Tartrate der TypenLn 2(H2 T)3·xH2O undLnH5 T 2·xH2O einiger Seltenerdmetalle

The following compounds were isolated and more closely studied by means of thermal analysis, X-ray scattering and IR absorption spectra and determination of solubilities: Pr₂(H₂ T)₃ · 6 H₂O, Nd₂(H₂ T)₃ · 6 H₂O, Sm₂(H₂ T)₃ · 5 H₂O, Gd₂(H₂ T)₃ · 5 H₂O, Tb₂(H₂ T)₃ · 5 H₂O, Dy₂(H₂ T)₃ · 5 H₂O, Ho₂(H₂ T)₃ · 5 H₂O, Er₂(H₂ T)₃ · 5 H₂O, PrH₅ T ₂ · 2 H₂O, NdH₅ T ₂ · 2 H₂O, SmH₅ T ₂ · 2 H₂O, GdH₅ T ₂ · 3 H₂O, TbH₅ T ₂ · 3 H₂O, DyH₅ T ₂ · 3 H₂O, HoH₅ T ₂ · 3 H₂O, ErH₅ T ₂ · 3 H₂O.     

Kristallstrukturen des Sr(BrO3)2 · H2O,Ba(BrO3)2 · H2O,Ba(IO3)2 · H2O,Pb(CIO3)2 · H2O und Pb(BrO3)2 · H2O

Crystal Structure of Sr(BrO₃)₂ · H₂O, Ba(BrO₃)₂ · H₂O, Ba(IO₃)₂ · H₂O, Pb(ClO₃)₂ · H₂O, and Pb(BrO₃)₂ · H₂O The crystall structures of the isostructural halates Sr(BrO₃)₂ · H₂O, Ba(BrO₃)₂ · H₂O, Ba(IO₃)₂ · H₂O, Pb(ClO₃)₂ · H₂O, and Pb(BrO₃)₂ · H₂O were determined using X-ray single crystal data (monoclinic space group C2/c? C, Z = 4), The mean bond lengths and bond angles of the halate ions in the Ba(ClO₃)₂ · 1 H₂O-type compounds, which correspond to those of other halates, are Cl? O, 149.0, Br? O, 165.9, I? O, 180.2 pm, ClO₃^?, 106.4, BrO₃^?, 104.0, and IO₃^?, 99.6°. The structure data obtained are discussed in terms of possible orientational disorder of the water molecules, strengths of the hydrogen bonds, influence of the lead ions on the structure, and site group distortion of the halate ions.     

Zur Koordination des Aluminiums in den Calciumaluminathydraten 2 CaO · Al2O3 · 8 H2O und CaO · Al2O3 · 10 H2O

On the Coordination of Al in the Calcium Aluminate Hydrates 2 CaO · Al₂O₃ · 8 H₂O and CaO · Al₂O₃ · 10 H₂O By investigations with high-resolution ²⁷Al-NMR in solids it is shown that in the compound 2 CaO · Al₂O₃ · 8 H₂O the Al merely exist in octahedral coordination. According to this and considering its structural relationship with 4 CaO · Al₂O₃ · 19 H₂O the dicalcium aluminate hydrate is proposed to be formulated as [Ca₂Al(OH)₆][Al(OH)₃ (H₂O)₃]OH. Likewise for the compound CaO · Al₂O₃ · 10 H₂O the octahedral coordination of the Al is proved by ²⁷Al-NMR. This result corresponds with literature according to which a constitution as cyclohexaaluminate Ca₃[Al₆(OH)₂₄] · 18 H₂O is proposed.     

Rates of reaction of atomic oxygen with C2H3F,C2H3Cl,C2H3Br, 1,1-C2H2F2, and 1,2-C2H2F2

Rate constants for the reactions of atomic oxygen (O³P) with C₂H₃F, C₂H₃Cl, C₂H₃Br, 1,1-C₂H₂F₂, and 1,2-C₂H₂F₂ have been measured at 307°K using a discharge-flow system coupled to a mass spectrometer. The rate constants for these reactions are (in units of 10¹¹ cm³ mole^?1 s^?1) 2.63 ± 0.38, 5.22 ± 0.24, 4.90 ± 0.34, 2.19 ± 0.18, and 2.70 ± 0.34, respectively. For some of these reactions, the product carbonyl halides were identified.     

A study of the system CdO-SeO2-H2O at 25 and 100°C

The solubility of the system CdO-SeO₂-H₂O was studied at 25 and 100°C. The fields of crystallization of α-CdSeO₃, 3CdSeO₃·H₂SeO₃ and CdSeO₃·SeO₂ were established at 25°C. At 100°C crystallize α-CdSeO₃, 3CdSeO₃·SeO₂, 2CdSeO₃·SeO₂ and CdSeO₃·SeO₂. The compounds obtained were identified by means of chemical, X-ray and crystal-optical analysis. The mechanism of thermal dissociation of α-CdSeO₃, 3CdSeO₃·H₂SeO₃ and CdSeO₃·SeO₂ was studied. This revised version was published online in August 2006 with corrections to the Cover Date.     

Na2B2Se7, K2B2S7 und K2B2Se7: Drei Perchalkogenoborate mit neuem polymeren Anionengerüst

Na₂B₂Se₇, K₂B₂S₇, and K₂B₂Se₇: Three Perchalcogenoborates with a Novel Polymeric Anion Network Na₂B₂Se₇ (I 2/a; a = 11.863(4) Å, b = 6.703(2) Å, c = 13.811(6) Å, β = 109.41(2)°; Z = 4), K₂B₂S₇ (I 2/a; a = 11.660(2) Å, β = 6.827(1) Å, c = 12.992(3) Å, β = 106.78(3)°; Z = 4), and K₂B₂Se₇ (I 2/a; a = 12.092(4) Å, b = 7.054(2) Å, c = 13.991(5) Å, β = 107.79(3)°; Z = 4) were prepared by reaction of stoichiometric amounts of sodium selenide (potassium sulfide) with boron and sulfur or of potassium selenide and boron diselenide, respectively, at 600°C with subsequent annealing. The crystal structures consist of polymeric anion chains of composition ([B₂S₇]^2?)_n or ([B₂Se₇]^2?)_n formed by spirocyclically connected five-membered B₂S₃ (B₂Se₃) rings and six-membered B₂S₄ (B₂Se₄) rings. The nine-coordinate alkaline metal cations are situated in between.     

Syntheses,Structures, and Properties of New Quaternary Gold-Chalcogenides: K2Au2Ge2S6, K2Au2Sn2Se6, and Cs2Au2SnS4

The new compounds K₂Au₂Ge₂S₆ ( 1 ), K₂Au₂Sn₂Se₆ ( 2 ), and Cs₂Au₂SnS₄ ( 3 ) have been synthesized through direct reaction of the elements with a molten polyalkalithiogermanate(stannate) flux at 650, 550, and 400 °C, respectively. Their crystal structures have been determined by single crystal X-ray diffraction techniques. 1 crystallizes in the monoclinic space group P2₁/n with a = 10.633(2) Å, b = 11.127(2) Å, c = 11.303(2) Å, β = 115,37(3)°, V = 1208,2(3) ų and Z = 4, final R(Rw) = 0.045(0.106). 2 crystallizes in the tetragonal space group P4/mcc with a = 8.251(1) Å, c = 19.961(4) Å, V = 1358,9(4) ų and Z = 4, final R(Rw) = 0.040(0.076). 3 crystallizes in the orthorhombic space group Fddd with a = 6.143(1) Å, b = 14.296(3) Å, c = 24.578(5) Å, V = 2158.4(7) ų and Z = 4, final R(Rw) = 0.039(0.095). The structures of 1 , 2 , and 3 consist of infinite, one-dimensional anionic chains containing X₂Q₆^4– units linked by Au⁺ ions and charge balancing K⁺/Cs⁺ ions situated between the chains. All compounds were investigated with differential thermal analysis, FT-IR, and solid state UV/VIS diffuse reflectance spectroscopy.     

Absolute rate constants for the self reactions of HO2, CF3CFHO2, and CF3O2 radicals and the cross reactions of HO2 with FO2, HO2 with CF3CFHO2, and HO2 with CF3O2 at 295 K

The kinetics of the self-reactions of HO₂, CF₃CFHO₂, and CF₃O₂ radicals and the cross reactions of HO₂ with FO₂, HO₂ with CF₃CFHO₂, and HO₂ with CF₃O₂ radicals, were studied by pulse radiolysis combined with time resolved UV absorption spectroscopy at 295 K. The rate constants for these reactions were obtained by computer simulation of absorption transients monitored at 220, 230, and 240 nm. The following rate constants were obtained at 295 K and 1000 mbar total pressure of SF₆ (unit: 10⁻¹² cm³ molecule⁻¹ s⁻¹): k(HO₂+HO₂)=3.5±1.0, k(CF₃CFHO₂+CF₃CFHO₂)=3.5±0.8, k(CF₃O₂+CF₃O₂)=2.25±0.30, k(HO₂+FO₂)=9±4, k(CF₃CFHO₂+HO₂)=5.0±1.5, and k(CF₃O₂+HO₂)=4.0±2.0. In addition, the decomposition rate of CF₃CFHO radicals was estimated to be (0.2–2)×10³ s⁻¹ in 1000 mbar of SF₆. Results are discussed in the context of the atmospheric chemistry of hydrofluorocarbons. © 1997 John Wiley & Sons, Inc.     

Synthese und Struktur von [(Me2PhP)3Cl2ReN]2ReCl4, [(Me2PhP)3Cl2ReN]2ReCl4 · 2 SbCl3 und [Re(NH)Cl2(PMe2Ph)3][SbCl6]

Synthesis and Structure of [(Me₂PhP)₃Cl₂ReN]₂ReCl₄, [(Me₂PhP)₃Cl₂ReN]₂ReCl₄ · 2 SbCl₃ and [Re(NH)Cl₂(PMe₂Ph)₃][SbCl₆] The reaction of ReNCl₂(PMePh)₃ with SbCl₅ in toluene yields the trinuclear complex [(Me₂PhP)₃Cl₂Re≡N]₂ReCl₄ · 2 SbCl₃ ( 1 · 2 SbCl₃). It forms triclinic crystals with the composition 1 · 2 SbCl₃, as well as monoclinic crystals 1 · 2 SbCl₃ · 4 C₇H₈. The monoclinic crystals with the space group P2₁/c, and a = 1212.3(2), b = 2098.5(4), c = 1827.7(3) pm, β = 95.51(1)°, Z = 2, have been used for a crystal structure determination. In the centrosymmetric complex 1 two complexes ReNCl₂(PMe₂Ph)₃ coordinate with their nitrido ligands a square planar, central unit ReCl₄. The SbCl₃ molecules are coordinated by chlorine bridges to Cl atoms of 1 , and, in addition, connect the complexes 1 with each other. The SbCl₃ free compound 1 is obtained in good yield by the reaction of ReNCl₂(PMePh)₃ with ReCl₄(NCEt)₂. It crystallizes in the triclinic space group P1 with a = 1037.7(3), b = 1153.0(2), c = 1393.8(3) pm, α = 72.31(2)°, β = 74.06(2)°, γ = 67.94(2)°, and Z = 1. The bond lengths of the Re–N triple bonds are 172 pm in 1 and 170 pm in 1 · 2 SbCl₃. By the reaction of ReNCl₂(PMePh)₃ with SbCl₅ in CH₂Cl₂ the solvent is decomposed forming HCl which protonates the nitrido ligand to afford the imido complex [Re(NH)Cl₂(PMe₂Ph)₃][SbCl₆] ( 2 ) crystallizing in the monoclinic space group P2₁/n with a = 1221.4(2), b = 1358.6(2), c = 2177.3(1) pm, β = 92,72(1)° and Z = 4. The Re–N distance in the almost linear unit Re≡N–H is 169,1 pm.     

A kinetic study of the reaction of fluorine atoms with CH3F,CH3Cl,CH3Br,CF2H2, CO,CF3H,CF3CHCl2, CF3CH2F,CHF2CHF2, CF2ClCH3, CHF2CH3, and CF3CF2H at 295 ± 2 K

A variety of relative and absolute techniques have been used to measure the reactivity of fluorine atoms with a series of halogenated organic compounds and CO. The following rate constants were derived, in units of cm³ molecule^?1 s^?1: CH₃F, (3.7 ± 0.8) × 10^?11, CH₃Cl, (3.3 ± 0.7) × 10^?11; CH₃Br, (3.0 ± 0.7) × 10^?11; CF₂H₂, (4.3 ± 0.9) × 10^?12; CO, (5.5 ± 1.0) × 10^?13 (in 700 torr total pressure of N₂ diluent); CF₃H, (1.4 ± 0.4) × 10^?13; CF₃CCl₂H (HCFC-123), (1.2 ± 0.4) × 10^?12; CF₃CFH₂ (HFC-134a), (1.3 ± 0.3) × 10^?12, CHF₂CHF₂ (HFC-134), (1.0 ± 0.3) × 10^?12; CF₂ClCH₃ (HCFC-42b), (3.9 ± 0.9) × 10^?12, CF₂HCH₃ (HFC-152a), (1.7 ± 0.4) × 10^?11; and CF₃CF₂H (HFC-125), (3.5 ± 0.8) × 10^?13. Quoted errors are statistical uncertainties (2σ). For rate constants derived using relative rate techniques, an additional uncertainty has been added to account for potential systematic errors in the reference rate constants used. Experiments were performed at 295 ± 2 K. Results are discussed with respect to the previous literature data and to the interpretation of laboratory studies of the atmospheric chemistry of HCFCs and HFCs. © 1993 John Wiley & Sons, Inc.     

Kondensierte Al6‐Ringe in den Subiodiden La3Al2I2 und La2Al2I

Condensed Al₆ Rings in the Subiodides La₃Al₂I₂ and La₂Al₂I The subiodides La₃Al₂I₂ and La₂Al₂I are reported. The compounds were prepared from stoichiometric mixtures of lanthanum, aluminium, and LaI₃ under Ar atmosphere in sealed Ta ampoules at 920–950 °C and 980–1000 °C, respectively. La₃Al₂I₂ crystallizes in space group C2/m with a = 19.73(2) Å, b = 4.318(1) Å, c = 12.348(9) Å and β = 121.49(3)°, La₂Al₂I in P6₃/mmc with a = 4.3718(8) Å and c = 17.605(2) Å (isotypic with Gd₂Fe₂I). Both structures are characterized by sheets of trigonal prisms formed by the La atoms centered by aluminium, the latter being arranged in Al₆ rings. These rings are connected to chains in La₃Al₂I₂ (d_{Al(2)–Al(2)} = 2.550(4) Å and 2.615(2) Å, respectively) and layers (d_Al–Al = 2.533(1) Å) in La₂Al₂I. Both compounds are metallic conductors. The electronic structure of both compounds is discussed based on band structure calculations.     

Synthesis and structure of copper(II) trans-diaqua-bis(3-hydroxybenzoylhydrazine) nitrate dihydrate [Cu(C7H8O2N2)2(OH2)2](NO3)22H2O

Synthesis of [Cu(m-HBH)₂(OH₂)₂](NO₃)₂·2H₂O, where m-HBH = C₇H₈O₂N₂ (3-hydroxybenzoylhydrazine), is described. The structure of the compound was studied by X-ray phase analysis and IR spectroscopy; crystal data are a = 57.415(6) Å, b = 19.760(2) Å, c = 7.586(2) Å; Fdd 2, Z = 16, R(F) = 0.053. The compound consists of [Cu(m-HBH)₂(OH₂)₂]²⁺ complex cations, NO ₃ ^? anions, and two water molecules. The similarity between the IR spectra of Cu(m-HBH)₂(NO₃)₂·nH₂O and Co(m-HBH)₂(NO₃)₂·5H₂O, element analysis data, and crystal data obtained at the first stage of X-ray analysis show that the structures and compositions of these compounds are identical relative to the type of surroundings of the central atom. In contrast to the cobalt compound [Co(m-HBH)₂(OH₂)₂](NO₃)₂·3H₂O, in which the cobalt atom has a nearly regular octahedron as a coordination polyhedron, the copper(II) compound has a square bipyramid around the copper atom; c.n. is 6 = 4 + 2 (planar distances: 2.013(2) Å, 2.021(2) Å, 2.033(3) Å, 2.087(3) Å; axial distances: 2.367(3) Å, 2.374(3) Å) and lacks one crystallization water molecule.     

Untersuchung der Cokristallisation in den Systemen. Mn(OOCCH3)2-Co(OOCCH3)2-H2O,Mn(OOCCH3)2-Ni(OOCCH3)2-H2O,Mn(OOCCH3)2-Zn(OOCCH3)2-H2O bei 60°C

Investigation of Cocrystallization in the Systems Mn(OOCCH₃)₂-Co(OOCCH₃)₂-H₂O, Mn(OOCCH₃)₂-Ni(OOCCH₃)₂-H₂O, Mn(OOCCH₃)₂-Zn(OOCCH₃)₂-H₂O at 60°C The three-component systems Mn(OOCCH₃)₂-Co(OOCCH₃)₂-H₂O, Mn(OOCCH₃)₂-Ni(OOCCH₃)₂-H₂O and Mn(OOCCH₃)₂-Zn(OOCCH₃)₂-H₂O at 60°C were investigated by physio-chemical analysis. There is an interruption in the series of mixed crystals formed in the three-component systems. The inclusion of Co²⁺- and Ni²⁺ in Mn(OOCCH₃)₂ · 2 H₂O of Mn²⁺ in Co(OOCCH₃)₂ · 2 H₂O, Zn(OOCCH₃)₂ · 2 H₂O and Ni(OOCCH₃)₂ · 4 H₂O is based on isodimorphic substitution. It was found that in the system Mn(OOCCH₃)₂-Zn(OOCCH₃)₂-H₂O crystallizes Zn(OOCCH₃)₂ · Mn(OOCCH₃)₂ · 2 H₂O. It was identified by the X-ray and differential thermal analysis.     

Dinuclear Cobalt(III) Complexes Showing a Co2O2 Metallacycle

The heptadentate Schiff base H₃L reacts with cobalt(II) acetate in methanol to form the discrete dinuclear complex Co₂L(OAc)₂(OMe)(H₂O)₂ ( 1 ·2H₂O). The reaction of 1 ·2H₂O with NMe₄OH·5H₂O in methanol gives rise to displacement of the acetate by methanolate groups, yielding Co₂L(OMe)₃(H₂O) ( 2 ·1H₂O). Recrystallizations of the Schiff base, 1 ·2H₂O and 2 ·H₂O in different solvents, produce single crystals of H₃L, 1 ·2.5H₂O and 2 ·2MeOH, respectively. The crystal structures of 1 ·2.5H₂O and 2 ·2MeOH show the cobalt atoms double bridged by and endogenous phenol oxygen atom and an exogenous methanolate oxygen donor, giving rise to Co₂O₂ cores with Co···Co distances of ca. 2.87 Å.     

Die Kristallstruktur des Natriumoxohydroxoaluminathydrates Na2[Al2O3(OH)2] · 1,5 H2O

The Crystal Structure of the Sodium Oxohydroxoaluminate Hydrate Na₂[Al₂O₃(OH)₂] · 1.5 H₂O The crystal structure of the sodium oxohydroxoaluminate hydrate Na₂[Al₂O₃(OH)₂] ·s 1.5 H₂O (up to now described as Na₂O · Al₂O₃ · 2.5 H₂O and Na₂O · Al₂O₃ · 3 H₂O, respectively) was solved. The X-ray single crystal diffraction analysis (tetragonal, space group P-42₁m, a = 10.522(1) Å, c = 5.330(1) Å, Z = 4) results in a polymeric layered structure, consisting of AlO_3/2(OH) tetrahedral groups. Between these layers the Na⁺ ions are situated, which form tetrameric groups of face-linked NaO₆ octahedra. The involved O^2? ions are due to Al? O? Al bridges, Al? OH groups and water of crystallization. ²⁷Al and ²³Na MAS NMR investigations confirm the crystal structure analysis. The relations between the crystallization behaviour of the compound and the constitution of the aluminate anions in the corresponding sodium aluminate solution and in the solid, respectively, are discussed.     

Phosphaniminato-Komplexe von Titan(IV) und Titan(III). Die Kristallstrukturen von [TiCl2(OMe)(NPPh3)]2, [TiBr2(NPPh3)]2 · 3 C7H8 sowie von [Ph3PNH2]Br · CH2Cl2

Phosphorane Iminato Complexes of Titanium(IV) and Titanium(III). The Crystal Structures of [TiCl₂(OMe)(NPPh₃)]₂, [TiBr₂(NPPh₃)]₂ · 3C₇H₈, and [Ph₃PNH₂]Br · CH₂Cl₂ TiCl₃(NPPh₃) reacts with a solution of methyllithium in diethyl ether in the presence of lithiummethylate forming yellow [TiCl₂(OMe)(NPPh₃)]₂. On reaction with benzyl magnesium bromide TiCl₃(NPPh₃) in diethyl ether is converted into green [TiBr₂(NPPh₃)]₂ under reduction and ligand exchange. [TiBr₂(NPPh₃)]₂ crystallizes from toluene with three molecules C₇H₈. [Ph₃PNH₂]Br · CH₂Cl₂ originates as a side product of this reaction. The products are characterized by their i.r. spectra and by crystal structure analyses. [TiCl₂(OMe)(NPPh₃)]₂ . Space group P1 , Z = 2, structure solution with 2909 independent reflections, R = 0.063. Lattice dimensions at 20°C: a = 1005.1, b = 1044.5, c = 1068.6 pm, α = 66.98°, β = 89.35°, γ = 80.24°. The compound forms centrosymmetric dimeric molecules with μ₂-OMe bridges and five-fold coordinated titanium atoms. The (NPPh₃^?) ligand is terminally connected with a Ti = N distance of 174.8 pm and with a TiNP bond angle of 165.3°. [TiBr₂(NPPh₃)]₂ · 3 C₇H₈ . Space group P1 , Z = 2, structure solution with 5548 independent reflections, R = 0.053. Lattice dimensions at ?70°C: a = 983.3, b = 1162.7, c = 1376.5 pm, α = 100.53°, β = 110.30°, γ = 105.24°. The compound forms centrosymmetric dimeric molecules with μ₂-NPPh₃ bridges and tetrahedral coordination at the titanium atoms. With 195.9 pm the Ti–N bonds correspond with single bonds. The Ti …? Ti distance of 260.0 pm is exceptionally short. [Ph₃PNH₂]Br · CH₂Cl₂ . Space group P1 , Z = 1, structure solution with 3091 independent reflections, R = 0.049. Lattice dimensions at 20°C: a = 909.4, b = 1004.4, c = 1158.5 pm, α = 108.09°, β = 94.67°, γ = 91.92°. The bromide ions are bonded to a one-dimensional infinite network via hydrogen bridge bonds of the cation and of the dichloromethane.     

A study on the thermal stability of uranyl phosphates (UO2)3(PO4)2, (UO2)2P2O7, and UO2(PO3)2 using a static non-isothermal method

A static, non iso-thermal method is used to investigate the stability of uranyl phosphates. The resulting oxygen partial pressures can be expressed as: (UO₂)₃(PO₄)₂, (1089–1280°K) log pO₂/atm = (−18480±400)/T+(13.11±0.33)(UO₂)₂P₂O₇, (979–1130°K) log pO₂/atm = (−27460±540)/T+(24.26±0.51)UO₂(PO₃)₂, (963–1118°K) log pO₂/atm = (−25320±680)/T+(22.58±0.66).Using these results, a part of the phase diagram UO_x (x = 2 to 3) − P₂O₅ is calculated.     

Kinetics of the peroxy RFO2 radical formation in the RHF-O2-CO2 gaseous mixtures

The kinetic data on the molecular oxygen activity of CH₃CH^·, CH₃CF₂ ^· and CF₃CHF^· radicals are reported. In laboratory, these radicals were generated by pulsed (12 ns) electron beam interaction with the gaseous RHF-O₂-CO₂ mixtures containing large excess of carbon dioxide (RHF = CH₃CH₂F, CH₃CHF₂ or CH₂FCF₃). The transient product (O₃ or RFO₂ ^·) formation was monitored by the UV absorptions at 250 nm and the rate constants of Reactions (4) and (9) were obtained. The values of k ₉ diminished with increasing number of fluorine atoms in RHF molecule. For CH₃CH₂F and CH₃CHF₂ the k ₉’s were equal to (8.8–10.2)^·10⁻¹⁴cm^{3 ·}s⁻¹ and (7.3–8.4)^·10⁻¹⁴cm^{3 ·}s⁻¹, respectively, and seem to be determined for the first time. In the case of CH₂FCF₃ the obtained value of k _CF3CHF+O2 = 5.20±0.76^·10⁻¹⁴cm^{3 ·}s⁻¹ is much higher than the value published in the literature.⁴ The other determined rate constant data are comparable to the literature values.     

Oxydationsprodukte intermetallischer Phasen. III. Tieftemperaturformen von K2Sn2O3 und Rb2Sn2O3 und eine Notiz über K2Ge2O3

Oxidation Products of Intermetallic Compounds. III. Low Temperature Forms of K₂Sn₂O₃ and Rb₂Sn₂O₃ and a Notice about K₂Ge₂O₃ By controlled oxidation of KSn (at 320°C) and RbSn (at 410°C) with O₂ the hitherto unknown low temperature forms of K₂Sn₂O₃ (a = 8.4100(8) Å) and Rb₂Sn₂O₃ (a = 8.6368(8) Å) are obtained, which are isotopic with cubic K₂Pb₂O₃. Oxidation at higher temperatures (at 510–5207°C) leads to the well-known HT-forms. The Madelung Part of Lattic Energie, MAPLE, is calculated for both compounds. K₂Pb₂O₃, Rb₂Pb₂O₃, Cs₂Pb₂O₃, and Cs₂Sn₂O₃ have been prepared too by oxidation of KPb, RbPb, CsPb, and CsSn. Oxidation of KGe (at 400°C) leads to the first oxogermanate(II), K₂Ge₂O₃ (cubic a = 8.339(1) Å, isotypic with K₂Pb₂O₃) together with K₆Ge₂O₇.     

Preparation of Aluminum Alkoxides and Crystal Structures of [Al{(S)-(-)-μ-OC(H)(CH3)C(Ph)2OH}Cl2]2·2Et2O and [(μ-O(CH2)2OPh)AlMe2]2

The reaction of (S)-(-)-1, l-diphenyl-propane-1,2-diol with AlCl₃ in diethyl ether furnishes the product [Al((S)-(-)-μ₂-OC(H)(Me)C(Ph)₂OH)Cl₂]₂ 1, which decomposes slowly above 25 °C. Complex 1·2Et₂O Crystallizes in the non-centrosymmetric monoclinic space group P2₁ with a=10.591(1) Å, b=16.718(1) Å, c = 12.156(2) Å, β=99.30(2)°, V = 2124.1(3) Å₃, z = 4, R = 4.67%, Rw=4.84%, GoF=1.14. The structure of 1 shows a dimer feature, which is hydrogen bonded to two diethyl ether molecules. In the reaction of 2-phenoxyethanol with AlMe₃, the dimeric [(μ-O(CH₂)₂OPh)AlMe₂]₂ is obtained in high yield. 2 crystallizes in the monoclinic space group P2₁/c with a = 7.398(2) Å, b = 7.376(2) Å, c = 20.710(2) Å, β = 90.56(2)°, v = 1129.9(4) ų, z=4, R=5.70%, Rw=7.15%, GoF=1.59.