3s-Gd2C2Br2: Eine neue Stapelvariante

3s-Gd₂C₂Br₂: An Isomorph with a New Stacking Sequence Gd₂C₂Br₂ has been described in [1]. Here we describe the new stacking variant 3s-Gd₂C₂Br₂ prepared by reaction of stoichiometric amounts of GdBr₃, Gd, and C at 1 320 K. 3s-Gd₂C₂Br₂ with a stacking sequence different to that described in [1] crystallizes in space group C2/m with lattice constants a = 706.6(2) pm, b = 382.7(1) pm, c = 996.7(4) pm and β = 99.95(3)°. In the structure C₂ units are octahedrally surrounded by Gd atoms. Such Gd₆(C₂) octahedra are condensed via edges to form sheets, which are separated by two layers of Br-ions. In contrast to the modification described previously three slabs BrGd(C₂)GdBr are stacked in [103] direction until identity is reached. The isotypic 3s-Tb₂C₂Br₂ has also been prepared at 1 370 K. It is characterized by the lattice constants a = 701.5(3) pm, b = 380.1(1) pm, c = 994.8(3) pm and β = 100.05°.     

Chemical Intergrowth in Gadolinium Carbide Chloride – a HRTEM Study

An investigation on the real structure of Gd₆Cl₅C₃ has been carried out by means of high-resolution electron microscopy. The occurence of lamellar defects is interpreted as chemical intergrowth of the two closely related phases Gd₆Cl₅C₃ and Gd₂Cl₂C. Loading of the samples, which are very sensitive to air and moisture, and the insertion of the sample holder into the microscope has been realised using a specially designed transfer system.     

Struktur und Eigenschaften von Gd3I3C

Structure and Properties of Gd₃I₃C . The compound Gd₃I₃C is prepared by reaction of Gd, GdI₃ and C (2:1:1 mole) at 1 250 K in sealed Ta tubes. It is obtained as bronze-coloured needles which are air and moisture sensitive. The structure of Gd₃I₃C contains twin chains of C centered Gd₆ octahedra surrounded by I atoms capping all free edges like in the M₆X₁₂ cluster. The one-dimensional units are oriented along [010] and linked according to (GdGd_1/3Gd_2/2Gd_2/3C)₂IIII. Gd₃I₃C is metallic in the temperature range 300 K ≥ T ≥ 120 K, between 120 and 15 K the electrical resistance increases by 6 orders of magnitude. At high temperatures the susceptibility follows the Curie-Weiß law with a paramagnetic Curie temperature θ ≈ - 340 K. Two local maxima in the susceptibility at 100 K and 25 K indicate successive formation of antiferromagnetically ordered structures.     

Synthese,Kristallstruktur und magnetisches Verhalten von Gd(CF3CF2COO)3(H2O)3

Synthesis, Crystal Structure and Magnetic Behaviour of Gd(CF₃CF₂COO)₃(H₂O)₃ Single crystals of Gd(CF₃CF₂COO)₃(H₂O)₃ have been obtained by reaction of Gd₂O₃ with an aqueous solution of CF₃CF₂COOH. The compound crystallizes triclinically in the space group (No. 2; Z = 2; a = 928.5(1) pm, b = 1037.1(1) pm, c = 1147.3(2) pm, α = 90.44(2)°, β = 108.56(1)°, γ = 106.49(1)°). In the crystal structure the gadolinium ions are bridged by carboxylate groups to dimers and are coordinated eightfold by oxygen atoms. The magnetic behaviour was investigated in the temperature range of 1.77 to 300 K. The magnetic data indicate weak antiferromagnetic interactions within the dimeric unit (J_ex = ?0.0057 cm^?1).     

Das erste Alkali-Erdalkalimetall-Oxo/Peroxo-Aurat(III): NaBa4AuO4(O2)2

On the first Alkaline-Alkaline-Earth-Oxo/Peroxo-Aurate(III): NaBa₄AuO₄(O₂)₂ The hitherto unknown compound NaBa₄AuO₄(O₂)₂ was prepared by oxidizing of barium gold alloy with Na₂O₂ in closed Ag-bombs. X-ray single crystal investigation led to tetragonal symmetry space group DI4/mmm, a = 5.939; c = 15.393 Å, Z = 2. NaBa₄AuO₄(O₂)₂ shows a distorted square antiprismatic surrounding of Ba²⁺ by four peroxo groups on one side and four O^2? on the opposite. Au³⁺ shows the usual square planar polygons of AuO₄. Na⁺ is coordinated by four O^2? ions in the base of an octahedron and two peroxo groups in the apical positions.     

Li2Br(NH2): Das erste ternäre Alkalimetallamidhalogenid

Li₂Br(NH₂): The First Ternary Alkali Metal Amide Halide The pseudobinary system LiNH₂/LiBr was investigated by X-ray methods. The crystal structure of the compound Li₂Br(NH₂) was solved by single crystal data: Li₂Br(NH₂): Pnma, Z = 8, a = 12.484(2) Å, b = 7.959(1) Å, c = 6.385(1) Å, Z(F_o) with (F_o)² ≧ 3σ(F_o)² = 348, Z (parameter) = 51, R/R_w = 0.019/0.021 Li₂Br(NH₂) crystallizes in a new type of structure. To one another isolated chains of [Li₂Li_4/2(NH₂)₂²⁺] show the motif of closest rod packing. They are connected via bromide ions in a distorted cubic primitive arrangement.     

[Gd4(C2)](Cl,I)6, an Interstitially Stabilized Heteroleptic Gadolinium Sesquihalide

[Gd₄(C₂)](Cl, I)₆ is obtained from CsI, Gd, GdCl₃ and C₂I₄ in sealed niobium containers at 1000/800°C as black, shiny needles. The crystal structure (tetragonal, P4/mbm, Z = 2, a = 1347.5(1), c = 1212.5(1) pm) is similar to that of Na[Mo₄]O₆ and [Sc₄B]Cl₆. It may be regarded as being built from octahedra sharing common trans edges running in the [001] direction. The octahedra contain C₂ units as interstitials. Every third octahedron contains a disordered C₂ unit perpendicular to those in the two neighboring [Gd₆(C₂)] octahedra and is therefore compressed in the direction of the (pseudo) C₄ axis. Calculations of the electronic structure of an “empty” [Gd₄]Cl₆ structure reveals a total of 13 electrons necessary to occupy all metal-metal bonding states. The incorporation of a carbon dimer substantially alters the bonding conditions for [Gd₄(C₂)]X₆ (X = Cl, I). The formal charge of ?6 of the C₂ unit is significantly reduced as π_g states split up, Gd? Gd and Gd? C bonding states are occupied and bonding d orbitals combine to form the lowest unoccupied energy states.     

Das erste Alkali-Erdalkalimetall-Oxoniccolat(II,III): NaBa2Ni22+Ni3+O6

The First Alkalinc Alkaline Earth Oxoniccolate(II,III): NaBa₂Ni₂²⁺Ni³⁺O₆ Single crystals of NaBa₂Ni₂²⁺Ni³⁺O₆ were prepared by solid state reaction. X-ray investigations led to orthorhombic symmetry, space group D-Fmmm; a = 8.310; b = 11.220; c = 14.397 Å; Z = 8. Na⁺ is coordinated by six O^2? in form of a trigonal prism and the two Ba²⁺ point positions show different coordination numbers C.N. = 6 + 4 and 8. The Ni²⁺ /Ni³⁺ ions are in square planar polygons, six of them are forming a so far unknown closed macro polyhedra.     

Das erste Alkali-Erdalkali-Oxocuprat(II,III): NaBa2Cu22+Cu3+O6

The first Alkaline Alkaline-Earth Oxocuprate (II, III): NaBa₂Cu₂²⁺Cu³⁺O₆ The compound NaBa₂Cu₃O₆ was prepared by heating of Na₂O₂, BaO₂, Cu₂O in closed Ag-tubes. X-ray single crystal investigations led to orthorhombic symmetry, space group D-Fmmm; a = 8.4229; b = 11.4418; c = 14.4063 Å; Z = 8. Cu²⁺ and Cu³⁺ show square planar polygones of four and Na⁺ trigonal prisms of six O^2?. The two barium point positions show coordination numbers C.N. = 8 and 6 + 4. The crystal structure is discussed.     

Die Gadoliniumcarbidhalogenide Gd4C2X3 (X = Cl,Br)

The Gadolinium Carbide Halides, Gd₄C₂X₃ (X = Cl, Br) The compounds Gd₄C₂X₃ (X = Cl, Br) and Tb₄C₂Br₃ have been prepared by reaction of the metals (RE), REX₃, and C in sealed Ta capsules at 1 100° and 1 300°C, respectively. Monophasic samples of Gd₄C₂Br₃ and Tb₄C₂Br₃ were obtained by reacting stoichiometric mixtures of the starting materials for five days. The needle shaped crystals are bronze-coloured and sensitive to air and moisture. Gd₄C₂X₃ crystallizes in the space group Pnma (No. 62) with lattice constants a = 1 059.6(4), b = 368.4(1), c = 1 962.7(8) pm (Gd₄C₂Cl₃), a = 1 084.4(1), b = 373.0(1), c = 2 036.1(1) pm (Gd₄C₂Br₃). According to Guinier photographs, Tb₄C₂Br₃ is isotypic (a = 1 074.3(2), b = 370.6(1), c = 2 019.4(1) pm). In the crystal structure C is octahedrally coordinated by Gd. The Gd₆ octahedra are linked via common edges to form corrugated layers. The X-anions coordinate all free edges and corners of these layers and connect them via Xⁱ? Xⁱ contacts parallel [001]. Gd₄C₂Br₃ shows metallic conductivity. The magnetic susceptibility follows at high temperatures a Curie Weiss law with an effective moment of 7.95 μ_B. At temperatures below 50 K antiferromagnetic order is observed.     

Ba5[CrN4]N: Das erste Nitridochromat(V)

Ba₅[CrN₄]N: The First Nitridochromate(V) Ba₅[CrN₄]N is prepared by reaction of mixtures of Li₃N, Ba₃N₂ and CrN/Cr₂N (1 : 1) (molar ratio Li : Ba : Cr = 3 : 5 : 1) in tantalum crucibles at 700°C with flowing nitrogen (1 atm) within a period of 48 h. After cooling down to room temperature (60°C/h) black-shining single crystals of the ternary phase with a platy habit are obtained (monoclinic, C2/m; a = 1054.0(2) pm, b = 1170.9(3) pm, c = 937.7(2) pm, b? = 110,79(2)°; Z = 4). The crystal structure contains isolated complex anions [Cr^VN₄]^7? which nearly satisfy the ideal tetrahedral symmetry (Cr? N [pm]: 2 × 175.3(4), 2 × 175.8(5); N? Cr? N [°]: 106.8(2), 109.5(2), 2 × 109.9(2), 2 × 110,3(2)). The coordination sphere for each of the terminal nitride functions of the complex anions is completed by five neighbouring Ba²⁺ ions (distorted CrBa₅ octahedra). The octahedra are connected via common CrBa₂ faces as well as CrBa edges thereby forming condensed tetrameric octahedral groups. The isolated nitride ions which are also present in the crystal structure of Ba₅[CrN₄]N are in an octahedral environment of Ba²⁺ ions. The presence of a d¹-System (Cr(V)) is confirmed by magnetic susceptibility data.     

[La2Cl3(OAc)2(H2O)7]Cl: Das erste Lanthanid-Acetat-Halogenid-Hydrat mit Chlorid in innerer Koordinationssphäre

[La₂Cl₃(OAc)₂(H₂O)₇]Cl: The First Lanthanide-Acetate-Halide-Hydrate with Chloride in Inner-Sphere Coordination [La₂Cl₃(OAc)₂(H₂O)₇]Cl has been obtained as single crystals through the reaction of LaCl₃ · 7H₂O with diluted acetic acid or from La₂O₃ with acetyl chloride. In the crystal structure (triclinic, Z = 2, P1 (no. 2), a = 919.6(2), b = 950.7(2), c = 1178.9(2) pm, α = 82.52(1), β = 84.14(1), γ = 64.69(1)°, R = 0.021, R_w = 0.020), La³⁺ is surrounded by nine ligands (O, Cl). La1 has two chloride and seven oxygen ligands whereas La2 has one chloride and eight oxygen atoms as nearest neighbours. Four of the oxygen ligands of each lanthanum cation originate from a ?tetradentate”? acetate anion, the others from crystal water molecules. The ?tetradentate”? acetate groups are coordinated not only to one central La³⁺ as chelate ligands, but also to the ?left”? and ?right”? La³⁺ neighbours. Thereby, a one-dimensional infinite cationic chain, [La₂Cl₃(OAc)₂(H₂O)₇]⁺, is formed that runs in the [011] direction. These chains are held together by ?lonesome”? chloride ions which are surrounded by (4 + 1) water molecules and connected to the chains via hydrogen bonds.     

The New Carbodiimide Li2Gd2Sr(CN2)5 Having a Crystal Structure Related to That of Gd2(CN2)3

The new carbodiimide compounds Li₂RE₂Sr(CN₂)₅ (RE = Sm, Gd, Eu, Tb) were prepared by a straight forward solid state metathesis reaction of REF₃, SrF₂, and Li₂(CN₂) at around 600 °C. The crystal structure of Li₂Gd₂Sr(CN₂)₅ was solved based on X‐ray single‐crystal diffraction data. Corresponding Li₂RE₂Sr(CN₂)₅ compounds were analyzed by isotypic indexing of their powder patterns. The crystal structure of Li₂Gd₂Sr(CN₂)₅ can be well related to that of Gd₂(CN₂)₃, because both structures are based on layered structures composed of close packed layers of [N=C=N]^2– sticks, alternating with layers of metal ions. The crystal structure of Li₂Gd₂Sr(CN₂)₅ can be considered to contain an ABC layer sequence of [N = C=N]^2– layers with the interlayer voids being occupied by (three) distinct types of cations.     

Li2H4I2O10, das erste Tetrahydrogendimesoperiodat

Li₂H₄I₂O₁₀, the First Tetrahydrogendimesoperiodate Li₂H₄I₂O₁₀ has been obtained as an intermediate during the dehydration of LiH₄IO₆ · H₂O to LiIO₄, for the first time. According to the results of an X-ray structure determination (monoclinic, P2₁/n, a = 533.98(4), b = 471.85(4), c = 1431.48(10) pm, β = 91.614(7)°, Z = 2, 726 diffractometer data, R = 0.056), Li₂H₄I₂O₁₀ contains the previously unknown tetrahydrogendimesoperiodate ion H₄I₂O₁₀^2?, consisting of two edge-shared IO₆ octahedra. They are connected with LiO₆ octahedra via common edges and vertices. The crystals are non-merohedrally twinned along (100).     

TbFCl2: Das erste Fluoridchlorid der dreiwertigen Lanthanoide

TbFCl₂: The First Fluoride Chloride of the Trivalent Lanthanoids Single crystals of TbFCl₂ (monoclinic, C2/c; a = 890.28(5), b = 581.56(3), c = 683.37(4) pm, β = 109.621(4)°; Z = 4) can be obtained by the reaction of TbCl₃ and TbF₃ under inert‐gas atmosphere in tantalum capsules (900 °C, 10 d) as colourless transparent lath‐shaped blocks. The crystal structure contains only one singular Tb³⁺ cation which is eightfold coordinated by two F⁻ (d(Tb³⁺−F⁻) = 218 pm, 2×) and six Cl⁻ anions (d(Tb³⁺−Cl⁻) = 280−287 pm) forming a distorted square antiprism. The F⁻ anions are linear surrounded by two Tb³⁺ cations while the Cl⁻ anions reside in a quasi‐planar coordination of three Tb³⁺ cations, therefore the Niggli formula for TbFCl₂ has to be . Terbium and fluorine form zigzag chains along the c axis that are not connected to each other and arrange like a hexagonal rod‐packing. These cationic chains are mantled by Cl⁻ anions which take care for the charge balance and the three‐dimensional cross‐linkage. The structural relationship of TbFCl₂ with YF₃‐type and PuBr₃‐type will also be discussed.     

Über Ag2SnO3, das erste Silberstannat

On Ag₂SnO₃, the First Silver Stannate For the first time, crystals of red Ag₂SnO₃ have been obtained by solid state reaction of freshly prepared K₂Sn(OH)₆ and Ag₂O at 430°C while applying an oxygen pressure of 350 bar. Ag₂SnO₃ shows a one dimensional incommensurate superstructure with a′ = 33.1 Å. Here we report on the basic structure of Ag₂SnO₃. According to the results of X-ray crystal structure determination the basic structure of Ag₂SnO₃ may be described in P6₃22 (a = 5.6230(4) Å, c = 12.6694(14) Å, Z = 4, 968 independent reflections, R1 = 5.6%, wR2 = 12.5%). Within the layered “SnO₃” partial structure two third of the octahedral voids are occupied by tin. Those SnO₃ layers are connected to each other by almost linearly coordinated silver atoms. Additionally, silver occupies the free octahedral voids within the SnO₃ sheets. As expressed by the formula Ag[Ag_1/3Sn_2/3]O₂ the structure may be described as a super structure of Delafossite CuFeO₂.     

Neue Ergebnisse auf dem Gebiet der Komplexchemie der Lanthanoiden Die Strukturen von [(C11H21N2)2LnBr] (Ln = Sm,Gd)

New Results in the Chemistry of Lanthanoide Complexes. The Crystal Structures of [(C₁₁H₂₁N₂)₂LnBr] (Ln = Sm, Gd) LnBr₃ leads with [(ⁱPr₂AIP)Li] (AIP = 2-ⁱPropylamino-4-ⁱPropylimino-2-Pentene) to the mononuclear complex [(ⁱPr₂AIP)₂LnBr] (Ln = Gd 1 , Sm = 2 ). The structures of 1 – 2 were characterized by X-ray single crystal structure analysis.

• 1: Space group Cc, Z = 4, a = 1283.3(7) pm, b = 1558.6(8) pm, c = 1330.1(7) pm, β = 90.24(4)°
• 2: Space group Cc, Z = 4, a = 1281.7(2) pm, b = 1562.3(3) pm, c = 1329.8(2) pm, β = 90.09(1)°.

The Ln-Ion is coordinated by a Brom-Atom and the four Nitrogen-Atoms of the chelate ligand.     

Das erste quaternäre Oxocobaltat(I): CsK2[CoO2]

The First Quaternary Oxide of Monovalent Cobalt: CsK₂[CoO₂] Dark-red single crystals of CsK₂[CoO₂] were obtained via ?reaction with the cyliner surface”? by heating powders of Cs₂K₂Cd₃O₅ in closed Co-cylinders at 500°C during 48 d. Structure solution and refinement (four-circle diffractometer data, MoKα , 147 independent I_o(hkl), none was omitted, R = 3.42%, R_w = 2.24%) show close relationship with RbNa₂[NiO₂] [2]. The lattice-constants are: (powder data, standard deviations in parentheses) MAPLE calculations, investigations of magnetism and EPR measurement add to the monovalence of Co.     

Reaktion von Chlornitrat mit CF3I: Isolierung von Trifluormethylchloriodnitrat CF3I(Cl)ONO2 und Kristallstruktur von Trifluormethylioddinitrat CF3I(ONO2)2

Reaction of Chlorine Nitrate with CF₃I: Isolation of Trifluormethylchloroiodinenitrate CF₃I(Cl)ONO₂ and the Crystal Structure of Trifluormethyliodinedinitrate CF₃I(ONO₂)₂ CF₃I reacts with ClONO₂ to Iodine(III)-compounds. After an addition CF₃I(Cl)ONO₂ is isolated and characterized by vibrational spectra. With surplus ClONO₂ it is formed CF₃I(ONO₂)₂. CF₃I(ONO₂)₂ crystallizes monoclinic in the space group P2₁/c with the cell parameters a = 1 024.3(6) pm, b = 873.5(6) pm, c = 873.4(6) pm and Z = 4. We measered following bonding distances: I? O: 207.3(3) and 220.8(2) pm, I? C: 221.1(4) pm and N? O: from 119.1(4) to 141.5(3) pm. Through an intermolecular I ··· O-contact the central iodine becomes a distorted plane geometry.