Synthese und Struktur von RbHfF5, Rb2Zr3F12O und Rb2Hf3F12O — zwei Oxidfluoride mit zentraler trigonal‐planarer [M3O]‐Gruppe

Synthesis and Structure of RbHfF₅, Rb₂Zr₃F₁₂O and Rb₂Hf₃F₁₂O — two Oxydefluorides with Central Trigonal‐plane [M₃O] Group Colorless RbHfF₅ crystallizes isotypic with (NH₄)ZrF₅ and TlHfF₅ monoclinic, space group P2₁/c ‐ C_2h (No. 14) with a = 776.6, b = 789.6, c = 789.8 pm, and β = 120.52°. Also colorless Rb₂Zr₃F₁₂O crystallizes trigonal, space group R3¯m — D₃d (No. 166), with a = 771.9 and c = 2963.0 pm, isotypic is Rb₂Hf₃F₁₂O with a = 769.2 pm and c = 2986.1 pm. Both compounds are isotypic with Tl₂Zr₃F₁₂O.     

Zum chemischen Transport von ZrO2 und HfO2 mit den Transportmitteln Cl2 und TeCl4

On the Chemical Transport of ZrO₂ and HfO₂ with the Transport Agents Cl₂ and TeCl₄ ZrO₂ und HfO₂ migrate in a temperature gradient (1100 → 1000°C) with the transport agent either Cl₂ or TeCl₄ by endothermic transport reaction. At experiments in silica glass tubes with TeCl₄ well developed crystals of ZrO₂ could be obtained. From HfO₂, as from both oxides using Cl₂, only powdery products are formed. The transport rates with TeCl₄ were higher than with Cl₂. The influence of different pressures was examined for the transport of ZrO₂ with TeCl₂ with thermochemical model calculations the expected transport rates could be investigated. The large correspondence between calculated and experimental received values speaks for a true interpretation of the transport observations.     

Bromoplumbate mit kettenförmigen und isolierten Anionen: (Bzl4P)2[Pb3Br8], (Bzl4P)2[Pb3Br8(dmf)2], (Bzl4P)[PbBr3], (Bzl4P)2[PbBr4] und (Bzl4P)4[Pb2Br6][PbBr4]

Bromoplumbates with One‐dimensional Polymeric and Isolated Anions: (Bzl₄P)₂[Pb₃Br₈], (Bzl₄P)₂[Pb₃Br₈(dmf)₂], (Bzl₄P)[PbBr₃], (Bzl₄P)₂[PbBr₄], and (Bzl₄P)₄[Pb₂Br₆][PbBr₄] PbBr₂ reacts with LiBr and (Bzl₄P)(PF₆) (Bzl = CH₂C₆H₅) in acetone to form a series of bromoplumbate complexes with compositions and structures depending on the conditions of reaction and crystallization. While the anions in (Bzl₄P)₂[Pb₃Br₈] ( 1 ) and (Bzl₄P)[PbBr₃] ( 2 ) are one‐dimensional polymers with penta‐ and hexacoordinated Pb atoms, the metal atoms in the mono‐ and dinuclear complex anions of (Bzl₄P)₂[PbBr₄] · 2acetone ( 3 · 2acetone) and (Bzl₄P)₄[Pb₂Br₆][PbBr₄] ( 4 ) bind to four bromo ligands. From DMF as a solvent (Bzl₄P)₂[Pb₃Br₈(dmf)₂] ( 1 b ) crystallizes with the same bromoplumbate structure as in 1 a , but with dmf ligands occupying the coordination sites vacant in 1 a . Upon radiation of compound 3 with ultraviolet light greenish yellow photoluminescence (emssion maximum at 547 nm) is observed. Crystallographic details see “Inhaltsübersicht”.     

The reactions of Ir(CO)Cl(PPh3)2 with HSnPh3

A reinvestigation of the reaction of Ir(CO)Cl(PPh₃)₂, 1 with HSnPh₃ has revealed that the oxidative-addition product Ir(CO)Cl(PPh₃)₂(H)(SnPh₃), 2 has the H and SnPh₃ ligands in cis-related coordination sites. Compound 2 reacts with a second equivalent of HSnPh₃ by a Cl for H ligand exchange to yield the new compound H₂Ir(CO)(SnPh₃)(PPh₃)₂, 3. Compound 3 contains two cis- related hydride ligands. Under an atmosphere of CO, 1 reacts with HSnPh₃ to replace the Cl ligand with SnPh₃ and one of the PPh₃ ligands with a CO ligand and also adds a second equivalent of CO to yield the 5-coordinate complex Ir(CO)₃(SnPh₃)(PPh₃), 4. Compound 4 reacts with HSnPh₃ by loss of CO and oxidative addition of the Sn-H bond to yield the 6-coordinate complex HIr(CO)₂(SnPh₃)₂(PPh₃), 5 that contains two trans-positioned SnPh₃ ligands.     

Neue Komplexe des Titans mit silylierten Aminoiminophosphoran- und Sulfodiimidliganden

New Complexes of Titanium with Silylated Aminoiminophosphorane and Sulfodiimide Ligands TiCl₄ forms a 1 : 1 adduct with S(NSiMe₃)₂ to give compound 1 and with Me₂S(NSiMe₃)₂ compound 2 , respectively. The reaction of TiCl₄ with Ph₂S(NSiMe₃)₂ yields the disubstituted compound Ph₂S(NTiCl₃)₂X₄THF 3 which crystallizes in space group P1 . Reaction of TiCl₄ with (Me₃Si)₂NPPh₂NPPh₂NSiMe₃ leads to an exchange of one silyl group with a TiCl₃ moiety. In this molecule the Ti-atom is only four-coordinated. The compound crystallizes in the space group P2₁/c. No chelate complexes are formed by reactions of CpTiCl₃, Cp*TiCl₃ and Cp*TiF₃ with Ph₂P(NSiMe₃)₂H, this is shown by X-ray structural analysis of Cp*TiCl₂NPPh₂NHSiMe₃ 6 . Crystals of 6 are obtained in space group P1 .     

Metallothermische Reduktion der Tribromide und -iodide von Thulium und Ytterbium mit Alkalimetallen

Metallothermic Reduction of the Tribromides and -iodides of Thulium and Ytterbium with Alkali Metals Metallothermic reduction of the trihalides MX, (M = Tm, Yb; X = Br, I) with equimolar amounts of alkali metal (A = Li? Cs; 700–800°C, 7 d, tantalum capsules) results in the formation of the dihalides MX, (MI, with the Cd1,-type of structure, MBr, with the SrI₂- or α-PbO₂-type of structure) in the case of lithium and sodium. With A = K, Rb, Cs variants of the perovskitetype structure with the composition AMX, are obtained. They crystallize with the undistorted cubic CaTiO₃-type (CsYbBr₃), with the tetragonal NaNbO₃-11-type (CsTmBr₃) or with the orthorhombic GdFeO₃-type (CsMI₃, RbMX₃ and KMBr₃). In KTmI, and KYbI₃, corner- and edge-connected [MI₆] octahedra form layers which are connected via K⁺ in analogy to a stuffed PuBr_3? or the FeUS₃-type structure (orthorhombic, Cmcm). Single crystals of Rb₄YbI₆ are obtained as a by product upon the reduction of YbI₃ with rubidium. According to their K₄CdCl₆-type structure (trigonal, R3 c), isolated [YbI₆] octahedra are the main structural feature.     

Bleaching of kraft pulp with commercial xylanases

The perform ance of commercial xylanases in totally chlorine-free bleaching of kraft pulp from conifer was tested with Pulpzyme HC (Novo Nordisk) and Cartazyme NS-10 (Sandoz/Clariant), at 500 U/kg of dry pulp, respectively. The treatment with Pulpzyme (X_p) or Cartazyme (X_c) has been combined with stages of bleaching using: oxygen (O), sulfuric acid (A), and extraction with hydrogen peroxide (E_op). The following sequences have been tested: OXpAE_op, OXcAE_op, XpOAE_op, XcOAE_op and OAE_op, Kraft pulp bleached at the Klabin industrial plant using the sequence, CEH (chlorine, alkaline extreaction, and hypochlorination) was, used for comparison. The following average values were obtained: 1. Kappa number: OX_pAE_op, 4.8; OX_cAE_op, 4.9; XpOAE_op, 5.0; XcOAE_op, 4.9; OAE_op, 5.6, and CEH, 1.9; 2. Brightness (% ISO values): OX_pAE_op, 68.4; OX_cAE_op, 70.1; X_pOAE_op, 67.9; X_cOAE_op, 26.9; X_pOAE_op, 23.4; X_cOAE_op, 23.1; OAE_op, 25.4, and CEH, 25.2. Pulps that were treated with xylanases, before or affer the delignification with oxygen, have shown reduced kappa number and higher brightness than the pulp OAE_op, Enzyme treatment before delignification with oxygen reduces pulp viscosity. Brightness obtained for pulp produced with bleaching sequences containing the enzymatic treatment, when compared with the control, CEH, shows that the xylanases enhance the action of the bleaching agents.     

Darstellung und Eigenschaften von 3-(N,N-Dimethylamino)propyl-Verbindungen des Thalliums

Preparation and Properties of 3-(N,N-Dimethylamino)propyl Thallium Compounds TlCl₃ reacts with Me₂NCH₂CH₂CH₂Li in molar ratio 1:2 with formation of (Me₂NCH₂CH₂CH₂)₂TlCl ( 1 ) which can be transfered with MeLi into (Me₂NCH₂CH₂CH₂)₂TlMe ( 2 ) and with excess of Me₂NCH₂CH₂CH₂Li into (Me₂NCH₂CH₂CH₂)₃Tl ( 3 ) respectively. Comproportionation of 1 with TlCl₃ yields rather instable Me₂NCH₂CH₂CH₂TlCl₂ ( 4 ) from which Me₂NCH₂CH₂CH₂TlMe₂ ( 5 ) can be obtained by alkylation with MeLi. 1–3 and 5 were characterized by elemental analysis, mass spectra, ¹H- and ¹³C-n.m.r. spectra.     

NaEu2Cl6 und Na0,75Eu2Cl6: Gemischtvalente Chloride des Europiums mit Natrium

NaEu₂Cl₆ and Na_0.75Eu₂Cl₆: Mixed Valent Chlorides of Europium with Sodium The reaction of Na₂EuCl₅ with Eu metal in sealed gold tubes yields blue single crystals of NaEu₂Cl₆. It crystallizes with the hexagonal crystal system (space group P6₃/m) with a = 755.74(8) pm, c = 429.81(5) pm, Z = 1; the structure is closely related to the UCl₃-type. Green single crystals of Na_0.75Eu₂Cl₆ were first obtained as a by-product in the synthesis of Na₂EuCl₅ in evacuated silica tubes and may be prepared by reduction of EuCl₃ with sodium. Na_0.75Eu₂Cl₆ crystallizes isotypic to NaEu₂Cl₆ with a = 753.69(11) pm and c = 416.3(2) pm.     

Eine einfache Synthese von Tetrabromsilan

A Simple Synthesis of Tetrabromosilane We report on a synthesis of SiBr₄ by reacting C₆H₅SiBr₃ with HBr/AlBr₃ to give a nearly quantitative yield. We start from C₆H₅SiCl₃ which gives C₆H₅SiH₃ with LiAlH₄ and further on C₆H₅SiBr₃ with Br₂.     

Synthese und Kristallstrukturen von (PPh4)2[As2Se4Cl12] und (PPh4)2[As2Se4Br12]

Synthesis and Crystal Structures of (PPh₄)₂[As₂Se₄Cl₁₂] and (PPh₄)₂[As₂Se₄Br₁₂] The reaction of PPh₄Cl and As₂Se₃ with SOCl₂ or with chlorine in dichloromethane affords (PPh₄)₂[As₂Se₄Cl₁₂] with good yields. From PPh₄Br, As₂Se₃ and bromine the corresponding bromo compound was obtained. According to the X-ray crystal structure determinations both compounds are isotypic, crystallizing in the space group of P1 . In the anions two Se₂X₂ molecules are linked with two X^? ions forming an Se₄X₂ ring in chair conformation. Each X^?-ion is associated with an additional AsX₃ molecule (X = Cl, Br).     

Über das Dimethyl(n-propyl)phenylammoniumtriiodid n-PrMe2PhNI3 und die Reihe der Dimethyl(isopropyl)phenylammoniumpolyiodide i-PrMe2PhNIx mit x = 3, 5, 7, 8, 9

Studies of Polyhalides. 35. On the Dimethyl(n-propyl)phenylammoniumtriiodide n-PrMe₂PhNI₃ and on the Series of Dimethyl(isopropyl)phenylammoniumpolyiodides i-PrMe₂PhNI_x with x = 3, 5, 7, 8, and 9 The new compounds n-PrMe₂PhNI₃ and i-PrMe₂PhNI_x with x = 3, 5, 7, 8 and 9 have been prepared by reaction of iodine I₂ with n-PrMe₂PhNI in EtOH and with i-PrMe₂PhNI in MeOH respectively. The crystal structures have been determined by single crystal X-ray diffraction methods. The triiodide n-PrMe₂PhNI₃ has a layerlike structure with alternating anionic and cationic layers. The similar, but not isotypic triiodide i-PrMe₂PhNI₃ may be described as a layerlike packing of asymmetric anions and tetraedral cations, too. The structure of the pentaiodide i-PrMe₂PhNI₅ consists of zig-zag like iodide-diiodine chains with additional iodine molecules attached to the iodide ions in trans position. The pentaiodide part of the heptaiodide ion in i-PrMe₂PhNI₇ forms meanderlike iodide-bis(diiodine) chains also with additional iodine molecules in trans position. The structure of the hexadecaiodide ion I₁₆^2– in the octaiodide i-PrMe₂PhNI₈ contains fourteen-membered rings, which are catenated by iodine molecules and linked to layers with ten- and two types of fourteen membered rings as meshes. The anionic iodine part of the enneaiodide i-PrMe₂PhNI₉ contains fourteen-membered rings, too, which are tied up by two iodine molecules forming in addition ten membered rings which are lined up alternately.     

Der Transport von VO2 mit Cl2 und HCl + Cl2 und der Einfluß des O2-Bodenkörpergleichgewichtsdruckes auf den Transport

The Chemical Transport of VO₂ with Cl₂ and HCl + Cl₂ and the Influence of the O₂-Coexistence Equilibrium Pressure on the Transport Behaviour The transport behaviour of VO₂ with Cl₂, HCl, and Cl₂ was calculated and compared with the experimental results. VO₂ with the upper phase boundary transports with HCl and HCl + Cl₂ from the colder to the hotter zone, VO₂ of the lower phase boundary does not transport with HCl. The composition of the deposited VO₂ is near the upper boundary oxygen richer than in the start space. VO₂ does not transport with Cl₂.     

Ethylene/propylene copolymers with vanadium-based catalysts: Cocatalyst effect

Ethylene/propylene copolymers were obtained with vanadium-based catalysts. Different aluminium alkyls were employed as cocatalyst: Al(C₂H₅)₂Cl/promoter, Al(i-C₄H₉)₃, Al(n-C₆H₁₃)₃. and Al(n-C₈H₁₇)₃. The influence of the cocatalyst on the molecular weight, the molecular weight distribution and the microstructure of the copolymers was investigated through GPC, DSC, ¹³C–NMR analysis and fractionation. AIR₃ afforded a polymerization activity that was much higher with respect to Al(C₂H₅)₂Cl/nBPCC, but with the latter cocatalyst system copolymers were obtained with a more homogeneous distribution of the monomers and the absence of crystallinity. A comparison with ethylene/propylene copolymers obtained with a V(Acac)₃/Al(C₂H₅)₂Cl/promoter and with a high-yield Ti-based catalyst is also presented.     

Metallothermische Reduktion des Tribromids und -iodids von Dysprosium mit Alkalimetallen

Metallothermic Reduction of the Tribromide and -iodide of Dysprosium with Alkali Metals Metallothermic reduction (900–1000°C, 2–3 d, tantalum capsules) of DyX₃ (X = Br, I) with alkali metals (A = Li? Cs) results in the case of lithium and sodium (except for the system DyBr₃/Li) in the formation of the dihalides DyX₂ (DyI₂ with the CdCl₂-type, DyBr₂ with the SrI₂-type of structure). The reduction of DyI₃ with potassium leads to K_1.71DyI₄ which crystallizes hexagonally with a = 1 446.7(2) pm and c = 473.3(1) pm, space group P6 2m (Z = 3). In K_1.71DyI₄, [DyI₆]-octahedra are edge-connected forming chains along [001] that are linked via K⁺. With A = K, Rb, Cs, variants of the perovskite-type of structure with the composition ADyX₃ are obtained. They crystallize with the tetragonal NaNbO₃-II-type (CsDyBr₃) or with the orthorhombic GdFeO₃-type of structure (KDyBr₃, RbDyX₃, CsDyI₃).     

Phosphoraneiminato Complexes of Manganese and Cobalt with Heterocubane Structure

The phosphoraneiminato complexes [MnBr(NPEt₃)]₄ ( 1 ) and [M₄Br₅{NP(NMe₂)₃}₃] with M = Mn ( 2 ) and M = Co ( 3 ) are prepared by melting reactions from the anhydrous metal dibromides with the silylated phosphaneimines Me₃SiNPR₃ (R = Et, NMe₂) in the presence of potassium fluoride. All complexes are characterized by crystal structure analyses. 1 forms an only slightly distorted Mn₄N₄ heterocubane skeleton with an approximate T_d symmetry and short Mn…Mn distances of average 295.7 pm. In the structures of 2 and 3 one μ₃-NPEt₃ ligand of 1 is replaced by one bromine atom with μ₃-function. This leads to the novel heterocubane type M₄N₃Br with approximate C₃ symmetry. The deformation of the cubic skeleton leads to metal-metal distances of different lengths, i. e. 292.7 and 323.6 pm in 2 and 274.4 and 306.2 pm in 3 . Temperature dependent magnetic susceptibility measurements between 300 and 5 K on 1 have shown that strong antiferromagnetic coupling exists between the Mn(II) ions with S = 5/2, with a large negative Weiss constant of Θ = –694 K.     

High‐Performance Polymers for Membrane CO2/N2 Separation

This Concept examines strategies to design advanced polymers with high CO₂ permeability and high CO₂/N₂ selectivity, which are the key to the success of membrane technology for CO₂ capture from fossil fuel‐fired power plants. Specifically, polymers with enhanced CO₂ solubility and thus CO₂/N₂ selectivity are designed by incorporating CO₂‐philic groups in polymers such as poly(ethylene oxide)‐containing polymers and poly(ionic liquids); polymers with enhanced CO₂ diffusivity and thus CO₂ permeability are designed with contorted rigid polymer chains to obtain high free volume, such as polymers with intrinsic microporosity and thermally rearranged polymers. The underlying rationales for materials design are discussed and polymers with promising CO₂/N₂ separation properties for CO₂ capture from flue gas are highlighted.     

Effect of nucleating agents on the crystallization of Li<Subscript>2</Subscript>O-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-SiO<Subscript>2</Subscript> system glass

The processes of nucleation of Li₂O-Al₂O₃-SiO₂ glasses with TiO₂ and TiO₂+ZrO₂ as nucleating agents were discussed. The DTA peak temperature and DTA peak height shown a strong dependence on the nucleation temperature in the glass with TiO₂, while in the glass with TiO₂+ZrO₂ this tendency was small. The optimum nucleation temperatures were 745 and 760°C for two glasses. It suggested that with TiO₂+ZrO₂ as nucleating agents, the crystallization had lower sensitivity for nucleation temperature, and the glass had higher nucleation efficiency than with TiO₂.     

Sulfinylimine: Wichtige neue Bausteine zur Entwicklung der Chemie der Polysulfanmono- und -disulfonsäuren

Sulfinylimines: Important Building Blocks for Developing the Polysulfanemonoand -disulfonic Acid Chemistry Besides hydrolysis of perfluoroorganosulfanesulfinylimines in closed systems, reactions of R_fS_xCl with K₂S₂O₅ or M₂S₂O₃ are also productive methods for the preparation of perfluoroorganosulfanemonosulfonates. The free acid CF₃SSSO₃H is made by treating the potassium salt with a strong acidic cation resin. It is unstable and shows a pK_s-value of approx. –0,5 providing an acidity comparable with polyphosphoric acids. Metathetical reactions of the potassium salts with [(C₆H₅)₄M]Cl (M = P, As) or [R₄N][ClO₄] (R = n-C₃H₇, n-C₄H₉) respectively lead to well crystallized salts. Single crystals are used for x-ray structure analysis. These prove the polysulfanesulfon-moiety to be present in these molecules. Sulfur-sulfur-bonds can also be evidenced by chlorolysis reactions. Not only with Cl₂ but also with SCl₂ R_fS_xCl or R_fS_x+1Cl and ClSO₂OM are formed respectively. In this way CF₃SSSCl is prepared for the first time. The reaction of CF₃SeBr and K₂S₂O₅ provides K[CF₃SeSO₃] which is unstable and decomposes to CF₃SeSeCF₃, K₂S₂O₆, SO₂ and KBr. When S₂Cl₂ is reacted with (CH₃)₃SiNSO besides the main product S₂(NSO)₂ also minor amounts of S_x(NSO)₂ (x = 3, 4, 5) are formed. While hydrolysis of S₂(NSO)₂ leads quantitively to (NH₄)₂S₄O₆, a mixture of ammoniumpolysulfanedisulfonates are obtained from S_x(NSO)₂ which could not be separated. It is demonstrated that chemical reactivity is dominated by disproportionation of S₂(NSO)₂ into S(NSO)₂ and sulfur. Additonal sulfinylimines are obtained by metathesis of XNSO (X = Cl, Br) and AgSCN or AgSeCN respectively. The structures of S₂(NSO)₂ and OSNSCN are established by x-ray methods. By spectroscopical evidence it is shown that OSNSeCN is isostructured with OSNSCN.     

Metallothermische Reduktion des Tribromids und -iodids von Neodym mit Alkalimetallen

Metallothermic Reduction of the Tribromide and -iodide of Neodymium with Alkali Metals Metallothermic reduction (700–800°C, 2–3d, tantalum capsules) of NdX₃ (X = Br, I) with an equimolar amount of alkali metal (A = Li? Rb) results in the case of lithium and sodium (except for the system Li/NdBr₃) in the formation of the dihalides NdX₂ (NdBr₂ with the PbCl₂-type, NdI₂ with the SrBr₂-type of structure). With A = K and Rb, KNd₂Br₅, RbNd₂Br₅, RbNd₂I₅ and “K₈Nd₇I₂₅” are obtained. The first three crystallize with the monoclinic TlPb₂Cl₅-type (space group P2₁/c), the latter with the orthorhombic K₂PrCl₅-type of structure (space group Pnma) containing both Nd³⁺ and Nd²⁺.