layers of octahedral interstices filled with Na⁺ and Pd⁴⁺ cations alternate with Na₃ layers along the c-axis. Na₂PdO₃ exhibits a stacking disorder, detected by electron diffraction and Rietveld refinement. K₃Pd₂O₄, prepared for the first time, crystallizes in the orthorhombic space group Cmcm (a=6.1751(6) Å, b=9.1772(12) Å, c=11.3402(12) Å, Z=4). Its structure is composed of planar PdO₄ units connected via common edges to form parallel staggered PdO₂ strips, where potassium atoms are located between them. Magnetic susceptibility measurements of K₃Pd₂O₄ reveal a Curie-Weiss behavior in the temperature range above 80 K.     

Syntheses, structures, optical properties, and theoretical calculations of Cs2Bi2ZnS5, Cs2Bi2CdS5, and Cs2Bi2MnS5

Three new compounds, Cs₂Bi₂ZnS₅, Cs₂Bi₂CdS₅, and Cs₂Bi₂MnS₅, have been synthesized from the respective elements and a reactive flux Cs₂S₃ at 973 K. The compounds are isostructural and crystallize in a new structure type in space group Pnma of the orthorhombic system with four formula units in cells of dimensions at 153 K of a=15.763(3), b=4.0965(9), c=18.197(4) Å, V=1175.0(4) Å³ for Cs₂Bi₂ZnS₅; a=15.817(2), b=4.1782(6), c=18.473(3)  Å, V=1220.8(3)  ų for Cs₂Bi₂CdS₅; and a=15.830(2), b=4.1515(5), c=18.372(2) Å, V=1207.4(2) Å³ for Cs₂Bi₂MnS₅. The structure is composed of two-dimensional _∞²[Bi₂MS₅²⁻] (M=Zn, Cd, Mn) layers that stack perpendicular to the [100] axis and are separated by Cs⁺ cations. The layers consist of edge-sharing _∞¹[Bi₂S₆⁶⁻] and _∞¹[MS₃⁴⁻] chains built from BiS₆ octahedral and MS₄ tetrahedral units. Two crystallographically unique Cs atoms are coordinated to S atoms in octahedral and monocapped trigonal prismatic environments. The structure of Cs₂Bi₂MS₅, is related to that of Na₂ZrCu₂S₄ and those of the AMM′Q₃ materials (A=alkali metal, M=rare-earth or Group 4 element, M′= Group 11 or 12 element, Q=chalcogen). First-principles theoretical calculations indicate that Cs₂Bi₂ZnS₅ and Cs₂Bi₂CdS₅ are semiconductors with indirect band gaps of 1.85 and 1.75 eV, respectively. The experimental band gap for Cs₂Bi₂CdS₅ is ≈1.7 eV, as derived from its optical absorption spectrum.     

Crystal structure of [Pd(P(i-Pr)3)2(acac)]BF4

A single crystal X-ray diffraction study is carried out for [Pd(P(i-Pr)₃)₂(acac)]BF₄, T = 150(2) K. Crystal data: a = 10.2935(4) ?, b = 11.3591(5) ?, c = 13.8728(6) ?, α = 89.154(2)°, β = 68.448(1)°, γ = 85.032(1)°, P-1 space group, V = 1502.75(11) ?³, Z = 2, d _x = 1.354 g/cm³.