Kristallstrukturen aus CaBe2Ge2‐ und CeMg2Si2‐analogen Blöcken: Die Phosphide LnPt2P2−x (Ln: La,Sm)

Crystal Structures of CaBe₂Ge₂ and CeMg₂Si₂ analogous Units: The Phosphides LnPt₂P_2?x (Ln: La, Sm) Single crystals of LaPt₂P_1.44 (a = 4.174(1), c = 19.212(5) Å) were grown by reaction of vaporous phosphorus with LaPt₂ at 1050 °C during two weeks, whereas SmPt₂P_1.50 (a = 4.131(1), c = 19.086(4) Å) was synthesized by heating mixtures of the elements at 900 and 1100 °C (60 h) and annealing at 1050 °C (300 h). Both phosphides were investigated by single crystal X‐ray methods. Their crystal structures (I4/mmm; Z = 4) consist of CaBe₂Ge₂ and CeMg₂Si₂ analogous units alternating with each other along [001]. The positions of the P1 atoms are occupied incompletely causing the deviation to the 1:2:2 stoichiometry. Another compounds LnPt₂P_2?x were studied by X‐ray powder diffraction resulting in the following lattice constants: a = 4.150(1), c = 19.132(5) Å for CePt₂P_2–x, a = 4.137(1), c = 19.085(4) Å for PrPt₂P_2?x, and a = 4.127(1), c = 19.040(2) Å for NdPt₂P_2?x.     

Synthese und Kristallstrukturen des Zink‐Rhodiumborids Zn5Rh8B4 und der Lithium‐ Magnesium‐Rhodiumboride LixMg5−xRh8B4 (x = 1.1 und 0.5) und Li8Mg4Rh19B12

Synthesis and Crystal Structures of Zinc Rhodium Boride Zn₅Rh₈B₄ and the Lithium Magnesium Rhodium Borides Li_xMg_5?xRh₈B₄ (x = 1.1 and 0.5) and Li₈Mg₄Rh₁₉B₁₂ The title compounds were prepared by reaction of the elemental components in metal ampoules under argon atmosphere (1100 °C, 7 d). In the case of Zn₅Rh₈B₄ (orthorhombic, space group Cmmm, a = 8.467(2) Å, b = 16.787(3) Å, c = 2.846(1) Å, Z = 2) a BN crucible enclosed in a sealed tantalum container was used. The syntheses of Li_xMg_5?xRh₈B₄ (orthorhombic, space group Cmmm, Z = 2, isotypic with Zn₅Rh₈B₄, lattice constants for x = 1.1: a = 8.511(3) Å, b = 16.588(6) Å, c = 2.885(1) Å, and for x = 0.5: a = 8.613(1) Å, b = 16.949(3) Å, c = 2.9139(2) Å) and Li₈Mg₄Rh₁₉B₁₂ (orthorhombic, space group Pbam, a = 26.210(5) Å, b = 13.612(4) Å, c = 2.8530(5) Å, Z = 2) were carried out in tantalum crucibles enclosed in steel containers using lithium as a metal flux. The crystal structures were solved from single crystal X‐ray diffraction data. In both structures Rh atoms reside at z = 0 and all non‐transition metal atoms at z = 1/2. Columns of Rh₆B trigonal prisms running along the c‐axis are laterally connected to form three‐dimensional networks with channels of various cross sections containing Li‐, Mg‐, and Zn‐atoms, respectively. A very short Li‐Li distance of 2.29(7) Å is observed in Li₈Mg₄Rh₁₉B₁₂.     

Neue Germanide mit geordneter Ce3Pt4Ge6‐Struktur – Die Verbindungen Ln3Pt4Ge6 (Ln: Pr–Dy)

New Germanides with an Ordered Variant of the Ce₃Pt₄Ge₆ Type of Structure – The Compounds Ln₃Pt₄Ge₆ (Ln: Pr–Dy) Six new germanides Ln₃Pt₄Ge₆ with Ln = Pr–Dy were synthesized by heating mixtures of the elements at 900 °C, annealing the inhomogeneous powders at 1050‐1100 °C for six days and then cooling down from 700 °C in the course of two months. The crystal structures of Pr₃Pt₄Ge₆ (a = 26.131(5), b = 4.399(1), c = 8.820(2) Å), Sm₃Pt₄Ge₆ (a = 25.974(3), b = 4.356(1), c = 8.748(1) Å), and Dy₃Pt₄Ge₆ (a = 26.079(5), b = 4.311(1), c = 8.729(2) Å) were determined by single crystal X‐ray methods. The compounds are isotypic (Pnma, Z = 4) and crystallize with an ordered variant of the Ce₃Pt₄Ge₆ type of structure (Cmcm, Z = 2) consisting of CaBe₂Ge₂‐ and YIrGe₂‐analogous units. The platinum atoms are located in distorted square pyramids of germanium atoms and build up with them a three‐dimensional network. The coordination polyhedra of the platinum and germanium atoms around the rare‐earth metal atoms are pentagonal and hexagonal prisms. These are completed by some additional atoms resulting in coordination numbers of 14 and 15 respectively. The other germanides were investigated by powder methods resulting in the following lattice constants: a = 26.067(6), b = 4.388(1), c = 8.800(2) Å for Ln = Nd; a = 25.955(7), b = 4.337(1), c = 8.728(2) Å for Ln = Gd; a = 25.944(5), b = 4.322(1), c = 8.698(2) Å for Ln = Tb. The atomic arrangement of Ln₃Pt₄Ge₆ is compared with the well‐known monoclinic structure of Y₃Pt₄Ge₆.     

One‐Dimensional Zinc Selenophosphates: A2ZnP2Se6 (A = K,Rb, Cs)

The new compounds A₂ZnP₂Se₆ (A = K, Rb, Cs) were synthesized via molten salt flux syntheses. The crystals feature one‐dimensional ¹/_∞[ZnP₂Se₆]^2– chains charge balanced by alkali metal ions between the chains. K₂ZnP₂Se₆ crystallizes in the monoclinic space group P2₁/c; cell parameters a = 12.537(3) Å, b = 7.2742(14) Å, c = 14.164(3) Å, β = 109.63(3)°, Z = 4, and V = 1216.7(4) ų. Rb₂ZnP₂Se₆ and Cs₂ZnP₂Se₆ are isotypic, crystallizing in the triclinic space group P$\bar{1}$ . Rb₂ZnP₂Se₆ has cell parameters of a = 7.4944(15) Å, b = 7.6013(15) Å, c = 12.729(3) Å, α = 96.57(3)°, β = 105.52(3)°, γ = 110.54(3)°, Z = 2, and V = 636.6(2) ų. Cs₂ZnP₂Se₆ has cell parameters of a = 7.6543(6) Å, b = 7.7006(6) Å, c = 12.7373(11) Å, α = 97.007(7)°, β = 104.335(7)°, γ = 109.241(6)°, Z = 2, and V = 669.54(10) ų.     

Metalloktaederdoppel in den Clusterverbindungen Gd10I16(C2)2 und Gd10Br15B2/Tb10Br15B2

Gd₁₀I₁₆(C₂)₂ and Gd₁₀Br₁₅B₂/Tb₁₀Br₁₅B₂ Cluster Compounds with M₁₀ Twin Octahedra The compound Gd₁₀I₁₆(C₂)₂ can be prepared from Gd metal, GdI₃ and C at 950 °C. It crystallizes in P1 with a = 10.463(4) Å, b = 16.945(6) Å, c = 11.220(4) Å, α = 99.15(3)°, β = 92.68(3)° und γ = 88.06(3)°. Gd₁₀Br₁₅B₂ is formed between 900 und 950 °C, Tb₁₀Br₁₅B₂ between 900 und 930 °C from stoichiometric amounts of the rare earth metals, tribromide and boron. Both compounds crystallize in the space group P1 for Gd₁₀Br₁₅B₂ with a = 8.984(2) Å, b = 9.816(2) Å, c = 10.552(5) Å, α = 91.14(3)°, β = 114.61(3)° and γ = 110.94(3)° and for Tb₁₀Br₁₅B₂ with a = 8.939(4) Å, b = 9.788(3) Å, c = 10.502(2) Å, α = 91.19(3)°, β = 114.51(3)° and γ = 111.10(2)°. In the crystal structures of all three compounds the rare earth metals form edge‐shared Ln₁₀ twin octahedra. In Gd₁₀I₁₆(C₂)₂ the Gd octahedra are centered with C₂ groups (d_C–C = 1.43(7) Å). In Ln₁₀Br₁₅B₂ (Ln = Gd, Tb) the octahedra contain single boron atoms. The clusters are connected through halide atoms to chains [Ln₁₀(Z)₂X X X ]. Adjacent chains are fused threedimensionally via I I for the Gd iodide carbide and via Br Br for the bromide borides of Gd und Tb. It is interesting to see an identical pattern of connection between the chains for the reduced oxomolybdates, e. g. PbMo₅O₈.     

Synthesis,Crystal Structure,and Vibrational Spectroscopy of the Alkali Diselenates A2Se2O7 (A = Li – Cs)

The reaction of alkali carbonates and selenium acid yielded the “pyroanions” [Se₂O₇]^2– containing alkali diselenates. By varying the alkali carbonates we were able to synthesize and determinate the crystal structures of the whole row from Li to Cs. Li₂Se₂O₇ crystallizes isotypic to Li₂S₂O₇ [Pnma, Z = 4, a = 13.815(3), b = 8.452(2) c = 5.0585(10) Å]. The structure of Na₂Se₂O₇ [P$\bar{1}$ , Z = 2, a = 6.9896(14), b = 6.9938(14), c = 7.0829(14) Å, α = 83.32(3), β = 64.56(3), γ = 83.18(3)°] is isotypic to Ag₂S₂O₇. A₂Se₂O₇ (A = K, Rb) [A = K: C2/c, Z = 4, a = 12.851(3), b = 7.5677(15), c = 7.5677(15) Å, β = 93.35(3)°; A = Rb: C2/c, Z = 4, a = 13.118(3), b = 7.7963(16), c = 7.7811(16) Å, β = 94.03(3)°] are isotypic to K₂S₂O₇. The crystal structure of Cs₂Se₂O₇ [P$\bar{1}$ , Z = 10, a = 7.7271(3), b = 16.2408(8), c = 18.4427(8) Å, α = 89.685(2), β = 89.193(2), γ = 76.251(2)°] seems to be isotypic to the averaged room‐temperature modification of Cs₂S₂O₇. With exception of the caesium compound all diselenate anions show an ecliptic arrangement and can be therefore classified as dichromate‐like structures. In Cs₂Se₂O₇ most of the [Se₂O₇]^2– units have a staggered alignment. The transition between both orientations can be explained by the increase of the cations size. Additionally the vibrational spectra of A₂Se₂O₇ with A = Li – Cs are discussed as well as the resulting bond forces.     

Mixed Valence Tungsten(IV,V) Compounds with Layered Structures (Part II)): Synthesis and Crystal Structures of Cu1−x[W2O2Cl6] and Cu1−x[W4O4Cl10]

The reaction of CuCl with WOCl₃ at 400 °C leads to a mixture of Cu_1?x[W₂O₂Cl₆] ( 1 ) and Cu_1?x[W₄O₄Cl₁₀] ( 2 ) in form of black lustrous needles. Both compounds crystallize in space group C2/m with a = 12.7832(5) Å, b = 3.7656(2) Å, c = 10.7362(3) Å, β = 119.169(2)° for 1 and a = 12.8367(19) Å, b = 3.7715(7) Å, c = 15.955(3) Å, β = 102.736(5)° for 2 . The structures are made up of WO₂Cl₄ octahedra. In the case of 1 two octahedra are edge‐sharing via chlorine atoms to form pairs which are linked via the trans‐positioned oxygen atoms to form infinite double strands . In the structure of 2 two of these double strands are condensed via terminal chlorine atoms to form quadruple strands . Like for all members of the M_x[W₂O₂X₆] structure family (X = Cl, Br) nonstochiometry with respect to the cations M was observed. The copper content of 1 and 2 was derived from the site occupation factors of the respective structure refinements. For several crystals examined the copper content varied between x = 0.27 and 0.17 for 1 and x = 0.04 for 2 . In both structures the oxochlorotungstate strands are negatively charged and connected to layers by the monovalent copper ions, which are tetrahedrally coordinated by the non‐bridging chlorine atoms of the strands. The structure models imply disorder of the Cu⁺ ions over closely neighboured sites.     

Synthesis,Crystal Structure,and Magnetic Properties of (2,2′‐dipyridylamine)(X−) Copper(II) Complexes (X−: Cyanate,Dicyanamide, Acetate,Thiocyanato)

The synthesis, structure, and magnetic properties of four 2,2′‐dipyridylamine ligand (abbreviated as Hdpa) containing copper(II) complexes. There is one binuclear compound, which is [Cu₂(μ_1,1‐NCO)₂(NCO)₂(Hdpa)₂] ( 1 ), and three mononuclear compounds, which are [Cu{N(CN)₂}₂(Hdpa)₂] ( 2 ), [Cu(CH₃CO₂)(Hdpa)₂·N(CN)₂] ( 3 ), and [Cu(NCS)(Acac)] ( 4 ). Compounds 1 and 4 crystallize in the monoclinic system, space group P2(1)/c and Z = 4, with a = 8.2465(6) Å, b = 9.3059(7) Å, c = 16.0817(12) Å, β = 91.090(1)°, and V = 1233.90(16) ų for 1 and a = 7.6766(6) Å, b = 21.888(3) Å, c = 10.4678(12) Å, β = 90.301(2)°, and V= 1758.8(4) ų for 4 . Compounds 2 and 3 crystallize in the triclinic system, space group P‐1 and Z = 1, with a = 8.1140(3) Å, b = 8.2470(3) Å, c = 9.3120(4) Å, β = 102.2370(10)°, and V = 592.63(4) ų for 2 and a = 7.4780(2) Å, b = 12.5700(3) Å, c = 13.0450(3) Å, β = 96.351(2)°, and V = 1211.17(5) ų for 3 . Complex ( 1 ), the magnetic data was fitted by the Bleaney‐Bowers equation (1). A very good fit was derived with J = 23.96, Θ = ?1.5 (g = 1.97). Complex ( 1 ) shows the ferromagnetism. Complexes ( 2 ), ( 3 ) and ( 4 ) of have the it is the typical paramagnetic behavior of unpaired electrons. Under a low temperature around 25 K, complexes ( 2 ) and ( 3 ) show weak ferromagnetic behavior. They are the cause of hydrogen bonds.     

Synthesis of the One-dimensional Compound (Ph4P)[In(P2Se6)] in a Ph4P+-Containing Selenophosphate Flux,and Structure of [In(P2Se6)2]5– – a Discrete Molecular Fragment of the [In(P2Se6)]nn– Chain

The reaction of one equivalent of In with a molten flux of (Ph₄P)₂Se₅ and P₂Se₅ (1 : 2), at 250 °C gave the (Ph₄P)[In(P₂Se₆)] ( I ). Stoichiometric elemental synthesis at 750 °C produced the Cs₅In(P₂Se₆)₂ ( II ). The thin, yellow crystals of ( I ), and the irregular, dark orange crystals of ( II ), appear to be air- and water-stable. Compound ( I ) crystallizes in the monoclinic space group C2/c (no. 15) and at 23 °C: a = 23.127(7) Å, b = 6.564(1) Å, c = 19.083(3) Å, β = 97.42(2)°, V = 2873(1) ų, Z = 4, final R/R_w = 4.4/5.2%. Compound ( II ) crystallizes in the tetragonal space group P4₂/m (no. 84) and at 23 °C: a = b = 13.886(1) Å, c = 7.597(2) Å, V = 1464.9(3) ų, Z = 2, final R/R_w = 3.9/5.1%. Compound ( I ) contains infinite [In(P₂Se₆)]_n^n– with a structure related to that of K₂FeP₂Se₆. Compound ( II ) contains the discrete [In(P₂Se₆)₂]^5– which can be viewed as a fragment of the [In(P₂Se₆)]_n^n– chain.     

Variationen modulo 4–4+, 4+3–3+4–, 4–5+, 5–4+4–5+4–4+ bei Seltenerdcarbidhalogeniden

The new compounds Pr₈(C₂)₄Cl₅ (1), Pr₁₄(C₂)₇Cl₉ (2), Pr₂₂(C₂)₁₁Cl₁₄ (3), Ce₂(C₂)Cl (4), La₂(C₂)Br (5), Ce₂(C₂)Br (6), Pr₂(C₂)Br (7), Ce₁₈(C₂)₉Cl₁₁ (8), and Ce₂₆(C₂)₁₃Cl₁₆ (9) were prepared by heating mixtures of LnX₃, Ln and carbon or in an alternatively way LnX₃, and “Ln₂C_3–x” in appropriate amounts for several days between 750 and 1200 °C. The crystal structures were investigated by X‐ray powder analysis (5–7) and/or single crystal diffraction (1–4, 8, 9). Pr₈(C₂)₄Cl₅ crystallizes in space group P2₁/c with the lattice parameters a = 7.6169(12), b = 16.689(2), c = 6.7688(2) Å, β = 103.94(1) °, Pr₁₄(C₂)₇Cl₉ in Pc with a = 7.6134(15), b = 29.432(6), c = 6.7705(14) Å, β = 104.00(3) °, Pr₂₂(C₂)₁₁Cl₁₄ in P2₁/c with a = 7.612(2), b = 46.127(9), c = 6.761(1) Å, β = 103.92(3) °, Ce₂(C₂)₂Cl in C2/c with a = 14.573(3), b = 4.129(1), c = 6.696(1) Å, β = 101.37(3) °, La₂(C₂)₂Br in C2/c with a = 15.313(5), b = 4.193(2), c = 6.842(2) Å, β = 100.53(3) °, Ce₂(C₂)₂Br in C2/c with a = 15.120(3), b = 4.179(1), c = 6.743(2) Å, β = 101.09(3) °, Pr₂(C₂)₂Br in C2/c with a = 15.054(5), b = 4.139(1), c = 6.713(3) Å, β = 101.08(3) °, Ce₁₈(C₂)₉Cl₁₁ in P$\bar{1}$ with a = 6.7705(14), b = 7.6573(15), c = 18.980(4) Å,α = 88.90(3) °, β = 80.32(3) °, γ = 76.09(3) °, and Ce₂₆(C₂)₁₃Cl₁₆ in P2₁/c with a = 7.6644(15), b = 54.249(11), c = 6.7956(14) Å, β = 103.98(3) ° The crystal structures are composed of Ln octahedra centered by C₂ dumbbells. Such Ln₆(C₂)‐octahedra are condensed into chains which are joined into undulated sheets. In compounds 1–4 three and four up and down inclined ribbons alternate (4₊4_–, 4₊3_–3₊4_–, 4₊4_–3₊4_–4₊3_–), in compounds 8 and 9 four and five (4₊5_–, 5₊4_–4₊5_–4₊4_–), and in compounds 4–7 one, one ribbons (1₊1_–) are present. The Ln‐(C₂)‐Ln layers are separated by monolayers of X atoms.     

Pr10[Si10−xAlxO9+xN17−x]Cl with x ≈ 1 – an Oxonitridoaluminosilicate Chloride

The oxonitridoaluminosilicate chloride Pr₁₀[Si_10?xAl_xO_9+xN_17?x]Cl was obtained by the reaction of praseodymium metal, the respective chloride, AlN and Al(OH)₃ with “Si(NH)₂” in a radiofrequency furnace at temperatures around 1900 °C. The crystal structure was determined by single‐crystal X‐ray diffraction (Pbam, no. 55, Z = 2,a = 10.5973(8) Å, b = 11.1687(6) Å, c = 11.6179(7) Å, R1 = 0.0337). The sialon crystallizes isotypically to the oxonitridosilicate halides Ce₁₀[Si₁₀O₉N₁₇]Br, Nd₁₀[Si₁₀O₉N₁₇]Br and Nd₁₀[Si₁₀O₉N₁₇]Cl, which represent a new layered structure type. The structure refinement was performed utilizing an O/N‐distribution model according to Paulings rules, i.e. nitrogen was positioned on all bridging sites and mixed O/Noccupation was assumed on the terminal sites resulting in charge neutrality of the compounds. The Si and Al atoms were refined equally distributed on their three crystallographic sites, due to their poor distinguishability by X‐ray analysis. The tetrahedra layers of the structure consist of condensed [(Si,Al)N₂(O,N)₂] and [(Si,Al)N₃(O,N)] tetrahedra of Q² and Q³ type. The chemical composition of the compound was derived from electron probe micro analyses (EPMA).     

Gewellt und eben – La6(C2)‐Oktaederschichten in Lanthancarbidchloriden

Sheets of La₆(C₂) Octahedra in Lanthanum Carbide Chlorides – undulated and plane The reaction of Ln, LnCl₃ (Ln = La, Ce) and C yields the hitherto unknown compounds La₈(C₂)₄Cl₅, Ce₈(C₂)₄Cl₅, La₁₄(C₂)₇Cl₉, La₂₀(C₂)₁₀Cl₁₃, La₂₂(C₂)₁₁Cl₁₄, La₃₆(C₂)₁₈Cl₂₃ and La₂(C₂)Cl. The gold‐ resp. bronze‐coloured metallic compounds are sensitive to moisture. The reaction temperatures are 1030 °C, 1000 °C, 970 °C, 1020 °C, 1020 °C, 1080 °C and 1030 °C in the order of compounds given, which mostly crystallize in the monoclinic space group P2₁/c with a = 7.756(1) Å, b = 16.951(1) Å, c = 6.878(1) Å, β = 104.20(1)° (La₈(C₂)₄Cl₅), a = 7.669(2) Å, b = 16.784(3) Å, c = 6.798(1) Å, β = 104.05(1)° (Ce₈(C₂)₄Cl₅), a = 7.669(2) Å, b = 16.784(3) Å, c = 6.789(1) Å, β = 104.05(3)° (La₂₀(C₂)₁₀Cl₁₃), a = 7.770(2) Å, b = 47.038(9) Å, c = 6.901(1) Å, β = 104.28(3)° (La₂₂(C₂)₁₁Cl₁₄) and a = 7.764(2) Å, b = 77.055(15) Å, c = 6.897(1) Å, β = 104.26(3)° (La₃₆(C₂)₁₈Cl₂₃), respectively. La₁₄(C₂)₇Cl₉‐(II) crystallizes in Pc with a = 7.775(2) Å, b = 29.963(6) Å, c = 6.895(1) Å, β = 104.21(3)° and La₂(C₂)Cl in C2/c with a = 14.770(2) Å, b = 4.187(1) Å, c = 6.802(1) Å, β = 101.50(3)°. The crystal structures are composed of distorted C₂ centered La‐octahedra which are condensed into chains via common edges. Three and four such chains join into ribbons, and these are connected into undulated layers with Cl atoms between them. The variations of the structure principle are analyzed systematically.     

Physicochemical study of the Sb2Se3-Ho2Se3 system

The chemical interaction in the Sb₂Se₃-Ho₂Se₃ system was studied by physicochemical analysis methods (by differential thermal, X-ray powder diffraction, and microstructural analyses and also by density and microhardness measurements). The state diagram of the system was constructed. It was found that the Sb₂Se₃-Ho₂Se₃ section is a quasi-binary section of the Ho-Sb-Se ternary system. In the system, the compound HoSbSe₃ forms, which melts incongruently at 1050 K and crystallizes in the rhombic system at the unit cell parameters a = 11.855 Å, b = 11.316 Å, c = 4.139 Å, and Z = 4 in the space group Pbnm-D _2h ¹⁶ . The solubility of solid solutions based on Sb₂Se₃ at room temperature reaches 8 mol % Ho₂Se₃, whereas solid solutions based on Ho₂Se₃ were not detected.     

Seltenerdhalogenide Ln4X5Z. Teil 1: C und/oder C2 in Ln4X5Z

Rare Earth Halides Ln₄X₅Z. Part 1: C and/or C₂ in Ln₄X₅Z The compounds Ln₄X₅C_n (Ln = La, Ce, Pr; X = Br, I and 1.0 < n < 2.0) are prepared by the reaction of LnX₃, Ln metal and graphite in sealed Ta‐ampoules at temperatures 850 °C < T < 1050 °C. They crystallize in the monoclinic space group C2/m. La₄I₅C_1.5: a = 19.849(4) Å, b = 4.1410(8) Å, c = 8.956(2) Å, β = 103.86(3)°, La₄I₅C_2.0: a = 19.907(4) Å, b = 4.1482(8) Å, c = 8.963(2) Å, β = 104.36(3)°, Ce₄Br₅C_1.0: a = 18.306(5) Å, b = 3.9735(6) Å, c = 8.378(2) Å, β=104.91(2)°, Ce₄Br₅C_1.5: a = 18.996(2) Å, b = 3.9310(3) Å, c = 8.282(7) Å, β = 106.74(1)°, Pr₄Br₅C_1.3: a = 18.467(2) Å, b = 3.911(1) Å, c = 8.258(7) Å, β = 105.25(1)° and Pr₄Br₅C_1.5: a = 19.044(2) Å, b = 3.9368(1) Å, c = 8.254(7) Å, β = 106.48(1)°. In the crystal structure the lanthanide metals are connected to Ln₆‐octahedra centered by carbon atoms or C₂‐groups. The Ln₆‐octahedra are condensed via opposite edges to chains and surrounded by X atoms which interconnect the chains. A part n of isolated C‐atoms is substituted by 1‐n C₂‐groups. The C‐C distances range between 1.26 and 1.40Å. In the ionic formulation (Ln³⁺)₄(X^?)₅(C^4?)_n(C₂^m?)_1?n·e^? with 0 < n < 1 and m = 2, 4, 6 (C₂^2?, C₂^4? C₂^6?), there are 1 < e^? < 5 electrons centered in metal‐metal bonds.     

Synthese und Kristallstrukturen von DyPt8P2 und Mg10−xPt9P7

Synthesis and Crystal Structures of DyPt₈P₂ and Mg_10?xPt₉P₇ Single crystals of DyPt₈P₂ (a = 9.260(2), b = 4.005(1), c = 9.633(2) Å, β = 102.64(3)°) were grown by heating the elements in a melt of NaCl/KCl at 1100 °C. The phosphide crystallizes in a new type of structure (I2/m; Z = 2) which consists of fragments in the shape of a cubic close packing built up by three fourths of the platinum atoms. The Dy atoms are coordinated by twelve Pt and four P atoms forming a distorted hexagonal prism which is fourfold capped by Pt atoms. Needles of Mg_10?xPt₉P₇ (a = 18.121(4), b = 23.316(5), c = 3.848(1) Å) were obtained by reaction of the elements in molten lead at 1000 °C. The main feature of the new type of structure (Pbam; Z = 4) is an oval ring of pentagonal prisms formed by each six Pt and four P atoms. The prisms are linked with each other via common faces and they are centered by Mg atoms. Another Mg atoms are located in holes of the three‐dimensional [Pt₉P₇] network. It is remarkable, that one of the ten different crystallographic sites of the Mg atoms is occupied incompletely inducing the composition Mg_10?xPt₉P₇ with x = 0.86.     

Li6+2x[B10Se18]Sex (x ≈ 2), ein ionenleitendes Doppelsalz

Li_6+2x[B₁₀Se₁₈]Se_x (x ≈ 2), an Ion‐conducting Double Salt Li_6+2x[B₁₀Se₁₈]Se_x (x ≈ 2) was prepared in a solid state reaction from lithium selenide, amorphous boron and selenium in evacuated carbon coated silica tubes at a temperature of 800 °C. Subsequent cooling from 600 °C to 300 °C gave amber colored crystals with the following lattice parameters: space group I2/a (at 173 K); a = 17.411(1) Å, b = 21.900(1) Å, c = 17.820(1) Å, β = 101.6(1)°. The crystal structure contains a well‐defined polymeric selenoborate network of composition ([B₁₀Se₁₆Se_4/2]^6?)_n consisting of a system of edge‐sharing [B₁₀Se₁₆Se_4/2] adamantanoid macro‐tetrahedra forming large channels in which a strongly disorderd system of partial occupied Li⁺ cations and additional disordered Se^2? anions is observed. The crystal structure of the novel selenoborate is isotypic to Li_6+2x[B₁₀S₁₈]S_x (x ≈ 2) [1]. X‐ray and ⁷Li magic‐angle spinning NMR data suggest that the site occupancies of the three crystallographically distinct lithium ions exhibit a significant temperature dependence. The lithium ion mobility has been characterized by detailed temperature dependent NMR lineshape and spin‐lattice relaxation measurements.     

Synthesis of New LnxBi2–xSe3 (Ln: Sm3+, Eu3+, Gd3+, Tb3+) Nanomaterials and Investigation of Their Optical Properties

New Ln_xBi_2–xSe₃ (Ln: Sm³⁺, Eu³⁺, Gd³⁺, Tb³⁺) based nanomaterials were synthesized by a co‐reduction method. Powder XRD patterns indicate that the Ln_xBi_2–xSe₃ crystals (Ln = Sm³⁺, Eu³⁺, x = 0.00–0.44 and Ln = Gd³⁺, Tb³⁺, x = 0.00–0.50) are isostructural with Bi₂Se₃. The cell parameter c decreases for Ln = Eu³⁺, Gd³⁺, Tb³⁺ upon increasing the dopant content (x), while a slightly increases. Changes in lattice parameters could be related to the radii of cations. SEM images show that doping of the lanthanide ions in the lattice of Bi₂Se₃ generally results in nanoflowers. For the terbium compound two kinds of morphologies (nanoflowers and nanobelts) were observed. UV/Vis absorption and emission spectroscopy reveals mainly electronic transitions of the Ln³⁺ ions. Emission spectra show intense transitions from the excited to the ground state of Ln³⁺ and energy transfer from the Bi₂Se₃ lattice. Emission spectra of europium‐doped materials, in addition to the characteristic red emission peaks of Eu³⁺, show an intense blue emission band centered at 432 nm, originating from the 4f⁶5d¹ to 4f⁷ configuration in Eu²⁺. EPR measurements confirm the existence of Eu²⁺ in the materials. Interestingly, for all samples starting at low Ln³⁺ concentration, the emission intensity rises to a maximum at a Ln³⁺ concentration of x = 0.2 and falls again steadily to a minimum at x = 0.45.     

LaS1.9, CeS1.9, PrS1.9, NdS1.9 und GdS1.9: Fünf neue Lanthanoidpolysulfide – Synthese und Kristallstrukturen und ihre Strukturbeziehung zum ZrSSi‐Typ

LaS_1.9, CeS_1.9, PrS_1.9, NdS_1.9, and GdS_1.9: Five new Lanthanide Polysulfides – Syntheses, Crystal Structures and their Structural Relationship to the ZrSSi Type Crystals of the five new lanthanide polysulfides LaS_1.9, CeS_1.9, PrS_1.9, NdS_1.9, and GdS_1.9 have been prepared by different synthetic routes. According to X‐ray structure analyses, the compounds adopt the tetragonal CeSe_1.9 type structure (space group: P4₂/n, no. 86) with the lattice parameters a = 9.111(1) Å, c = 16.336(2) Å (LaS_1.9), a = 9.015(3) Å, c = 16.168(4) Å (CeS_1.9), a = 8.947(3) Å, c = 16.054(4) Å (PrS_1.9), a = 8.901(3) Å, c = 16.022(4) Å (NdS_1.9), and a = 8.714(1) Å, c = 15.791(1) Å (GdS_1.9), respectively. The crystal structure consists of puckered [LnS] double slabs and planar sulfur layers alternating along [001]. Each planar sulfur layer contains disulfide dumbbells, isolated anions and ordered vacancies.     

[NaSn12O8Se6]3— — ein Chalkogenostannatanion mit schalenförmigem Aufbau

[NaSn₁₂O₈Se₆]^3— — a Chalcogenostannate Anion with Shell Structure In the anion of (Et₄N)₃[NaSn₁₂O₈Se₆] · DMF ( 1 · DMF) the central sodium atom is surrounded by a cube of O atoms, a Sn₁₂ cuboctahedron and an Se₆ octahedron with increasing size. 1 · DMF crystallizes in space group P2₁/c with a = 1904.6(1), b = 2266.9(1), c = 1390.35(8) pm, β = 104.538(5)°, Z = 4.     

Pure trinuclear 4f single-molecule magnets: synthesis, structures, magnetism and ab initio investigation

A family of linear Dy₃ and Tb₃ clusters have been facilely synthesized from the reactions of DyCl₃, the polydentate 3‐methyloxysalicylaldoxime (MeOsaloxH₂) ligand with auxiliary monoanionic ligands, such as trichloroacetate, NO₃^?, OH^?, and Cl^?. Complexes 1 – 5 contain a nearly linear Ln₃ core, with similar Ln???Ln distances (3.6901(4)–3.7304(3) Å for the Dy₃ species, and 3.7273(3)–3.7485(5) Å for the Tb₃ species) and Ln???Ln???Ln angles of 157.036(8)–159.026(15)° for the Dy₃ species and 157.156(8)–160.926(15)° for the Tb₃ species. All three Ln centers are bridged by the two doubly‐deprotonated [MeOsalox]^2? ligands and two of the four [MeOsaloxH]^? ligands through the N,O‐η²‐oximato groups and the phenoxo oxygen atoms (Dy‐O‐Dy angles=102.28(16)–106.85(13)°; Tb‐O‐Tb angles=102.00(11)–106.62(11)°). The remaining two [MeOsaloxH]^? ligands each chelate an outer Ln^III center through their phenoxo oxygen and oxime nitrogen atoms. Magnetic studies reveal that both Dy₃ and Tb₃ clusters exhibit significant ferromagnetic interactions and that the Dy₃ species behave as single‐molecule magnets, expanding upon the recent reports of the pure 4f type SMMs.