Über die Synthese von Erdalkalimetalldihalogeniden und die Strukturen von Ca3Br2CBN und Sr3Cl2CBN

On the Synthesis of Alkaline-Earth Dihalides and the Structures of Ca₃Br₂CBN and Sr₃Cl₂CBN The reaction of alkaline-earth carbonates with ammonium chloride or bromide yields alkaline-earth dihalides at relatively low temperatures (300°C). Ca₃Br₂CBN and Sr₃Cl₂CBN were synthesized in sealed niobium containers at 950°C from the metal, its dihalide, boron nitride and graphite. The crystal structure of Sr₃Cl₂CBN was refined from single crystal data. Sr₃Cl₂CBN crystallizes isotypic with Ca₃Cl₂CBN in the orthorhombic space group Pnma (No. 62) with a = 1448.4(2) pm b = 405.46(5) pm, c = 1170.0(1) pm. The lattice constants of Ca₃Br₂CBN and Sr₃Cl₂CBN were determined by orthorhombic indexing of the powder patterns (Ca₃Br₂CBN: a = 1444.3(2) pm, b = 390.64(6) pm, c = 1139.2(2) pm; Sr₃Cl₂CBN: a = 1444.0(4) pm, b = 405.27(8) pm, c = 1167.8(2) pm). There was no success in preparing homologues with Barium.     

Tl4Pd3Cl10 – eine Verbindung mit neuartiger [(PdCl2Cl2/2)4]4–‐Baugruppe

Tl₄Pd₃Cl₁₀ – A Compound with a New [(PdCl₂Cl_2/2)₄]^4– Group Single crystals of Tl₄Pd₃Cl₁₀ can be obtained by hydrothermal synthesis. They show tetragonal symmetry with lattice parameters a = 15.956(1) Å and c = 14.146(1) Å, Z = 8 and space group I42d (No. 122). The atomic arrangement of Tl₄Pd₃Cl₁₀ is explored by X‐ray crystal structure analysis. Tl₄Pd₃Cl₁₀ is the first example of a new structural type with a hitherto not isolated tetramer [(PdCl₂Cl_2/2)₄]^4– group.     

Pentacalciumhexaphosphahypodiphosphat,Ca5P8: Eine Verbindung mit isolierten Anionen P810− mit der gestaffelten Konformation von Ethan

Pentacalcium Hexaphosphahypodiphosphate, Ca₅P₈, a Compound with Isolated Anions P₈^10? in the Staggered Ethane Conformation Ca₅P₈ is prepared from calcium and red phosphorus in a molar ratio 5:8 in argon atmosphere in corundum crucibles inserted in quartz ampullae (3.5 d 1 000°C). It is a red-brown powder which is hydrolyzed by moisture. Single crystals are formed from powder at 1 100°C within 60 d. Ca₅P₈ crystallizes in a new structure type (mC26) with isolated anions P₈^10? in staggered conformation: C2/m (no. 12); a = 689.9(4) pm, b = 1 188,3(4) pm, c = 748.4(3) pm, β = 108.25(2)°, Z = 2; d = 2.56(1). Ca₅P₈ is the first compound containing polyphosphide anions with fourfold and single bonded phosphorus atoms (formally P⁺ and P^2?, resp.). The cations Ca²⁺ are arranged in a distorted cubic close-packing. The centers of the polyphosphide anions replace in an ordered way one third of Ca²⁺ in every second layer. The terminal P atoms occupy all octahedral interstices, so that P₈^10? is coordinated by 18 Ca²⁺ in form of a cuboctahedron with capped squaric faces.     

CsPdCl3 – eine Verbindung mit [Pd2Cl6]-Baugruppen und anorganischem Kation

CsPdCl₃ – A Compound with Isolated [Pd₂Cl₆] Groups and an Inorganic Cation The crystal structure of CsPdCl₃ has been characterized by X-ray powder diffraction methods. Meanwhile it was possible to isolate single crystals and to confirm the structure by single crystal X-ray investigations. CsPdCl₃ crystallizes orthorhombic in space group Ibam (No. 72) with a = 13.724(1), b = 10.579(1), c = 8.499(1) Å, and Z = 8. CsPdCl₃ is a compound with a dinuclear [Pd₂Cl₆]^2– group and a cesium cation. Formerly such groups are only found in combination with large “organic” cations so far.     

AlCl3 · 2NH3 – eine Verbindung mit der Kristallstruktur eines Tetraammindichloroaluminium-tetrachloroaluminats – [AlCl2(NH3)4]+[AlCl4]−

ACl₃ · 2NH₃ – a Compound with the Crystal Structure of a Tetraammine Dichloroaluminiumtetrachloroaluminate – [AlCl₂(NH₃)₄]⁺[AlCl₄]^? Ammoniates of aluminiumchloride AlCl₃ · xNH₃ are in discussion as starting materials for the synthesis of aluminiumnitride. Therefore the reactions of melts of monoamminealuminiumchloride with ammonia were investigated. They react at 150°C within 10 min with one mole of ammonia to the diammoniate, [AlCl₂(NH₃)₄]⁺[AlCl₄]^?. The pure compound can be obtained by sublimation at 200°C in vacuumline apparatus. X-ray structure determination on [AlCl₂(NH₃)₄]⁺[AlCl₄]^? was carried out: see “Inhaltsübersicht”.     

NaAg3S2, ein Thioargentat mit dem Clusteranion [Ag6S4]2−

NaAg₃S₂, a Thioargentate Containing the Anionic Cluster [Ag₆S₄]^2? . Dark-red octahedrally shaped crystals of NaAg₃S₂ could be obtained by the reaction of NaAg(CN)₂ and NaCN in a stream of hydrogen sulfide at 630 K. NaAg₃S₂ crystallizes cubic, a=12.358(1) Å, space group Fd3 m, Z=16. The structure was determined from four-circle diffractometer data. NaAg₃S₂ contains the anionic cluster [Ag₆S₄]^2?. The structure can be traced back to the spinel structure typ. An extended Hückel calculation for the cluster anion, which is considered to be isolated, shows weak bonding silver-silver interactions. NaAg₃S₂ is diamagnetic at room temperature.     

Cs4[IrO4], ein neues Iridat mit planarem Anion [IrO4]4−

Cs₄[IrO₄], a New Iridate with Planar Anion [IrO₄]^4? For the first time we obtained black single crystals of Cs₄[IrO₄] by heating intimate mixtures of CsO_0.52 and IrO₂ (molar ratio Cs : Ir = 4.30 : 1.00; “Ag-bomb”, 740°C/86 d). Cs₄[IrO₄] crystallizes monocline, C 2/m, with a = 1031.66(8) pm, b = 671.61(4) pm, c = 660.44(6) pm, b? = 108.118(7)° and Z = 2 in the K₄[IrO₄]-type. The structure has been determined by four-circle-diffractometer data (PW 1100 from Phillips, Ag? Kα , graphite) with 841 I₀(hkl) with I ≥ 3s?(F) (from 947 I₀(hkl) out of 3529 measured reflexes). The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.     

AlCl3 · 3NH3 — eine Verbindung mit der Kristallstruktur eines Tetraammindichloroaluminium-diammintetrachloroaluminats: [AlCl2(NH3)4]+[AlCl4(NH3)2]−

AlCl₃ · 3NH₃ — a Compound with the Crystal Structure of a Tetraammine Dichloro Aluminium-Diammine Tetrachloro Aluminate: [AlCl₂(NH₃)₄]⁺[AlCl₄(NH₃)₂]^? . AlCl₃ · 3 NH₃ ? [AlCl₂(NH₃)₄]⁺ [AlCl₄(NH₃)₂]^? forms during the reaction of two mole NH₃ with AlCl₃(NH₃) at T ≥ 200°C. Repeated heating and cooling within 48 h between 200°C and 250°C gives a homogeneous product with total uptake of the necessary amount of NH₃. Slow sublimation in a vacuum line apparatus at 200°C gives crystals of the triammoniate sufficient for a X-ray structure determination: The compound contains elongated [AlCl₂(NH₃)₄]⁺ octahedra and compressed [AlCl₄(NH₃)₂]^? octahedra. Besides ionic bonding hydrogen bridge bonds with 3.369 Å ? d(N—H … Cl) ? 3.589 Å stabilize the atomic arrangement.     

Elektronenmikroskopische Untersuchungen zur Realstruktur von La2CeTaO6Cl3 und dessen thermischem Abbauprodukt La2CeCe TaO6Cl3−x

High Resolution Electron Microscopy Investigations of La₂CeTaO₆Cl₃ and its Thermal Decomposition Product La₂Ce Ce TaO₆Cl_3?x The thermal decomposition of the hexagonal La₂CeTaO₆Cl₃ led to a mixed-valent product La₂CeCe TaO₆Cl_3?x with a complicated monoclinic structure. The detailed inspection shows two subunits A and B, which form the monoclinic unit cell by a ABAB sequence. The subunit A is almost identical to the hexagonal cell of the starting material while subunit B has additional Ln- and Cl-positions. For this reason, the main structure features of the monoclinic compound and the starting material are related, which is clearly seen in the electron microscopy investigations. As might be expected from the relationship between the subunits A and B one can observe defects in the monoclinic compound arising from the various possibilities of combining these building elements. We also found structure defects in the hexagonal starting material, which are caused by the presence of the subunit B.     

Strukturen aus AIB2− und BaAl4−analogen Einheiten. I Die Verbindungen Sr4Pd5P5 und Sr2Pd3P3

Structures with AIB₂? and BaAl₄?type Units. I The Compounds Sr₄Pd₅P₅ and Sr₂Pd₃P₃ Sr₄Pd₅P₅ (Cmcm, a = 4.177(1) Å, b = 31.377(5) Å, c = 8.581(2) Å, Z = 4) und Sr₂ Pd₃P₃(Pmmm, a = 4.199(1) Å, b = 4.212(1) Å, c = 34.227(4) Å, Z = 4) have been prepared by heating the elements. Both structures contain exclusively units characteristic for the AIB_2? and BaAl₄?type. The ratio between isolated P-atoms and P₂?pairs is interpreted with an ionic splitting of the formulas.     

Synthese und Kristallstruktur von Na10[P4(NH)6N4](NH2)6(NH3)0,5 mit dem adamantanartig aufgebauten Anion [P4(NH)6N4]4−

Synthesis and Crystal Structure of Na₁₀[P₄(NH)₆N₄](NH₂)₆(NH₃)_0.5 with an Adamantane-like Anion [P₄(NH)₆N₄]^4? Crystals of Na₁₀[P₄(NH)₆N₄](NH₂)₆(NH₃)_0.5 were obtained by the reaction of P₃N₅ with NaNH₂ (molar ratio 1:20) within 5 d at 600°C in autoclaves. The following data characterize X-ray investigations: Fm3 m, Z = 8, a = 15.423(2) Å, Z(F) = 261 with F ≥ 3 σ(F) Z(Variables) = 27, R/R_w = 0.086/0.089 The compound contains the hitherto unknown anion [P₄(NH)₆N₄]^4?, which resembles adamantane. The total structure can be described as follows: The centers of gravity of units of [Na₈(NH₂)₆(NH₃)]²⁺ – 8Na⁺ on the corners of a cube, 6NH₂^? on the ones of an inscribed octahedron with NH₃ in the center – follow the motif of a cubic-closest packed arrangement. Units of [Na₁₂(NH₂)₆]⁶⁺ – 12Na⁺ on the corners of a cuboctahedron and 6NH₂^? on the ones of an inscribed octahedron – occupy all octahedral and those of [P₄(NH)₆N₄]^4? all tetrahedral sites.     

Ti9Se2 – Eine Verbindung mit kolumnaren [Ti9]-Baueinheiten

The Metal-Rich Titanium Selenide Ti₉Se₂ The new compound Ti₉Se₂ has been prepared as hitherto most metal-rich phase in the system titanium-selenium. It crystallizes in the orthorhombic space group Pbam (No. 55) with a = 691.7(2), b = 1 550.5(9), c = 345.4(2) pm. The structure consists of [Ti₉]-strings which are described within the concept of condensed clusters. The Se atoms are coordinated by tricapped trigonal prisms of Ti atoms.     

PdSCl,ein molekulares Palladium(II)-disulfidchlorid mit achtkernigen Pd8(S2)4Cl8−Komplexen und vierfach überbrückenden Disulfidgruppen

PdSCl, a Molecular Palladium(II) Disulfidechloride with Octanuclear Pd₈(S₂)₄Cl₈ Groups and with Tetra Metal-coordinated bridging Disulfide Groups Black crystals of PdSCl have been obtained by reaction of Pd with S₂Cl₂ in closed quartz ampoules at 200°C. The compound is to be formulated as a Palladium(II)-disulfidechloride consisting of Pd₈(S₂)₄Cl₈ molecules with approximately D_4h symmetry. In the octanuclear complexes Pd atoms form a cube, where bridging disulfide groups are found in front of 4 faces and μ₂?bridging Cl atoms on 8 edges. In the monoclinic crystal structure (a = 8.763(2) Å; b = 9.082(2) Å; c = 13.662(4) Å; β = 91.748(23)°; V = 1086.8 ų; Z = 16 PdSCl; Space gr. P2₁/n) the molecules form a cubic closed arrangement.     

NaTe3: eine Verbindung mit verbrückten Te126−-Clustern

NaTe₃ – a Compound with Cuban-like Clusters Te₁₂^6? NaTe₃ results as a greyish microcrystalline powder if stoichiometric amounts of the pure elements sodium and tellurium (molar ratio 1:3) are allowed to react in liquid ammonia at about ?50°C. After melting the crude product (500°C, 1 h, corundum crucible in sealed glass ampoule), followed by an annealing period (380°C, 5 days) NaTe₃ yields as a silvery compound with metallic lustre. NaTe₃ is trigonal, space group P3 c1, Z = 12, with a = 9.033(2) Å and c = 21.930(4) Å. It contains Te₆^2?-chains, linked together via their terminal atoms producing infinite strings. These strings may be thought to be built up of cuban-like clusters Te₁₂^6?.     

The electronic structure of two novel carbides,Ca3Cl2C3 and Sc3C4, containing C3 units

The triatomic C₃ unit that is known to exist in Mg₂C₃ has recently been found in the new compounds Ca₃Cl₂C₃ and Sc₃C₄. The electronic structure of these compounds is analyzed with the aid of extended Hückel Calculation. A fragment molecular Orbital analysis (FMO) is used to study the bonding characteristic of the C₃ unit in the ionic Ca₃Cl₂C₃, and in Sc₃C₄, the latter Containing C₂ unit and single C atoms as well. Sc₃C₄ Contain partially filled Sc (d) and C₂ bands leading to Metallic conductivity and Pauli Paramagnetism. The C? C bond distance in the diatomic C₂ units is significantly increased (d_{c? c}= 125 pm) relative to C^2?₂ or acetylene, because antibonding π*_g orbitals are partially filled. The unusual bending of the C₃ unit (d_{c? c}= 134 pm) in Sc₃C₄ (175,8°) and in Ca₃Cl₂C₃ (169,0°) is likely to be a result of the packing arrangement in these structures.     

Li2H3IO6, eine neue Variante der Molybdänitstruktur

Li₂H₃IO₆, a New Variant of the Molybdenite Structure Li₂H₃IO₆ crystallizes in P6₁ (a = 529.70(8), c = 2 759.6(5) pm; Z = 6). The crystals are twinned by merohedry, described by m ‖ [001] and 2 ? [001]. According to the results of an X-ray structure determination (2 778 diffractometer data, R_w = 0.047), Li₂H₃IO₆ exhibits a layer structure, with oxygen forming a distorted variant of the sulfur partial structure in molybdenite (MoS₂), however, with iodine and lithium in the more (Li) or less (I) distorted octahedral holes. The Li₂IO₆ packages are connected via strong hydrogen bonds along the edges of distorted trigonal prisms.     

Theoretical Investigation of the Stepwise Hydrolysis of the [Re3(μ‐Cl)3Cl9]3‐ Anion

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.     

RuS4Cl12 und Ru2S6Cl16, zwei neue Ruthenium(II)‐Komplexe mit SCl2‐Liganden

RuS₄Cl₁₂ and Ru₂S₆Cl₁₆, Two New Ruthenium(II) Complexes with SCl₂ Ligands Ru powder was reacted with SCl₂ in closed silika ampoules at 140 °C. From the black solution three compounds RuS₄Cl₁₂ 1 , Ru₂S₆Cl₁₆ 2 , and Ru₂S₄Cl₁₃ 3 could be crystallized and characterized by x ray analysis. Black crystals of 1 (monoclinic, a = 9.853(1) Å, b = 11.63(1) Å, c = 15.495(1) Å, β = 105.23(1)°, space group P2₁/c, z = 4) are identified as Trichlorsulfonium‐tris(dichlorsulfan)trichloro‐ruthenat(II) SCl₃[RuCl₃(SCl₂)₃]. In the structure the complex anions fac‐[RuCl₃(SCl₂)₃]^– and the cations [SCl₃]⁺ are connected to ion pairs by three chlorine bridges. The brown crystals of 2 (triclinic, a = 7.754(2) Å, b = 7.997(2) Å, c = 10.708(2) Å, α = 103.74(3)°, β = 98.44(3)°, γ = 108.58(3)°, space group P‐1, z = 1) contain the binuclear complex Bis‐μ‐chloro‐dichloro‐hexakis(dichlorsulfan)‐diruthenium(II), (SCl₂)₃ClRu(μ‐Cl)₂RuCl(SCl₂)₃ with two fac‐RuCl₃(SCl₂)₃‐units connected by two chlorine bridges. 3 was identifyed as a known mixed valence Ru(II,III) binuclear complex [Cl₂(SCl₂)Ru(μ‐Cl)₃Ru(SCl₂)₃]. The vibrational spectra and the thermal behaviour of the compounds are discussed.