Synthesis of Inorganic Structural Isomers By Diffusion‐Constrained Self‐Assembly of Designed Precursors: A Novel Type of Isomerism

The structure of precursors is used to control the formation of six possible structural isomers that contain four structural units of PbSe and four structural units of NbSe₂: [(PbSe)_1.14]₄[NbSe₂]₄, [(PbSe)_1.14]₃[NbSe₂]₃[(PbSe)_1.14]₁[NbSe₂]₁, [(PbSe)_1.14]₃[NbSe₂]₂[(PbSe)_1.14]₁[NbSe₂]₂, [(PbSe)_1.14]₂[NbSe₂]₃[(PbSe)_1.14]₂[NbSe₂]₁, [(PbSe)_1.14]₂[NbSe₂]₂[(PbSe)_1.14]₁[NbSe₂]₁[(PbSe)_1.14]₁[NbSe₂]₁, [(PbSe)_1.14]₂[NbSe₂]₁[(PbSe)_1.14]₁[NbSe₂]₂[(PbSe)_1.14]₁[NbSe₂]₁. The electrical properties of these compounds vary with the nanoarchitecture. For each pair of constituents, over 20 000 new compounds, each with a specific nanoarchitecture, are possible with the number of structural units equal to 10 or less. This provides opportunities to systematically correlate structure with properties and hence optimize performance.     

Synthesis,spectroscopic and structural characterisation of vanadium(IV) and oxovanadium(IV) complexes with arsenic donor ligands

The reaction of o-C₆H₄(AsMe₂)₂ with VCl₄ in anhydrous CCl₄ produces orange eight-coordinate [VCl₄{o-C₆H₄(AsMe₂)₂}₂], whilst in CH₂Cl₂ the product is the brown, six-coordinate [VCl₄{o-C₆H₄(AsMe₂)₂}]. In dilute CH₂Cl₂ solution slow decomposition occurs to form the V^III complex [V₂Cl₆{o-C₆H₄(AsMe₂)₂}₂]. Six-coordination is also found in [VCl₄{MeC(CH₂AsMe₂)₃}] and [VCl₄{Et₃As)₂]. Hydrolysis of these complexes occurs readily to form vanadyl (VO²⁺) species, pure samples of which are obtained by reaction of [VOCl₂(thf)₂(H₂O)] with the arsines to form green [VOCl₂{o-C₆H₄(AsMe₂)₂}], [VOCl₂{MeC(CH₂AsMe₂)₃}(H₂O)] and [VOCl₂(Et₃As)₂]. Green [VOCl₂(o-C₆H₄(PMe₂)₂}] is formed from [VOCl₂(thf)₂(H₂O)] and the ligand. The [VOCl₂{o-C₆H₄(PMe₂)₂}] decomposes in thf solution open to air to form the diphosphine dioxide complex [VO{o-C₆H₄(P(O)Me₂)₂}₂(H₂O)]Cl₂, but in contrast, the products formed from similar treatment of [VCl₄{o-C₆H₄(AsMe₂)₂}_x] or [VOCl₂{o-C₆H₄(AsMe₂)₂}] contain the novel arsenic(V) cation [o-C₆H₄(AsMe₂Cl)(μ-O)(AsMe₂)]⁺. X-ray crystal structures are reported for [V₂Cl₆{o-C₆H₄(AsMe₂)₂}₂], [VO(H₂O){o-C₆H₄(P(O)Me₂)₂}₂]Cl₂, [o-C₆H₄(AsMe₂Cl)(μ-O)(AsMe₂)]Cl·[VO(H₂O)₃Cl₂] and powder neutron diffraction data for [VCl₄{o-C₆H₄(AsMe₂)₂}₂].     

Reaktionen von R4Sb2 (R = Me,Et) mit (Me3SiCH2)3M (M = Ga,In) und Kristallstrukturen von [(Me3SiCH2)2InSbMe2]3 und [(Me3SiCH2)2GaOSbEt2]2

Reactions of R₄Sb₂ (R = Me, Et) with (Me₃SiCH₂)₃M (M = Ga, In) and Crystal Structures of [(Me₃SiCH₂)₂InSbMe₂]₃ and [(Me₃SiCH₂)₂GaOSbEt₂]₂ The reaction of (Me₃SiCH₂)₃In with Me₂SbSbMe₂ gives [(Me₃SiCH₂)₂InSbMe₂]₃ ( 1 ) and Me₃SiCH₂SbMe₂. [(Me₃SiCH₂)₂GaOSbEt₂]₂ ( 2 ) is formed by the reaction of (Me₃SiCH₂)₃Ga with Et₂SbSbEt₂ and oxygen. The syntheses and the crystal structures of 1 and 2 are reported.     

Synthesen und Eigenschaften von Tris(perfluoralkyl)arsen- und -antimon(III,V)-Verbindungen

Preparations and Properties of Tris(perfluoroalkyl) Arsenic and Antimony(III, V) Compounds As(R_f)₃ and Sb(R_f)₃ (R_f?C₂F₅, C₄F₉, C₆F₁₃) are prepared in good yields by the polar reactions of AsCl₃ and SbCl₃ with bis(perfluoroalkyl) cadmium compounds as colourless liquids or solids. The oxidation of As(C₂F₅)₃ and Sb(C₂F₅)₃ with XeF₂ gives the difluorides M(C₂F₅)₃F₂ (M?As, Sb). As(C₂F₅)₃Cl₂ is prepared by chlorination of As(C₂F₅)₃ in the presence of AlCl₃, while Sb(C₂F₅)₃Cl₂ is formed in the reaction of Sb(C₂F₅)₃F₂ with (CH₃)₃SiCl. During the reaction of M(C₂F₅)₃F₂ with (CH₃)₃SiBr ¹⁹F-NMR spectroscopic evidence is found for M(C₂F₅)₃ Br₂. The thermal decompositions of M(C₂F₅)₃F₂ mainly yield C₄F₁₀ and M(C₂F₅)F₂, while the thermal decompositions of M(C₂F₅)₃Cl₂ yield M(C₂F₅)₂Cl and C₂F₅Cl. The properties and spectroscopic data of the new compounds are described.     

Incorporation of Sulfate or Selenate Groups into Oxotellurates(IV): I. Calcium,Cadmium, and Strontium Compounds

Seven new mixed oxochalcogenate compounds in the systems M^II/X^VI/Te^IV/O/(H), (M^II = Ca, Cd, Sr; X^VI = S, Se) were obtained under hydrothermal conditions (210 °C, one week). Crystal structure determinations based on single‐crystal X‐ray diffraction data revealed the compositions Ca₃(SeO₄)(TeO₃)₂, Ca₃(SeO₄)(Te₃O₈), Cd₃(SeO₄)(Te₃O₈), Cd₃(H₂O)(SO₄)(Te₃O₈), Cd₄(SO₄)(TeO₃)₃, Cd₅(SO₄)₂(TeO₃)₂(OH)₂, and Sr₃(H₂O)₂(SeO₄)(TeO₃)₂ for these phases. Peculiar features of the crystal structures of Ca₃(SeO₄)(TeO₃)₂, Ca₃(SeO₄)(Te₃O₈), Cd₃(SeO₄)(Te₃O₈), Cd₃(H₂O)(SO₄)(Te₃O₈), and Sr₃(H₂O)₂(SeO₄)(TeO₃)₂ are metal‐oxotellurate(IV) layers connected by bridging XO₄ tetrahedra and/or by hydrogen‐bonding interactions involving hydroxyl or water groups, whereas Cd₄(SO₄)(TeO₃)₃ and Cd₅(SO₄)₂(TeO₃)₂(OH)₂ crystallize as framework structures. Common to all crystal structures is the stereoactivity of the Te^IV electron lone pair for each oxotellurate(IV) unit, pointing either into the inter‐layer space, or into channels and cavities in the crystal structures.     

Chloroselenate mit zwei- und vierwertigem Selen: 77Se-NMR-Spektren,Synthese und Kristallstrukturen von (PPh4)2SeCl6 · 2 CH2Cl2, (NMe3Ph)2SeCl6, (K-18-Krone-6)2SeCl6 · 2 CH3CN,PPh4Se2Cl9, (NEt4)2Se2Cl10, (PPh4)2Se3Cl8 · CH2Cl2 und (PPh4)2Se4Cl12 · CH2Cl2

Chloroselenates with Di- and Tetravalent Selenium: ⁷⁷Se-NMR-Spectra, Syntheses, and Crystal Structures of (PPh₄)₂SeCl₆ · 2 CH₂Cl₂, (NMe₃Ph)₂SeCl₆, (K-18-crown-6)₂SeCl₆ · 2 CH₃CN, PPh₄Se₂Cl₉, (NEt₄)₂Se₂Cl₁₀, (PPh₄)₂Se₃Cl₈ · CH₂Cl₂, and (PPh₄)₂Se₄Cl₁₂ · CH₂Cl₂ The title compounds were obtained from reactions of selenium and selenium tetrachloride with PPh₄Cl, NEt₄Cl, NMe₃PhCl, or (K-18-crown-6)Cl in dichloromethane or acetonitrile. (PPh₄)₂Se₃Cl₈ · CH₂Cl₂ was also formed from GeSe, PPh₄Cl and chlorine in acetonitrile. The ⁷⁷Se-NMR spectra of the solutions show the presence of dynamical equilibria which, depending on composition, mainly contain SeCl₂, SeCl₄, Se₂Cl₂, SeCl₆^2–, Se₂Cl₆^2–, and/or Se₂Cl₁₀^2–. Solutions of AsCl₃ and (PPh₄)₂Se₄ in acetonitrile upon chlorination with Cl₂ or PPh₄AsCl₆ yielded (PPh₄)₂Se₂Cl₆, while (PPh₄)₂As₂Se₄Cl₁₂ was the product after chlorination with SOCl₂. According to the X-ray crystal structure analyses the ions SeCl₆^2–, Se₂Cl₉^–, and Se₂Cl₁₀^2– have the known structures with octahedral coordination of the Se atoms. The structure of the Se₃Cl₈^2– ion corresponds to that of Se₃Br₈^2– consisting of three SeCl₂ molecules associated via two Cl^– ions. (PPh₄)₂Se₄Cl₁₂ · CH₂Cl₂ is isotypic with the corresponding bromoselenate and contains anions in which three SeCl₂ molecules are attached to a SeCl₆^2– ion; there is a peculiar Se–Se interaction.     

Piperazine Functionalization of C70 for Incorporation into Supramolecular Assemblies

The photochemical reaction of piperazine with C₇₀ produces a mono‐adduct (N(CH₂CH₂)₂NC₇₀) in high yield (67 %) along with three bis‐adducts. These piperazine adducts can combine with various Lewis acids to form crystalline supramolecular aggregates suitable for X‐ray diffraction. The structure of the mono‐adduct was determined from examination of the adduct I₂N(CH₂CH₂)₂NI₂C₇₀ that was formed by reaction of N(CH₂CH₂)₂NC₇₀ with I₂. Crystals of polymeric {Rh₂(O₂CCF₃)₄N(CH₂CH₂)₂NC₇₀}_n?nC₆H₆ that formed from reaction of the mono‐adduct with Rh₂(O₂CCF₃)₄ contain a sinusoidal strand of alternating molecules of N(CH₂CH₂)₂NC₇₀ and Rh₂(O₂CCF₃)₄ connected through Rh?N bonds. Silver nitrate reacts with N(CH₂CH₂)₂NC₇₀ to form black crystals of {(Ag(NO₃))₄(N(CH₂CH₂)₂NC₇₀)₄}_n?7nCH₂Cl₂ that contain parallel, nearly linear chains of alternating (N(CH₂CH₂)₂NC₇₀ molecules and silver ions. Four of these {Ag(NO₃)N(CH₂CH₂)₂NC₇₀}_n chains adopt a structure that resembles a columnar micelle with the ionic silver nitrate portion in the center and the nearly non‐polar C₇₀ cages encircling that core. Of the three bis‐adducts, one was definitively identified through crystallization in the presence of I₂ as ¹²{N(CH₂CH₂)₂N}₂C₇₀ with addends on opposite poles of the C₇₀ cage and a structure with C_2v symmetry. In ¹²{I₂N(CH₂CH₂)₂N}₂C₇₀, individual ¹²{I₂N(CH₂CH₂)₂N}₂C₇₀ units are further connected by secondary I2???N2 interactions to form chains that occur in layers within the crystal. Halogen bond formation between a Lewis base such as a tertiary amine and I₂ is suggested as a method to produce ordered crystals with complex supramolecular structures from substances that are otherwise difficult to crystallize.     

Molecular Cage Assembly by Sn−O−Sn Bridging of Di-, Tri- and Tetranuclear Organotin Tectons: Extending the Spacing in Double Ladder Structures

Hydrolysis reactions of di- and trinuclear organotin halides yielded large novel cage compounds containing Sn−O−Sn bridges. The molecular structures of two octanuclear tetraorganodistannoxanes showing double-ladder motifs, viz., [{Me₃SiCH₂(Cl)SnCH₂YCH₂Sn(OH)CH₂SiMe₃}₂(μ-O)₂]₂ [ 1 , Y=p-(Me)₂SiC₆H₄-C₆H₄Si(Me)₂] and [{Me₃SiCH₂(I)SnCH₂YCH₂Sn(OH)CH₂SiMe₃}₂(μ-O)₂]₂ ⋅ 0.48 I₂ [ 2⋅ 0.48 I₂, Y=p-(Me)₂SiC₆H₄-C₆H₄Si(Me)₂], and the hexanuclear cage-compound 1,3,6-C₆H₃(p-C₆H₄Si(Me)₂CH₂Sn(R)₂OSn(R)₂CH₂Si(Me)₂C₆H₄-p)₃C₆H₃-1,3,6 ( 3 , R=CH₂SiMe₃) are reported. Of these, the co-crystal 2⋅ 0.48 I₂ exhibits the largest spacing of 16.7 Å reported to date for distannoxane-based double ladders. DFT calculations for the hexanuclear cage and a related octanuclear congener accompany the experimental work.     

The ternary system cerium-rhodium-silicon

Phase relations have been established in the ternary system Ce-Rh-Si for the isothermal section at 800 °C based on X-ray powder diffraction and EPMA on about 80 alloys, which were prepared by arc melting under argon or by powder reaction sintering. From the 25 ternary compounds observed at 800 °C 13 phases have been reported earlier. Based on XPD Rietveld refinements the crystal structures for 9 new ternary phases were assigned to known structure types. Structural chemistry of these compounds follows the characteristics already outlined for their prototype structures: τ₇—Ce₃RhSi₃, (Ba₃Al₂Ge₂-type), τ₈—Ce₂Rh_3−xSi_3+x (Ce₂Rh_1.35Ge_4.65-type), τ₁₀—Ce₃Rh_4−xSi_4+x (U₃Ni₄Si₄-type), τ₁₁—CeRh₆Si₄ (LiCo₆P₄-type), τ₁₃—Ce₆Rh₃₀Si_19.3 (U₆Co₃₀Si₁₉-type), τ₁₈—Ce₄Rh₄Si₃ (Sm₄Pd₄Si₃-type), τ₂₁—CeRh₂Si (CeIr₂Si-type), τ₂₂—Ce₂Rh_3+xSi_1−x (Y₂Rh₃Ge-type) and τ₂₄—Ce₈(Rh_1−xSi_x)₂₄Si (Ce₈Pd₂₄Sb-type). For τ₂₅—Ce₄(Rh_1−xSi_x)₁₂Si a novel bcc structure was proposed from Rietveld analysis. Detailed crystal structure data were derived for τ₃—CeRhSi₂ (CeNiSi₂-type) and τ₆—Ce₂Rh₃Si₅ (U₂Co₃Si₅-type) by X-ray single crystal experiments, confirming the structure types. The crystal structures of τ₄—Ce₂₂Rh₂₂Si₅₆, τ₅—Ce₂₀Rh₂₇Si₅₃ and τ₂₃—Ce_33.3Rh_58.2−55.2Si_8.5−11.5 are unknown. High temperature compounds with compositions Ce₁₀Rh₅₁Si₃₃ (U₁₀Co₅₁Si₃₃-type) and CeRhSi (LaIrSi-type) have been observed in as-cast alloys but these phases do not participate in the phase equilibria at 800 °C.     

Ruthenium NNN complexes with a 2‐hydroxypyridylmethylene fragment for transfer hydrogenation of ketones

Four NNN tridentate ligands L₁–L₄ containing 2‐methoxypyridylmethene or 2‐hydroxypyridylmethene fragment were synthesized and introduced to ruthenium centers. When (HOC₅H₃NCH₂C₅H₃NC₅H₇N₂) (L₂) and (HOC₅H₃NCH₂C₅H₃NC₆H₆N₃) (L₄) reacted with RuCl₂(PPh₃)₃, two ruthenium chloride products Ru(L₂)(PPh₃)Cl₂ ( 1 ) and Ru(L₄)(PPh₃)Cl₂ ( 2 ) were isolated, respectively. Reactions of (MeOC₅H₃NCH₂C₅H₃NC₅H₇N₂) (L₁) and (MeOC₅H₃NCH₂C₅H₃NC₆H₆N₃) (L₃) with RuCl₂(PPh₃)₃ in the presence of NH₄PF₆ generated two dicationic complexes [Ru(L₁)₂][PF₆]₂ ( 3 ) and [Ru(L₃)₂][PF₆]₂ ( 4 ), respectively. Complex 1 reacted with CO to afford product [Ru(L₂)(PPh₃)(CO)Cl][Cl]. The catalytic activity for transfer hydrogenation of ketones was investigated. Complex 1 showed the highest activity, with a turnover frequency value of 1.44 × 10³ h^?1 for acetophenone, while complexes 3 and 4 were not active.     

Group 6 Oxyfluoro-Anion Salts of [XeF5]+ and [Xe2F11]+: Syntheses and Structures of [XeF5][M2O2F9] (M=Mo,W), [Xe2F11][M′OF5] (M′=Cr,Mo, W), [XeF5][HF2]⋅CrOF4, and [XeF5][WOF5]⋅XeOF4

The reactions of the fluoride-ion donor, XeF₆, with the fluoride-ion acceptors, M′OF₄ (M′=Cr, Mo, W), yield [XeF₅]⁺ and [Xe₂F₁₁]⁺ salts of [M′OF₅]⁻ and [M₂O₂F₉]⁻ (M=Mo, W). Xenon hexafluoride and MOF₄ react in anhydrous hydrogen fluoride (aHF) to give equilibrium mixtures of [Xe₂F₁₁]⁺, [XeF₅]⁺, [(HF)_nF]⁻, [MOF₅]⁻, and [M₂O₂F₉]⁻ from which the title salts were crystallized. The [XeF₅][CrOF₅] and [Xe₂F₁₁][CrOF₅] salts could not be formed from mixtures of CrOF₄ and XeF₆ in aHF at low temperature (LT) owing to the low fluoride-ion affinity of CrOF₄, but yielded [XeF₅][HF₂]⋅CrOF₄ instead. In contrast, MoOF₄ and WOF₄ are sufficiently Lewis acidic to abstract F⁻ ion from [(HF)_nF]⁻ in aHF to give the [MOF₅]⁻ and [M₂O₂F₉]⁻ salts of [XeF₅]⁺ and [Xe₂F₁₁]⁺. To circumvent [(HF)_nF]⁻ formation, [Xe₂F₁₁][CrOF₅] was synthesized at LT in CF₂ClCF₂Cl solvent. The salts were characterized by LT Raman spectroscopy and LT single-crystal X-ray diffraction, which provided the first X-ray crystal structure of the [CrOF₅]⁻ anion and high-precision geometric parameters for [MOF₅]⁻ and [M₂O₂F₉]⁻. Hydrolysis of [Xe₂F₁₁][WOF₅] by water contaminant in HF solvent yielded [XeF₅][WOF₅]⋅XeOF₄. Quantum-chemical calculations were carried out for M′OF₄, [M′OF₅]⁻, [M′₂O₂F₉]⁻, {[Xe₂F₁₁][CrOF₅]}₂, [Xe₂F₁₁][MOF₅], and {[XeF₅][M₂O₂F₉]}₂ to obtain their gas-phase geometries and vibrational frequencies to aid in their vibrational mode assignments and to assess chemical bonding.     

Preparation of the First Manganese(III) and Manganese(IV) Azides

Fluoride‐azide exchange reactions of Me₃SiN₃ with MnF₂ and MnF₃ in acetonitrile resulted in the isolation of Mn(N₃)₂ and Mn(N₃)₃?CH₃CN, respectively. While Mn(N₃)₂ forms [PPh₄]₂[Mn(N₃)₄] and (bipy)₂Mn(N₃)₂ upon reaction with PPh₄N₃ and 2,2′‐bipyridine (bipy), respectively, the manganese(III) azide undergoes disproportionation and forms mixtures of [PPh₄]₂[Mn(N₃)₄] and [PPh₄]₂[Mn(N₃)₆], as well as (bipy)₂Mn(N₃)₂ and (bipy)Mn(N₃)₄. Neat and highly sensitive Cs₂[Mn(N₃)₆] was obtained through the reaction of Cs₂MnF₆ with Me₃SiN₃ in CH₃CN.     

High-nuclearity Ni-substituted polyoxometalates: a series of poly(polyoxotungstate)s containing 20–22 nickel centers

Three high‐nuclearity Ni‐substituted polyoxotungstates (POTs)—[Ni(enMe)₂(H₂O)₂]₂[Ni(H₂O)₆]₂‐ [Ni(enMe)₂][Ni(H₂O)₂]_1.5[HNi₂₀X₄W₃₄‐ (OH)₄O₁₃₆(H₂O)₆(enMe)₈] ? 11 H₂O ( 3 ), [Ni(en)₂(H₂O)]₂[H₈Ni₂₁X₄W₃₄(OH)₄‐ O₁₃₆(en)₁₀(H₂O)₅] ? 22 H₂O ( 4 ), and [Ni‐(enMe)₂]₂[H₆Ni₂₂X₄W₃₄(OH)₄O₁₃₆(H₂O)₆(enMe)₁₀] ? 18 H₂O ( 5 ), in which en=ethylenediamine, enMe=1,2‐diaminopropane, X=0.5 P+0.5 Ge—were made under hydrothermal conditions and characterized by IR spectroscopy, elemental analysis, thermogravimetric analysis, powder X‐ray diffraction, and single‐crystal X‐ray diffraction. The structures of 3 – 5 can be viewed as novel derivatives of [H₆Ni₂₀P₄W₃₄(OH)₄O₁₃₆(enMe)₈‐ (H₂O)₆] ? 12 H ₂O ( 1 ) and [Ni(en)₂‐ (H₂O)]₂[H₈Ni₂₀P₄W₃₄(OH)₄O₁₃₆(en)₉‐ (H₂O)₄] ? 16 H ₂O ( 2 ), which both contain 20 nickel ions per structural unit. Compound 3 is the first example of a 1D cluster chain constructed from Ni₂₀‐substituted polyanions [HNi₂₀X₄‐ W₃₄(OH)₄O₁₃₆(H₂O)₆(enMe)₈]^11? and [Ni(enMe)₂]²⁺ bridges. Compound 4 is a novel cluster–organic chain built by Ni₂₁‐substituted polyanions [H₈Ni₂₁X₄W₃₄(OH)₄O₁₃₆(en)₁₀(H₂O)₅]^4? and en molecule bridges. Compound 5 is a discrete POT with 22 Ni centers, and is not only the largest nickel‐substituted POT, but also contains the highest number of nickel ions in one polyanion to date. Magnetic measurements illustrate that overall ferromagnetic interactions exist in 1 – 5 . The magnetic behavior of 1 and 2 was theoretically simulated by the MAGPACK magnetic program package.     

One- and Two-Electron Transfer Oxidation of 1,4-Disilabenzene with Formation of Stable Radical Cations and Dications

Electron-transferable oxidants such as B(C₆F₅)₃/nBuLi, B(C₆F₅)₃/LiB(C₆F₅)₄, B(C₆F₅)₃/LiHBEt₃, Al(C₆F₅)₃/(o-RC₆H₄)AlH₂ (R=N(CMe₂CH₂)₂CH₂), B(C₆F₅)₃/AlEt₃, Al(C₆F₅)₃, Al(C₆F₅)₃/nBuLi, Al(C₆F₅)₃/AlMe₃, (CuC₆F₅)₄, and Ag₂SO₄, respectively were employed for reactions with (L)₂Si₂C₄(SiMe₃)₂(C₂SiMe₃)₂ (L=PhC(NtBu)₂, 1 ). The stable radical cation [ 1 ]^+. was formed and paired with the anions [nBuB(C₆F₅)₃]⁻ (in 2 ), [B(C₆F₅)₄]⁻ (in 3 ), [HB(C₆F₅)₃]⁻ (in 4 ), [EtB(C₆F₅)₃]⁻ (in 5 ), {[(C₆F₅)₃Al]₂(μ-F)]⁻ (in 6 ), [nBuAl(C₆F₅)₃]⁻ (in 7 ), and [Cu(C₆F₅)₂]⁻ (in 8 ), respectively. The stable dication [ 1 ]²⁺ was also generated with the anions [EtB(C₆F₅)₃]⁻ ( 9 ) and [MeAl(C₆F₅)₃]⁻ ( 10 ), respectively. In addition, the neutral compound [(L)₂Si₂C₄(SiMe₃)₂(C₂SiMe₃)₂][μ-O₂S(O)₂] ( 11 ) was obtained. Compounds 2 – 11 are characterized by UV-vis absorption spectroscopy, X-ray crystallography, and elemental analysis. Compounds 2 – 8 are analyzed by EPR spectroscopy and compounds 9 – 11 by NMR spectroscopy. The structure features are discussed on the central Si₂C₄-rings of 1 , [ 1 ]^+., [ 1 ]²⁺, and 11 , respectively.     

Synthesen und Kristallstrukturen neuer heterobimetallischer Tantal‐Münzmetall‐Chalkogenido‐Cluster

Syntheses and Crystal Structures of Novel Heterobimetallic Tantalum Coin Metal Chalcogenido Clusters In the presence of phosphine the thiotantalats (Et₄N)₄[Ta₆S₁₇] · 3MeCN reacts with copper to give a number of new heterobimetallic tantalum copper chalcogenide clusters. These clusters show metal chalcogenide units some of which here already known from the chemistry of vanadium and niobium. New Ta—M‐chalcogenide clusters could also be synthesised by reaction of TaCl₅ and silylated chalcogen reagents with copper or silver salts in presence of phosphine. Such examples are: [Ta₂Cu₂S₄Cl₂(PMe₃)₆] · DMF ( 1 ), (Et₄N)[Ta₃Cu₅S₈Cl₅(PMe₃)₆] · 2MeCN ( 2 ), (Et₄N)[Ta₉Cu₁₀S₂₄Cl₈(PMe₃)₁₄] · 2MeCN ( 3 ), [Ta₄Cu₁₂Cl₈S₁₂(PMe₃)₁₂] ( 4 ), (Et₄N)[Ta₂Cu₆S₆Cl₅(PPh₃)₆] · 5MeCN ( 5 ), (Et₄N)[Ta₂Cu₆S₆Cl₅(PPh₂Me)₆] · 2MeCN ( 6 ), (Et₄N)[Ta₂Cu₆S₆Cl₅(P^tBu₂Cl)₆] · MeCN ( 7 ) [Ta₂Cu₂S₄Br₄(PPh₃)₂(MeCN)₂] · MeCN ( 8 ), [Cu(PMe₃)₄]₂[Ta₂Cu₆S₆(SCN)₆(PMe₃)₆] · 4MeCN ( 9 ), [TaCu₅S₄Cl₂(dppm)₄] · DMF ( 10 ), [Ta₂Cu₂Se₄(SCN)₂(PMe₃)₆] ( 11 ), [Cu(PMe₃)₄]₂[Ta₂Cu₆Se₆(SCN)₆(PMe₃)₆] · 4MeCN ( 12 ), [TaCu₄Se₄(PⁿPr₃)₆][TaCl₆] ( 13 ), [Ta₂Ag₂Se₄Cl₂(PMe₃)₆] · MeCN ( 14 ), _∞[TaAg₃Se₄(PMe₃)₃] ( 15 ). The structures of these compounds were obtained by X‐ray single crystal structure analysis.     

Reactions of Bromine Fluoride Dioxide,BrO2F,for the Generation of the Mixed‐Valent Bromine Oxygen Cations Br3O4+ and Br3O6+

A reliable synthesis of unstable and highly reactive BrO₂F is reported. This compound can be converted into BrO₂⁺SbF₆^?, BrO₂⁺AsF₆^?_, and BrO₂⁺AsF₆^??2 BrO₂F. The latter decomposes into mixed‐valent Br₃O₄?Br₂⁺AsF₆^? with five‐, three‐, one‐, and zero‐valent bromine. BrO₂⁺ H(SO₃CF₃)₂^? is formed with HSO₃CF₃. Excess BrO₂F yields mixed‐valent Br₃O₆⁺OSO₃CF₃^? with five‐ and three‐valent bromine. Reactions of BrO₂F and MoF₅ in SO₂ClF or CH₂ClF result in Cl₂BrO₆⁺Mo₃O₃F₁₃^?. The reaction of BrO₂F with (CF₃CO)₂O and NO₂ produces O₂Br‐O‐CO‐CF₃ and the known NO₂⁺Br(ONO₂)₂^?. All of these compounds are thermodynamically unstable.     

New Nanostructured Materials: Synthesis of Dodecanuclear NiII Complexes and Surface Deposition Studies

Microwave‐assisted synthesis has been used to obtain the family of dodecanuclear Ni^II complexes [Ni₁₂(NO₃)(MeO)₁₂(MeC₆H₄CO₂)₉(MeOH)₁₀(H₂O)₂][ClO₄]₂ ( 1 ), [Ni₁₂(NO₃)(MeO)₁₂(BrC₆H₄CO₂)₉(MeOH)₁₀(H₂O)₂][ClO₄]₂ ( 2 ), [Ni₁₂(CO₃)(MeO)₁₂(MeC₆H₄CO₂)₉(MeOH)₁₀(H₂O)₂]₂[SO₄] ( 3 ) and [Ni₁₂(NO₃)(MeO)₁₂(MeC₆H₄CO₂)₉(MeOH)₈(H₂O)₇][NO₃]₂ ( 4 ). They contain three {Ni₄O₄} cubane units which template around a central μ₆ anion, either NO₃^? or CO₃^2?. Their magnetic properties have been studied by superconducting quantum interference device (SQUID) magnetometry and high‐field EPR measurements. The nanostructuration of the Ni₁₂ species on mica surfaces is studied by AFM and grazing‐incidence X‐ray diffraction, which reveal the formation of polycrystalline thin layers.     

Syntheses of double- and triple-decker clusters of osmium and cobalt metals linked by cyclotetradeca-1,8-diyne ligands

Photoirradiation of Os₃(CO)₁₀(C₁₄H₂₀) (1) in n-hexane produces the double-decker cluster [Os₃(CO)₉(C₂₈H₄₀)] [Os₃(CO)₁₀] (7), which can also be prepared from the reaction of Os₃(CO)₉(C₂₈H₄₀) (2) and Os₃(CO)₁₀(NCMe)₂. Further reaction of 7 with Os₃(CO)₁₀(NCMe)₂ affords the triple-decker cluster [Os₃(CO)₉(C₂₈H₄₀)][Os₃(CO)₁₀]₂ (8). The bis(diyne) complex Os₃(CO)₈(C₁₄H₂₀)₂ (3) reacts with Os₃(CO)₁₀(NCMe)₂ sequentially to yield the double-decker cluster [Os₃(CO)₈(C₁₄H₂₀)₂][Os₃(CO)₁₀] (4) and the triple-decker cluster [Os₃(CO)₈(C₁₄H₂₀)₂][Os₃(CO)₁₀]₂ (5). Treatment of 3 with Co₂(CO)₈ at room temperature leads to the mixed-metal triple-decker cluster [Os₃(CO)₈(C₁₄H₂₀)₂][Co₂(CO)₆]₂ (6), while the reaction of 2 and Co₂(CO)₈ produces [Os₃(CO)₉(C₂₈H₄₀)][Co₂(CO)₆]₂ (9) and [Os₂(CO)₆(C₂₈H₄₀)][Co₂(CO)₆]₂ (10). Compound 10, which involves cluster degradation from Os₃ to Os₂, has been structurally characterized by an X-ray diffraction study.     

Preparation of Tellurium‐Nitrogen containing Moieties in Ionic Chainmolecules,Heterocycles, as well as (CF3Se)2Te, (CF3S)2Se,and (CH3)2Te(X)Y (X = Y = NCO,NSO; X = Cl,Y = NSO)

The reaction between Cl₂Te(NSO)₂, Cl₆Te₂N₂S and Cl₂Te(N=S=N)₂TeCl₂ with MCl₃ provided the compounds [(Cl₂Te)₂N⁺][MCl₄^–] (M = Ga, Al, Fe). Treating Cl₆Te₂N₂S with M′Cl₃ yielded besides [(Cl₂Te)₂N⁺][M′Cl₄^–] (M′ = Al, Fe) the sulfur containing compound [ClTeNSNS⁺][M′Cl₄^–]. The structure for [ClTeNSNS⁺][FeCl₄^–] was established by an X‐ray structure analysis. With Te(NSO)₂ and CF₃SCl, via Cl₂Te(NSO)₂, the known compound Te₂NCl₅ was formed. Tetrafluoroditelluradiazetidine was obtained from TeF₄ and [(CH₃)₃Si]₂NH which on treating with (CH₃)₃SiCl provided the corresponding chloroderivative. In addition metathetical reaction between Cl₂TeNSNS and CF₃C(O)OAg yielded [CF₃C(O)O]₂TeSNSN. Similarly (CH₃)₂Te(NSO)_2–xCl_x (x = 0,1) and (CH₃)₂Te(NCO)₂ were made from (CH₃)₂TeCl₂ and AgNSO or AgNCO, respectively. Halogination of Cl₂Te(N=S=N)₂TeCl₂ with Cl₂ or Br₂ yielded Cl₆Te₂N₂S and Cl₄Br₂Te₂N₂S. The bromoderivate was also prepared from Cl₂Te(NSO)₂ and Br₂. AgNSO was synthesized by treating CF₃C(O)OAg with (CH₃)₃SiNSO. Two other synthons (CF₃Se)₂Te and (CF₃S)₂Se were obtained from CF₃SeCl and Na₂Te and from Hg(SCF₃)₂ plus SeCl₄, respectively.     

Preparation, crystal structure, and photoluminescence of Ca2SnO4:Eu, Y

Eu³⁺-doped Ca₂SnO₄ (solid solutions of Ca_2−xEu_2xSn_1−xO₄, 0?x?0.3) and Eu³⁺ and Y³⁺-codoped Ca₂SnO₄ (Ca_1.8Y_0.2Eu_0.2Sn_0.8O₄) were prepared by solid-state reaction at 1400 °C in air. Rietveld analysis of the X-ray powder diffraction patterns revealed that Eu³⁺ replaced Ca²⁺ and Sn⁴⁺ in Eu³⁺-doped Ca₂SnO₄, and that Eu³⁺ replaced Ca²⁺ and Y³⁺ replaced Sn⁴⁺ in Ca_1.8Y_0.2Eu_0.2Sn_0.8O₄. Red luminescence at 616 nm due to the electric dipole transition ⁵D_o→⁷F₂ was observed in the photoluminescence (PL) spectra of Ca_2−xEu_2xSn_1−xO₄ and Ca_1.8Y_0.2Eu_0.2Sn_0.8O₄ at room temperature. The maximum PL intensity in the solid solutions of Ca_2−xEu_2xSn_1−xO₄ was obtained for x=0.1. The PL intensity of Ca_1.8Y_0.2Eu_0.2Sn_0.8O₄ was 1.26 times greater than that of Ca_2−xEu_2xSn_1−xO₄ with x=0.1.