Neue thermische Abbauprodukte von Ln2CeMO6Cl3 (M = Nb,Ta; Ln = La–Sm) – Darstellung von strukturverwandtem (La, Tb)3,5TaO6Cl4–x

Contributions on the Investigation of Inorganic Nonstoichiometric Compounds. XLV. New Thermal Decomposition Products of Ln₂CeMO₆Cl₃ – Preparation of Structure‐related (La, Tb)_3.5TaO₆Cl_4–x The thermal decomposition (T £ 900–1050°C) of Ln₂CeMO₆Cl₃ (M = Nb, Ta; Ln = La, Ce, Pr, Nd, Sm) leads to the formation of two mixed‐valenced phases (Ln, Ce)_3.25MO₆Cl_3.5–x (phase ‘‘AB”︁”︁) and (Ln, Ce)_3.5MO₆Cl_4–x (phase ‘‘BB”︁”︁) and to the formation of chlorine according to redox‐reactions between Ce⁴⁺ and Cl^–. Single crystals of both phases (Ln, Ce)_3.25MO₆Cl_3.5–x (‘‘AB”︁”︁) and (Ln, Ce)_3.5MO₆Cl_4–x (‘‘BB”︁”︁) were obtained by chemical transport reactions using both powder of Ln₂CeMO₆Cl₃ (phase ‘‘A”︁”︁) and powder of (Ln, Ce)_3.25MO₆Cl_3.5–x (phase ‘‘AB”︁”︁) as starting materials and chlorine (p{Cl₂; 298 K} = 1 atm) or HCl (p{HCl; 298 K} = 1 atm) as transport agent. A crystal of (La, Ce)_3.25NbO₆Cl_3.5–x (”︁AB”︁”︁) (space group: C2/m, a = 35.288(1) Å, b = 5.418(5) Å, c = 9.522(1) Å, β = 98.95(7)°, Z = 4) was investigated by x‐ray diffraction methods, a crystal of (Pr, Ce)_3.5NbO₆Cl_4–x (”︁BB”︁”︁) was investigated by synchrotron radiation (λ = 0.56 Å) diffraction methods. The lattice constants are a = 18.863(6) Å, b = 5.454(5) Å, c = 9.527(6) Å, β = 102.44(3)° and Z = 4. Structure determination in the space group C2/m (No. 12) let to R1 = 0.0313. Main building units are NbO₆‐polyhedra with slightly distorted trigonally prismatic environment for Nb and chains of face‐sharing Cl₆‐octahedra along [010]. The rare earth ions are coordinated by chlorine and oxygen atoms. These main structure features confirmed the expected relation to the starting material Ln₂CeMO₆Cl₃ (phase ”︁A”︁”︁) and to (Ln, Ce)_3.25MO₆Cl_3.5–x (phase ”︁AB”︁”︁).     

Synthese und Kristallstruktur von Y(HSO4)3-I und Y(HSO4)3 · H2O

Syntheses and Crystal Structures of Y(HSO₄)₃-I and Y(HSO₄)₃ · H₂O Lath shaped crystals of Y(HSO₄)-I are obtained by treatment of Y₂O₃ with conc. sulfuric acid at 200 °C. Y(HSO₄)₃-I crystallizes orthorhombic (Pbca, Z = 8, a = 1201.5(1), b = 953.76(8), c = 1650.4(1) pm, R_all = 0.0388). In the crystal structure Y³⁺ is coordinated by eight monodentate HSO₄^– groups. Colorless, plate like single crystals of Y(HSO₄)₃ · H₂O grew from a solution of Y₂O₃ in 85% sulfuric acid upon cooling. In the crystal structure of the triclinic compound (P1, Z = 2, a = 679.8(1), b = 802.8(2), c = 965.9(2) pm, α = 79.99(2)°, β = 77.32(2)°, γ = 77.50(2)°, R_all = 0.0264) Y³⁺ is surrounded by seven HSO₄^– groups and one molecule of water.     

Synthesis and Structure of Anhydrous Rare‐Earth Perchlorates M(ClO4)3 (M = La,Ce–Er,Y): Derivatives of the UCl3 Type of Structure

Anhydrous perchlorates M(ClO₄)₃ (M = La, Ce–Er, Y) were obtained by drying the products formed in the reaction of the respective lanthanide oxide with perchloric acid (70%). According to X‐ray powder investigations, they all crystallize with the hexagonal space group P6₃/m isostructural with the hydrogensulfates of the lighter lanthanides. For the example of Pr(ClO₄)₃ a full profile Rietveld refinement based on X‐ray powder data has been undertaken successfully (a = 933.61(3) pm, c = 584.88(2) pm; R_p = 0.207, R_Bragg = 0.068). The structure of Er(ClO₄)₃ was refined from neutron diffraction data (a = 919.7(1) pm, c = 559.8(1) pm; R_p = 0.190, R_Bragg = 0.106). High temperature X‐ray powder investigations show that thermal expansion occurs mainly in the (001) plane while the c axis remains nearly constant.     

Über Fluoridsulfide (MFS) der Lanthanide (M = La–Nd,Sm, Gd–Lu) im A‐Typ mit PbFCl‐Struktur

On Fluoride Sulfides (MFS) of the Lanthanides (M = La–Nd, Sm, Gd–Lu) with A‐ or PbFCl‐Type Crystal Structure By the reaction of the elemental lanthanides (M = La–Nd, Sm–Lu) with the respective trifluorides (MF₃) and sulfur (S) in 2 : 1 : 3‐molar ratios at 850 °C, single‐phase fluoride sulfides of the composition MFS can be obtained in evacuated, gas‐tightly arc‐welded niobium or tantalum capsules within a few days. Exceptions are europium and ytterbium which do not react to form the corresponding fluoride sulfides under these conditions. However, at least YbFS becomes accessible through this method if platinum serves as container material. With sodium chloride (NaCl) as a flux, the formation of hydrolysis‐insensitive, platelet‐shaped A‐type single crystals with square cross‐section and the formula MFS (M = La–Nd, Sm, Gd–Er) is possible. These are very suitable for structure refinement from X‐ray diffraction data. In the PbFCl‐analogous crystal structures (tetragonal, P4/nmm, Z = 2; LaFS: a = 404.38(4), c = 700.41(7) pm; CeFS: a = 400.13(3), c = 696.20(5) pm; PrFS: a = 396.27(3), c = 692.72(5) pm; NdFS: a = 393.89(3), c = 691.58(5) pm; SmFS: a = 388.36(3), c = 687.95(5) pm; GdFS: a = 383.45(3), c = 685.18(5) pm; TbFS: a = 381.02(3), c = 683.86(5) pm; DyFS: a = 378.48(2), c = 682.51(4) pm; HoFS: a = 376.48(3), c = 681.92(5) pm; ErFS: a = 374.61(3), c = 681.34(5) pm), the M³⁺ cations are surrounded by nine anions (4 F^– and 5 S^2–) as monocapped square antiprisms. The anions themselves exhibit tetrahedral (F^–) and square‐pyramidal (S^2–) cationic coordination, respectively, according to the Niggli formula {(M³⁺)(F^–)_4/4(S^2–)_5/5}. In the case of TmFS, YbFS, and LuFS under analogous conditions, the hexagonal B‐ or trigonal C‐type modifications form at first, which can be transformed eventually to the quenchable metastable tetragonal A‐type polymorphs (TmFS: a = 372.86(5), c = 681.15(8) pm; YbFS: a = 371.08(5), c = 680.93(8) pm; LuFS: a = 369.37(5), c = 680.76(8) pm) at high pressure (20–60 kbar).     

Der UCl3‐Typ mit komplexen Anionen und seine Additions‐Substitutions‐Variante: Synthese und Kristallstruktur von Nd(ClO4)3 und Na0, 75Nd0, 75(ReO4)3

The UCl₃ Type of Structure with Complex Anions and its Addition‐Substitution Variant: Syntheses and Crystal Structure of Nd(ClO₄)₃ and Na_{0, 75}Nd_{0, 75}(ReO₄)₃ Pale violet single crystals of Nd(ClO₄)₃ (hexagonal, P6₃/m, Z = 2, a = 933.0(1), c = 560.08(5) pm, R_all = 0.0422) were obtained by careful dehydration of Nd(ClO₄)₃·6H₂O under flowing argon at 220 °C. Hexagonal single crystals of Na_{0, 75}Nd_{0, 75}(ReO₄)₃ (P6₃/m, Z = 2, a = 1000.0(1), c = 636.08(5) pm, R_all = 0.0206) show the same colour and are formed in the reaction of Nd(ReO₄)₃ with excess NaCl at 820 °C. Single phase powder samples can be obtained by a solid state reaction of NaReO₄ and Nd(ReO₄)₃ in evacuated silica tubes at elevated temperatures.     

Synthese und Struktur der Nitridoborat‐Nitride Ln4(B2N4)N (Ln = La,Ce) des Formeltyps Ln3+x(B2N4)Nx (x = 0, 1, 2)

Synthesis and Structure of Nitridoborate Nitrides Ln₄(B₂N₄)N (Ln = La, Ce) of the Formula Type Ln_3+x(B₂N₄)N_x (x = 0, 1, 2) The missing member of the formula type Ln_3+x(B₂N₄)N_x with x = 1 was synthesized and characterized for Ln = La and Ce. According to the single‐crystal X‐ray structure solution Ce₄(B₂N₄)N crystallizes in the space group C2/m (Z = 2) with the lattice parameters a = 1238.2(1) pm, b = 357.32(3) pm, c = 905.21(7) pm and β = 129.700(1)°. The anisotropic structure refinement converged at R1 = 0.039 and wR2 = 0.099 for all independent reflections. A powder pattern of La₄(B₂N₄)N was indexed isotypically with a = 1260.4(1) pm, b = 366.15(3) pm, c = 919.8(1) pm and β = 129.727(6)°. A structure rational for nitridoborates and nitridoborate nitrides containing B₂N₄ ions with the general formula Ln_3+x(B₂N₄)N_x with x = 0, 1, 2 is presented.     

Hydrogenselenate der Selten‐Erd‐Elemente: Synthese und Kristallstruktur von La(HSeO4)3 und Gd(HSeO4)(SeO4)

Hydrogenselenates of Rare Earth Elements: Syntheses and Crystal Structures of La(HSeO₄)₃ and Gd(HSeO₄)(SeO₄) Colorless transparent single crystals of La(HSeO₄)₃ (hexagonal, P6₃/m, Z = 2, a = 971.7(1), c = 616.98(8) pm, R_all = 0.0440) were obtained from the reaction of La₂O₃ and conc. selenic acid. La(HSeO₄)₃ is isotypic with the corresponding hydrogensulfate. Its structure can be seen as a variant of the UCl₃ type structure with complex anions and contains the La³⁺ ions in ninefold coordination of oxygen atoms. Single crystals of Gd(HSeO₄)(SeO₄) crystallize from a solution of Gd₂O₃ in selenic acid (70% H₂SeO₄). In the orthorhombic crystal structure (Pbca, Z = 8, a = 920.4(1), b = 1351.6(2), c = 1004.0(1) pm, R_all = 0.0276) the Gd³⁺ ions are coordinated by eight oxygen atoms belonging to four SeO₄^2– and four HSeO₄^– ions. These are surrounded by four Gd³⁺ ions.     

Sulfate und Hydrogensulfate des Erbiums: Er(HSO4)3-I,Er(HSO4)3-II,Er(SO4)(HSO4) und Er2(SO4)3

Sulfates and Hydrogensulfates of Erbium: Er(HSO₄)₃-I, Er(HSO₄)₃-II, Er(SO₄)(HSO₄), and Er₂(SO₄)₃ Rod shaped light pink crystals of Er(HSO₄)₃-I (orthorhombic, Pbca, a = 1195.0(1) pm, b = 949.30(7) pm, c = 1644.3(1) pm) grow from a solution of Er₂(SO₄)₃ in conc. H₂SO₄ at 250 °C. From slightly diluted solutions (85%) which contain Na₂SO₄, brick shaped light pink crystals of Er(HSO₄)₃-II (monoclinic, P2₁/n, a = 520.00(5) pm, b = 1357.8(1) pm, c = 1233.4(1) pm, β = 92.13(1)°) were obtained at 250 °C and crystals of the same colour of Er(SO₄)(HSO₄) (monoclinic, P2₁/n, a = 545.62(6) pm, b = 1075.6(1) pm, c = 1053.1(1) pm, β = 104.58(1)°) at 60 °C. In both hydrogensulfates, Er³⁺ is surrounded by eight oxygen atoms. In Er(HSO₄)₃-I layers of HSO₄^– groups are connected only via hydrogen bridges, while Er(HSO₄)₃-II consists of a threedimensional polyhedra network. In the crystal structure of Er(SO₄)(HSO₄) Er³⁺ is sevenfold coordinated by oxygen atoms, which belong to four SO₄^2–- and three HSO₄^–-tetrahedra, respectively. The anhydrous sulfate, Er₂(SO₄)₃, cannot be prepared from H₂SO₄ solutions but crystallizes from a NaCl-melt. The coordination number of Er³⁺ in Er₂(SO₄)₃ (orthorhombic, Pbcn, a = 1270.9(1) pm, b = 913.01(7) pm, c = 921.67(7) pm) is six. The octahedral coordinationpolyhedra are connected via all vertices to the SO₄^2–-tetrahedra.     

Einkristallstrukturuntersuchungen an hexagonalen Fluorperowskiten AMIIF3 (MII = Mg,Mn, Fe,Co, Ni)

Single Crystal Structural Studies at Hexagonal Fluoride Perovskites AM^IIF₃ (M^II = Mg, Mn, Fe, Co, Ni) At single crystals of nine fluoride phases AMF₃ the hexagonal perovskite structures were refined by X‐ray methods, of RbNiF₃ below T_C £ 145 K, too. The hexagonal 6 L type (P6₃/mmc, Z = 6) is found at: RbMgF₃ (a = 585.7(1); c = 1426.0(1) pm), CsMnF₃ (624.4(1); 1515.4(4) pm), CsFeF₃ (616.8(1); 1488.4(6) pm), Rb_0.63Cs_0.37CoF₃ (599.1(1); 1460.3(4) pm), RbNiF₃ (128 K: 582.6(1); 1426.4(6) pm), Cs₂BaLiNi₂F₉ (593.1(1); 1447.1(4) pm). Of the hexagonal‐rhombohedral 9 L type (R 3 m, Z = 9) are CsCoF₃ (620.1(1); 2264.0(7) pm) and yellow CsNiF₃ (614.7(1); 2235.3(6) pm), prepared at lower temperatures resp. under high pressure, whereas light green CsNiF₃ (625.5(1); 524.2(1) pm) belongs to the 2 L type (P6₃/mmc, Z = 2). The occurence of these structures and the interatomic distances observed, comparing also normal and high pressure phases, are discussed in connection with the tolerance factor.     

Saure Sulfate des Neodyms: Synthese und Kristallstruktur von (H5O2)(H3O)2Nd(SO4)3 und (H3O)2Nd(HSO4)3SO4

Acidic Sulfates of Neodymium: Synthesis and Crystal Structure of (H₅O₂)(H₃O)₂Nd(SO₄)₃ and (H₃O)₂Nd(HSO₄)₃SO₄ Light violett single crystals of (H₅O₂)(H₃O)₂ · Nd(SO₄)₃ are obtained by cooling of a solution prepared by dissolving neodymium oxalate in sulfuric acid (80%). According to X‐ray single crystal investigations there are H₃O⁺ ions and H₅O₂⁺ ions present in the monoclinic structure (P2₁/n, Z = 4, a = 1159.9(4), b = 710.9(3), c = 1594.7(6) pm, β = 96.75(4)°, R_all = 0.0260). Nd³⁺ is nine‐coordinate by oxygen atoms. The same coordination number is found for Nd³⁺ in the crystal structure of (H₃O)₂Nd(HSO₄)₃SO₄ (triclinic, P1, Z = 2, a = 910.0(1), b = 940.3(1), c = 952.6(1) pm, α = 100.14(1)°, β = 112.35(1)°, γ = 105.01(1)°, R_all = 0.0283). The compound has been prepared by the reaction of Nd₂O₃ with chlorosulfonic acid in the presence of air. In the crystal structure both sulfate and hydrogensulfate groups occur. In both compounds pronounced hydrogen bonding is observed.     

Sulfidchloride (MSCl) der leichten Lanthanide (M = La–Pr)

Sulfide Chlorides (MSCl) of the Light Lanthanides (M = La–Pr) The reactions of the light lanthanides (M = La–Nd) with sulfur and the respective trichlorides (MCl₃) in evacuated silica tubes (850 °C, 7 d) yield single-phase sulfide chlorides of the composition MSCl when appropriate molar ratios (2 : 3 : 1) of the reactants (M : S : MCl₃) are used. A slight excess of trichloride as a flux promotes the formation of lath-shaped transparent single crystals (colorless for M = La and Ce, apple-green for M = Pr) which prove to be water soluble and sensitive to hydrolysis. The crystal structure was determined from X-ray single-crystal data taking LaSCl (orthorhombic, Pbcm (no. 57), a = 680.22(5), b = 705.26(7), c = 4203.7(3) pm, Z = 24, R = 0.069, R_w = 0.043) as an example. According to Guinier powder data CeSCl and quickly quenched samples of PrSCl crystallize isotypically. Thus four crystallographically independent cations (M³⁺) are present, each coordinated by four S^2– but differing in the number of their next Cl^– neighbors. The figures of coordination are completed by four Cl^– about M1 (square antiprism, CN = 8), by only two Cl^– about M2 (trigonal prism, CN = 6), and by three Cl^– each about M3 and M4 (capped trigonal prisms, CN = 7). Six crystallographically different anions, although indistinguishable by X-ray diffraction, exhibit coordination numbers of four (S^2–, 3 ×) and three (Cl^–, 3 ×) with respect to the cations. So PbO-analogous layers of the composition [SM_4/4]⁺ parallel (100) are formed and held together along [100] by alternatingly sheathed Cl^– layers.     

Nitridsulfidchloride der Lanthanide: I. Der Formeltyp M4NS3Cl3 (M = La?Nd)

Nitride Sulfide Chlorides of the Lanthanides. I. The Composition M₄NS₃Cl₃ (M = La Nd) The oxidation of the „light”︁ lanthanides (M = La Nd) with sulfur and NaN₃ the presence of the chlorides MCl₃ results in the formation of the first lanthanide nitride sulfide chlorides M₄NS₃Cl₃ when appropriate molar ratios of the reactants are used. The addition of some NaCl (or an excess of MCl₃) as a flux secures complete and fast reaction (7 d) at 850°C in evacuated silica vessels as well as single-crystalline products. Since these nitride sulfide chlorides (fine transparent needles) are not sensitive against hydrolysis, the surplus chloride can be removed easily with water. The crystal structure was determined from X-ray single crystal data for the example of La₄NS₃Cl₃ (hexagonal, P6₃mc (no. 186), Z = 2, a = 941.40(3), c = 700.36(3) pm, R = 0.026, R_w = 0.021) and the nitride sulfide chlorides M₄NS₃Cl₃ with M = Ce Nd proved to be isostructural from Guinier powder data. According to their Ba₃OCl₆-analogue structure, two crystallographically different M³⁺ cations are present (CN(M1) = 10, CN(M2) = 8). „Isolated”︁ tetrahedra [(N³⁻)(M³⁺)₄] build up the Mayn structural feature according to [NM₄]S₃Cl₃. They are hexagonally closest packed and interconnected via the crystallographically different but by X-ray diffraction indistinguishable anions S²⁻ and Cl⁻, which take care for charge neutrality.     

Nd(S2O7)(HSO4): Das erste Disulfat eines Selten‐Erd‐Elementes

Nd(S₂O₇)(HSO₄): The First Disulfate of a Rare Earth Element Light violett single crystals of Nd(S₂O₇)(HSO₄) have been obtained by the reaction of Nd₂O₃ and oleum (30% SO₃) at 200 °C in sealed glass ampoules. The crystal structure (monoclinic, P2₁/n, Z = 4, a = 857.8(1), b = 1061.0(2), c = 972.4(1) pm, β = 99.33(2)°) contains Nd³⁺ in eightfold coordination of oxygen atoms which belong to three HSO₄^– ions and four S₂O₇^2– groups. One of the latter acts as bidentate ligand. Hydrogen bonding is observed between the H atom of the HSO₄^– ion and the non‐coordinating O atom of the S₂O₇^2– group.     

Phosphaniminato‐Komplexe des Hafniums. Die Kristallstrukturen von [Hf(NPPh3)4] · 3 THF und [Hf(NPPh3)2Cl2(HNPPh3)2]

Phosphoraneiminato Complexes of Hafnium. Crystal Structures of [Hf(NPPh₃)₄] · 3 THF and [Hf(NPPh₃)₂Cl₂(HNPPh₃)₂] The phosphoraneiminato complexes [Hf(NPPh₃)₄] · 3 THF ( 1 · 3 THF) and [Hf(NPPh₃)₂Cl₂(HNPPh₃)₂] ( 2 ) have been prepared as colourless, moisture sensitive single crystals by reactions of hafnium tetrachloride with [CsNPPh₃]₄ · 2 toluene in tetrahydrofurane solutions by application of different ratios of the educts. Both complexes are characterized by IR spectroscopy and X‐ray crystal structure determinations. 1 · 3 THF: space group P 1, Z = 4, lattice dimensions at 193 K: a = 2007.6(1); b = 2064.2(1); c = 2115.9(1) pm; α = 109.193(4)°; β = 111.285(4)°; γ = 96.879(4)°; R₁ = 0.0506. 1 forms monomeric molecules with tetrahedral coordination of the nitrogen‐atoms of the (NPPh₃^–)‐groups towards the Hafnium atom. The HfN distances of 200.9 pm in average correspond with double bonds. 2 : space group P 1, Z = 4, lattice dimensions at 193 K: a = 1444.0(1); b = 1928.1(1); c = 2455.8(2) pm; α = 67.273(8)°; β = 87.445(8)°; γ = 87.082(8)°; R₁ = 0.0312. 2 has a monomeric molecular structure with octahedral coordination of the hafnium atom. The chlorine atoms are in trans position to one another, whereas the nitrogen atoms of the phosphoraneiminato groups (NPPh₃^–) are in trans position towards the nitrogen atoms ot the phosphorane imine molecules (HNPPh₃). The HfN bond lengths of the (NPPh₃^–) groups of 199.7 pm in average correspond with double bonds, whereas the HfN distances of the HNPPh₃ molecules with bond lengths of 230.2 pm in average are of donor‐acceptor type.     

The Nitrido Borates Ln3B2N4 (Ln = La–Nd) and La5B4N9: Syntheses,Structures, and Properties

Single crystals of the lanthanoide nitrido borates Ln₃B₂N₄ (Ln = La–Nd) and La₅B₄N₉ have been obtained from reactions of lanthanoide metal powder, lanthanoide nitride powder, and hexagonal boron nitride in calcium chloride melts. The isotypic compounds Ln₃B₂N₄ belong to the space group Immm (#71), Z = 2, with the lattice parameters for La₃B₂N₄: a = 362.94(3), b = 641.25(6), c = 1097.20(8) pm; Ce₃B₂N₄: a = 356.20(3), b = 631.90(6), c = 1071.91(8) pm; Pr₃B₂N₄: a = 353.46(4), b = 630.04(13), c = 1079.04(23) pm and Nd₃B₂N₄: a = 351.52(4), b = 627.01(15), c = 1075.59(23) pm. The structure of La₅B₄N₉ has been determined in the space group Pbcm (#57), Z = 4, with a = 988.25(5); b = 1263.48(7), c = 770.33(4) pm. These two structure types resemble three kinds of nitrido borate anions, the oxalate analogue B₂N₄ of Ln₃B₂N₄, and the carbonate analogue BN₃ together with the six‐membered ring system B₃N₆ of La₅(BN₃)(B₃N₆). In contrast to the valence compound La₅B₄N₉ the compounds (Ln³⁺)₃(B₂N₄)^8–(e^–) contain one electron in the conduction band, yielding temperature independent paramagnetism for La₃B₂N₄. The calculated electronic structure is developed through the formation of B₂N₄^8– ions by dimerisation of two BN₂ units.     

Neue Untersuchungen zum Reaktionsverhalten von Triorganylcyclotriphosphanen. Die Kristallstrukturen von [(PPh3)2Pt(PtBu)3], [(PPh3)2Pd(PtBu)2], [(CO)4Cr{(PiPr)3}2], [RhCl(PPh3)(PtBu)3], [(NiCO)6(μ2-CO)3{(PtBu)2}2] und [(CpFeCO)2(μ-CO)(μ-PHtBu)]+ · [FeCl3(thf)]–

New Research of Reaction Behaviour of Triorganylcyclotriphosphines. The Crystal Structures of [(PPh₃)₂Pt(P^tBu)₃], [(PPh₃)₂Pd(P^tBu)₂], [(CO)₄Cr{(PⁱPr)₃}₂], [RhCl(PPh₃)(P^tBu)₃], [(NiCO)₆(μ₂-CO)₃{(P^tBu)₂}₂], and [(CpFeCO)₂(μ-CO)(μ-PH^tBu)]⁺ · [FeCl₃(thf)]^– By the reaction of triorganylcyclotriphosphines with transition metal complexes single- and polynuclear compounds are formed, in which the cyclophosphines are bonded in different ways to the metal, the ring either preserving structure or under going ring opening. Depending on the reaction conditions the following compounds can be characterized: [(PPh₃)₂Pt(P^tBu)₃] ( 1 ), [(PPh₃)₂Pd(P^tBu)₂] ( 2 ), [(CO)₄Cr{(PⁱPr)₃}₂] ( 3 ), [RhCl(PPh₃)(P^tBu)₃] ( 4 ), [(NiCO)₆(μ₂-CO)₃{(P^tBu)₂}₂] ( 5 ) and [(CpFeCO)₂(μ-CO)(μ-PH^tBu)]⁺ · [FeCl₃(thf)]^– ( 6 ). The structures of 1 – 6 were obtained by X-ray single crystal structure analysis ( 1 : space group P2₁/n (No. 14), Z = 4, a = 1279.6(3) pm, b = 1733.1(4) pm, c = 2079.1(4) pm, β = 90.20(3)°; 2 : space group P2₁/c (No. 14), Z = 4, a = 1053.3(2) pm, b = 2085.2(4) pm, c = 1855.7(4) pm, β = 98.77(3)°; 3 : space group P 1 (No. 2), Z = 2, a = 1022.6(2) pm, b = 1026.4(2) pm, c = 1706.0(3) pm, α = 82.36(3)°, β = 86.10(3)°, γ = 64.40(3)°; 4 : space group P 1 (No. 2), Z = 2, a = 980.2(2) pm, b = 1309.5(3) pm, c = 1573.4(3) pm, α = 99.09(3)°, β = 99.46(3)°, γ= 111.87(3)°; 5 : space group P2₁/c (No. 14), Z = 4, a = 1804.0(5) pm, b = 2261.2(6) pm, c = 1830.1(7) pm, β = 96.99(3)°; 6 : space group P2₁/c (No. 14), Z = 4, a = 943.2(3) pm, b = 2510.6(7) pm, c = 1325.1(6) pm, β = 98.21(3)°).     

Three Bromides of Lanthanum: LaBr2, La2Br5, and LaBr3

Colourless LaBr₃ was obtained via the ammonium-bromide route and in singlecrystalline form by chemical vapour-phase transport with aluminium tribromide. Black single crystals of LaBr₂ and La₂Br₅ have been grown from the melts that are obtained by lithium reduction of lanthanum tribromide in sealed tantalum ampoules at 850°C. The crystal structures of the three bromides of lanthanum were refined: LaBr ₂. 2H₂–MoS₂ type, hexagonal (P6₃/mmc), a = 409.88(4) pm, c = 1390.0(1) pm, R = R_w = 0.092; La ₂ Br ₅. Pr₂I₅ type, monoclinic (P2₁/m), a = 789.09(6) pm, b = 424.89(4) pm, c = 1342.3(1) pm, β = 91.60(1)º, R = 0.067, R_w = 0.055; LaBr₃ . UCl₃ type, hexagonal (P6₃/m), a = 797.13(4) pm, c = 452.16(4) pm, R = 0.036, R_w = 0.032.     

Die Chloride Na3xM2–xCl6 (M = La?Sm) und NaM2Cl6 (M = Nd,Sm): Derivate des UCl3-Typs. Synthese,Kristallstruktur und Röntgenabsorptionsspektroskopie (XANES)

The Chlorides Na_3xM_2–xCl₆ (M = La? Sm) and NaM₂Cl₆ (M = Nd, Sm): Derivatives of the UCl₃-Type of Structure. Synthesis, Crystal Structure and X-Ray Absorption Spectroscopy (XANES) Single crystals of the derivatives of the UCl₃-type structure Na_3xM_2–xCl₆ (M = La/x = 0.364(4); Ce/0.349(5); Pr/0.318(8); Nd/0.305(5); Sm/0.246(4)) and NaSm₂Cl₆ were grown by different methods generally under reducing conditions. They are addition [Na(Sm₂)Cl₆] and addition/substitution variants [Na_2x(Na_xM_2–x)Cl₆] of the UCl₃ structure type [□(U₂)Cl₆]. X-Ray Absorption Spectroscopy (XANES) at the L_III edge characterizes NaSm₂Cl₆ and NaNd₂Cl₆ as mixed-valence compounds with valences of +2 and +3 in statistical distribution (approximately 1:1) for Sm and Nd, respectively.     

Platinum‐Indium Polyanions in the Structures of LaPtIn4 and LnPtIn3 (Ln = La,Ce, Pr,Nd, Sm) and Structure Refinement of Ce2Pt2In

The title compounds were prepared by reacting the elements in an arc‐melting furnace and subsequent annealing. The LaRuSn₃ type structure of the new compounds LnPtIn₃ (Ln = La, Ce, Pr, Nd, Sm) was refined from single crystal X‐ray data for LaPtIn₃: Pm3n, a = 980.4(2) pm, wR2 = 0.0271, 399 F² values, 15 variables. Striking structural motifs of LaPtIn₃ are condensed distorted trigonal [PtIn₆] prisms with Pt–In distances of 269 pm. The lanthanum atoms occupy large cavities within the polyhedral network. Besides Pt–In bonding In–In bonding also plays an important role in LaPtIn₃ with In–In distances of 299 and 327 pm. The La1 position is occupied only to 91%, resulting in a composition La_0.98(1)PtIn₃. The La1 atoms show an extremely large displacement parameter indicating a rattling of these atoms in the In₁₂ cages. The so far most indium rich compound in the ternary system lanthanum‐platinum‐indium is LaPtIn₄ which was characterized on the basis of Guinier powder data: YNiAl₄‐type, Cmcm, a = 455.1(2) pm, b = 1687.5(5) pm, and c = 738.3(2) pm. The platinum atoms in LaPtIn₄ center trigonal prisms with the composition [La₂In₄]. Together with the indium atoms the platinum atoms form a complex three‐dimensional [PtIn₄] polyanion in which the lanthanum atoms occupy large hexagonal tubes. The structure of Ce₂Pt₂In is confirmed: Mo₂FeB₂‐type, P4/mbm, a = 779.8(1) pm, c = 388.5(1) pm, wR2 = 0.0466, 433 F² values, 12 parameters. It is built up from CsCl and AlB₂ related slabs with the compositions CeIn and CePt₂, respectively. Chemical bonding in the [PtIn₃] and [PtIn₄] polyanions of LaPtIn₃ and LaPtIn₄ is discussed.     

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⁺.