Über Oxostannate(II). III. K2Sn2O3, Rb2Sn2O3 und Cs2Sn2O3 – ein Vergleich

On Oxostannates(II). III. K₂Sn₂0₃, Rb₂Sn₂0₃, and Cs₂Sn₂O₃ – a Comparison Hitherto unknown Rb₂Sn₂O₃ has been obtained by heating of mixtures of binary oxides [RbO_0.48 + SnO, Rb:Sn = 1.1:1, Al₂O₃?cylinders, Ar] as deep yellow powder or deep yellow single crystals. It is isotypic to K₂Sn₂O₃, R3 m-D with a = 6.086 Å, c = 15.101 Å, Z = 3, d_calc = 4.69, d_obs = 4.64 g X cm^?3. For 260 hkl it is R = 5.2₇% and R_w = 5.0₉% (MoKα, 4-circle diffractometer data). The structure of K₂Sn₂O₃ and Rb₂Sn₂O₃ is compared with that of Cs₂Sn₂O₃. For both types Effektive Coordination Numbers, ECoN, and the Madelung Part of Lattice Energy, MAPLE, have been calculated.     

Über quaternäre Oxoplumbate(IV). Zur Kenntnis von Rb2Li14[Pb3O14] und Cs2Li14[Pb3O14]

On Quaternary Oxoplumbates(IV). On the Knowledge of Rb₂Li₁₄[Pb₃O₁₄] and Cs₂Li₁₄[Pb₃O₁₄] For the first time, Rb₂Li₁₄[Pb₃O₁₄] and Cs₂Li₁₄[Pb₃O₁₄] have been prepared by heating of mixtures of Li₂O, β-?PbO₂”? and Rb₂PbO₃, Cs₂PbO₃ respectively with Li:Pb:A = 14:3:2, (A = Rb, Cs). [Ag-cylinders, sealed under vacuum in Duran-glass ampoule, 590 and 550°C, 40 d, powder (650°C, 200 d, single crystals of Rb₂Li₁₄[Pb₃O₁₄])]. Rb₂Li₁₄[Pb₃O₁₄] is nearly colourless with ivory nuance, Cs₂Li₁₄[Pb₃O₁₄] is pale yellow. According to powder and single crystal investigations, both are isotypic with K₂Li₁₄[Pb₃O₁₄]. Structure refinement of Rb₂Li₁₄[Pb₃O₁₄]: 1015 symmetry independent reflexions, four-circle-diffraktometer PW 1100 (Fa. Philips), ω-scan, MoKα, R = 5.73%, R_W = 5.33%, absorption not considered, space group Immm with a = 1284.71(9), b = 793.90(4), c = 727,35(5) pm, d_x-ray = 4.99 g · cm^?3, d_pyc = 5.01 g · cm^?3, Z = 2. Cs₂Li₁₄[Pb₃O₁₄]: a = 1295.28(12), b = 796.69(8), c = 732.44(7) pm, d_x-ray = 5.31 g · cm^?3, d_pyc = 5.28 g · cm^?3, Z = 2. The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Effective Ionic Radii, MEFIR, are calculated.     

Über Oxostannate(II). I. Zur Kenntnis von K2Sn2O3

On Oxostannates(II). I. Information on K₂Sn₂O₃ Hitherto unknown K₂Sn₂O₃ was obtained by heating mixtures of binary Oxides [KO_0.48 + SnO, K:Sn = 1.1:1] under Argon [Al₂O₃ cylinders, 550°C, 24 h or 7 d] as yellow powder or brownish-yellow single crystals, respectively. It crystallizes trigonal-rhombohedral in R3m—D, with a = 6.00₁ Å, c = 14.32₇ Å, Z = 3, d_rö = 4.05 and d_pyk = 3.98 gcm^?3, positions are given in text, R = 2.1₁% for 219 hkl (MoKα, 4-circle diffractometer data).     

“Fragmentierung” und “Aggregation” bei Bleioxiden Über das Oligooxoplumbat(IV) K2Li6[Pb2O8]

“Fragmentation” and “Aggregation” on Lead Oxides. On the Oligooxoplumbate(IV) K₂Li₆[Pb₂O₈] For the first time, the dinuclear Oxoplumbate(IV) K₂Li₆[Pb₂O₈] has been prepared as transparent colourless single crystals by heating mixtures of K₂PbO₃, Li₂O, and “PbO₂” with K:Li:Pb = 1:3:1 e. g. [Ag-cylinders, sealed under vacuum in Supremax-glass ampoule, 660°C, 120 d]. The structure determination verifies the space group P1 with a = 6.9720(9), b = 5.9252(6), c = 5.9312(7) Å, α = 88.05(1)°, β = 107.94(1)°, γ = 107.30(1)°; d_x = 4.95 g · cm^?3, d_pyk = 4.91 g · cm^?3; Z = 1, [2107 symmetry independent hkl, fourcircle-diffractometer Philips PW 1100, ω—2Θ—scan, MoKα, R = 5.07%, R_w = 4.59%, absorption not considered]. The structure is characterized by the group [Pb₂O₈] — two edge connected (equatorial/apical) trigonal bipyramids — that is observed for the first time. Several ways of synthesis are given. The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Effective Ionic Radii, MEFIR, are calculated.     

Darstellung und Kristallstruktur von Cs4SnO3

Preparation and Crystal Structure of Cs₄SnO₃ Crystals of Cs₄SnO₃ were synthesized by reaction of SnO with elemental Cs. The compound crystallizes with the triclinic spacegroup P1 with lattice constants a = 737.61(9) pm, b = 1171.3(1) pm, c = 1199.2(1) pm, α = 66.08(3)°, β = 80.88(2)°, γ = 82.28(3)° and Z = 4. The crystal structure exhibits isolated stannate(II) ions [Sn^IIO₃]^4– of ψ-tetrahedral form. Whereas a new structure type is present, there is a close relationship with the structures of the Cs stanntates and plumbates(IV).     

Die Kristallstruktur von Cs2S. mit einer Bemerkung über Cs2Se,Cs2Te,Rb2Se und Rb2Te

The Crystal Structure of Cs₂S and a Remark about Cs₂Se, Cs₂Te, Rb₂Se, and Rb₂Te Cs₂S crystallizes orthorhombic, a = 8.57₁, b = 5.38₃, c = 10.3₉ Å, Z = 4, d_rö = 4.13, d_pyk = 4.19 g · cm^?3, D–Pnma with \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {{\rm Cs}}\limits^|,\mathop {{\rm Cs}}\limits^\parallel $\end{document} and S in 4(c) each, for parameter see text. It is R = 10,4% for 202 of 222 possible reflexes. There is a sequence of S^2? corresponding to the hexagonal closest packing of sphares. Cs occupies half of “tetrahedron” and all “octahedron vacancies”; the deviation of \documentclass{article}\pagestyle{empty}\begin{document}$ \mathop {{\rm Cs}}\limits^|, $\end{document} in ?oktahedron vacancies”? is noticeable. Effective Coordination Numbers, ECoN, and the Madelung Part of Lattice Energy, MAPLE, are calculated and discussed.     

Neue Oxozincate der Alkalimetalle: Rb2[ZnO2] und Cs2[ZnO2]

New Oxozineates of Alkali Metals: Rb₂[ZnO₂] and Cs₂[ZnO₂] Colorless single crystals of the hitherto unknown Rb₂[ZnO₂] (a = 9.55₈, b = 6.33₅, c = 15.91 Å, β = 118.6°, z = 8, d_pyk = 4.11, d_rö = 4.21 g · cm^?3) and Cs₂[ZnO₂] (a = 9.85₁, b = 6.61₉, c = 16.26 Å, β = 116.8°) have been prepared, which crystallize monoclinic, P2₁/c – D. (For parameters see text.) Unexpected there are “isolated” groups [Zn₄O₈]. Half of the Zn atoms exhibit the unusual coordination number 3 towards O^2?. The Madelung Part of Lattice Energy, MAPLE, and the Effective Coordination Number, ECoN, the latter by means of Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.     

Zur Kenntnis von K4PbO4 und Rb4PbO4

On K₄PbO₄ and Rb₄PbO₄ For the first time single crystals of K₄[PbO₄] have been prepared by heating K₄PbO₃ in O₂. The structure has been refined [K₄[PbO₄]: 3029 I₀(hkl), four circle diffractometer PW 1100, ω-scan, MoKα, R = 6.73%, R_w = 6.64%, P1 ; a = 658.62(15), b = 658.41(12), c = 986.64(21) pm, α = 79.74(2)°, β = 108.45(2)°, γ = 112.49(2)°, d_x = 3.79 g · cm^?3, d_pyk = 3.78 g · cm^?3, Z = 2; Rb₄[PbO₄]: a = 686.94(18), b = 684.43(18), c = 1020.73(21) pm, α = 79.28(2)°, β = 108.40(2)°, γ = 113.02(2)°, d_x = 4.87 g · cm^?3, d_pyk = 4.85 g · cm^?3, Z = 2, (from Rb₂PbO₃ and Rb₂O)]. Both compounds are isotypic with K₄SnO₄. The Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated.     

Über Oxostannate(II). V. Na4[SnO3] – das erste Oxostannat(II) mit „Inselstruktur”︁

On Oxostannates(II). V. Na₄[SnO₃] – The First Oxostannate (II) with Island Structure The new oxid Na₄SnO₃ (yellow, transparant single crystals) has been prepared by heating of mixtures of: 1. NaO_0.45 and SnO (Na:Sn²⁺ = 4.1:1; Ag-cylinders; 600–730°C, 7–66 d); 2. NaO_0.45′ SnO₂ and Sn^±0 (Na:Sn⁴⁺:Sn^±0 = 8.2:1:1; Ag-cylinders; 650–680°C, 2–66 d); 3. NaO_0.45′ Na₂SnO₃ and Sn^±0 (Na:Na₂SnO₃:Sn^±0 = 6.1:1:1; Ag-cylinders; 650–670°C, 5 d). Na₄SnO₃:804 I₀(hkl); four circle diffractometer PW 1100; ω-scan; MoKα; R = 5.14%; R_w = 4.64%; monoclin, Cc? C; a = 582.77(11), b = 1667.44(24), c = 589.42(10) pm, β = 110.187(13)°; d_x = 3.20 g/cm³; d_pyk = 3.19 g/cm³; Z = 4; parameter look for text. It is a NaCl-variant with systemathical blanks of the anion part and “isolated” groups of [SnO₃]. \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm N}\mathop {\rm a}\limits^{\rm 1} $\end{document} has the uncommon coordination number 2. The Effective Coordination Numbers, ECoN, the Mean Fictive Ionic Radii, MEFIR, and the Madelung Part of Lattice Energy, MAPLE, are calculated. The structure is described using ?Erweiterte Schlegeldiagramme”?.     

Über quaternäre Oxowolframate (VI) Na6Li2[W2O10] - ein Diwolframat

On Quaternary Oxotungstates (VI). Na₆Li₂[W₂O₁₀] — a Ditungstate For the first time, Na₆Li₂[W₂O₁₀] has been prepared by annealing mixtures of WO₃, Na₂O and Li₂O with W:Na:Li = 1:3:1 [closed Pt-tube in quartz-glass ampoule, 840°C, 60 d (single crystals)]. The colourless crystals are of squatted shape. The structure determination [1813/I₀(h kl), four-cycle diffractometer PW 1100 (Fa. Philips), ω-scan, AgK_α, R = 8.32%, absorption not considered] confirms the space group P1 with a = 784.66(11), b = 602.53(7) c, = 563.81(11) pm α = 106.784(14)°, β = 114.548(14)°, γ = 91.082(13)°, Z = 2, d_x = 4.92 g · cm^?3, d^pyk = 4.85 g · cm^?3. The structure may be described as a distorted derivative of the NaCl-type. The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.     

Neue Oxoterbate(IV) mit Lithium Rb2Li14[Tb3O14] und Li6Tb2O7

New Oxoterbates(IV) with Lithium: On Rb₂Li₁₄[Tb₃O₁₄] and Li₆Tb₂O₇ For the first time we prepared Rb₂Li₁₄[Tb₃O₁₄] as yellow single crystals from Li₈TbO₆ and Rb₂O (Tb:Rb = 1:2) [Ag-cylinder, 500°C, 30 d, then Au-tube, 700°C, 27 d]. The structure refinement [652 I₀ (h kl), four circle diffractometer Philips PW 1100, ω-scan, MoKα, R = 4.69%, R_w = 3.24%, absorption considered, Immm with a = 1 283.07(10), b = 790.87(7), c = 736.87(7)pm, Z = 2, d_x = 4.30 g · cm^?3] confirms that it is isotypic with K₂Li₁₄[Pb₃O₁₄]. Furthermore we got for the first time Li₆Tb₂O₇ as a bright yellow compound from Li₂O₂ and “Tb₄O₇*” [(Li:Tb = 3.4:1), Au-ube, 750°C, 13 d (powder), 850°C 22 d (single crystals)] and by thermal decomposition of Rb₂Li₁₄[Tb₃O₁₄] (Au-tube, 850°C, 25 d). Powder and single crystal data [1 327 I₀ (h kl), four circle diffractometer PW 1100, ω-scan, AgKα, R = 9.38%, R_w = 5.23%, absorption not considered, P2₁/a, a = 1 056.30(10), b = 613.50(4), c = 546.56(5) pm, β = 109.668(7)°, Z = 2, d_x = 4.67 g · cm^?3 d_pyc = 4.53 g · cm^?3] reveal a new type of structure that may be deduced by the NaCl-type of structure. The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.     

Dynamic computer simulations of Cs incorporation in Si during low‐energy (0.2–3 keV) irradiation

The incorporation of Cs atoms in silicon was investigated by dynamic computer simulations using the Monte‐Carlo code T‐DYN that takes into account the gradual change of the target composition due to the Cs irradiation. The implantation of Cs atoms at normal incidence was studied for four energies (0.2, 0.5, 1, and 3 keV) and three different Cs surface‐binding energies U_Cs (0.4, 0.8, and 2.4 eV). The total implantation fluences were 2 × 10¹⁷ Cs cm^?2 for 0.2 keV, 1.5 × 10¹⁷ Cs cm^?2 for 0.5 keV, and 1 × 10¹⁷ Cs cm^?2 for 1 and 3 keV. At these values, a stationary state has been reached. The steady‐state Cs‐surface concentrations exhibit a pronounced dependence both on impact energy and U_Cs, varying between ～1 (at 0.2 keV and U_Cs = 2.4 eV) and ～0.13 (3 keV and U_Cs = 0.4 eV). Under equilibrium, the partial sputtering yield of Si, Y_Si, experiences little influence of U_Cs, but varies with the Cs energy: at U_Cs = 0.8 eV from 0.09 to 1.0 Si atoms/Cs projectile. For all irradiation conditions a strongly preferential sputtering of Cs atoms as compared to Si atoms is found, increasing from 1.8 (at 3 keV and U_Cs = 2.4 eV) to 13.3 (at 0.2 keV and U_Cs = 0.4 eV). Preferential sputtering of Cs increases with decreasing irradiation energy and decreasing U_Cs. Copyright © 2008 John Wiley & Sons, Ltd.     

Synthese und Kristallstruktur des Fluorid‐ino‐Oxosilicats Cs2YFSi4O10

Synthesis and Crystal Structure of the Fluoride ino‐Oxosilicate Cs₂YFSi₄O₁₀ The novel fluoride oxosilicate Cs₂YFSi₄O₁₀ could be synthesized by the reaction of Y₂O₃, YF₃ and SiO₂ in the stoichiometric ratio 2 : 5 : 3 with an excess of CsF as fluxing agent in gastight sealed platinum ampoules within seventeen days at 700 °C. Single crystals of Cs₂YFSi₄O₁₀ appear as colourless, transparent and water‐resistant needles. The characteristic building unit of Cs₂YFSi₄O₁₀ (orthorhombic, Pnma (no. 62), a = 2239.75(9), b = 884.52(4), c = 1198.61(5) pm; Z = 8) comprises infinite tubular chains of vertex‐condensed [SiO₄]^4? tetrahedra along [010] consisting of eight‐membered half‐open cube shaped silicate cages. The four crystallographically different Si⁴⁺ cations all reside in general sites 8d with Si–O distances from 157 to 165 pm. Because of the rigid structure of this oxosilicate chain the bridging Si–O–Si angles vary extremely between 128 and 167°. The crystallographically unique Y³⁺ cation (in general site 8d as well) is surrounded by four O^2? and two F^? anions (d(Y–O) = 221–225 pm, d(Y–F) = 222 pm). These slightly distorted trans‐[YO₄F₂]^7? octahedra are linked via both apical F^? anions by vertex‐sharing to infinite chains along [010] (?(Y–F–Y) = 169°, ?(F–Y–F) = 177°). Each of these chains connects via terminal O^2? anions to three neighbouring oxosilicate chains to build up a corner‐shared, three‐dimensional framework. The resulting hexagonal and octagonal channels along [010] are occupied by the four crystallographically different Cs⁺ cations being ten‐, twelve‐, thirteen‐ and fourteenfold coordinated by O^2? and F^? anions (viz.[(Cs1)O₁₀]^19?, [(Cs2)O₁₀F₂]^21?, [(Cs3)O₁₂F]^24?, and [(Cs4)O₁₂F₂]^25? with d(Cs–O) = 309–390 pm and d(Cs–F) = 360–371 pm, respectively).     

Alkalioxoargentate(I). Über Na3AgO2

Oxoargentates(I) of Alkali Metals. On Na₃AgO₂ Na₃AgO₂ has been prepared anew (light pale-yellow powder samples; clear transparent single crystals). It crystallizes orthorhombic (space group Ibam) with a = 5.46₃, b = 10.92₆, c = 5.92₆ Å, Z = 4, d_rö = 3.94 g X cm^?3, d_pyk = 3.89 g X cm^?3; parameters are given in the text. The structure of Na₃AgO₂, marked by linear “dumb-bells” [O? Ag? O], d(Ag→O) = 2.09 Å is a novel variant of Na₂O. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, have been calculated and are discussed.     

Neues über Oxouranate: Über α-Li6UO6. Mit einer Bemerkung über β-Li6UO6

New Investigations about Oxo Uranates: On α-Li₆UO₆. With a Remark about β-Li₆UO₆ The crystal structure of transparent, bright yellow single crystals of α-Li₆UO₆ has been determined. [a = 838.07(5), c = 738.34(7) pm; d_pyk = 4.02, d_x = 4.17 g · cm^?3; space group R3 ; Z = 3; R = 3.17%, R_w = 3.06%; 408 symmetry independent I₀(hkl); AgKα fourcircle diffractometer Philips PW 1100]. The structure is dominated by a threedimensional framwork of “hollow spaces”, built up by 12 O^2? (and 12 Li⁺). The Madelung Part of Lattice Energy, MAPLE, is calculated and discussed.     

Zur Kenntnis der Oxopalladate der Alkalimetalle [1]

On Oxopalladates of Alkali Metals According to X-ray data of single crystals there are: Na₂PdO₂ (yellow rod-shaped crystals) orthorhombic, a = 3.07₇, b = 10.35₉, c = 8.35₁ Å, Z = 4; d_x = 4.60, d_pyk = 4.6₃ g · cm^?3. ?K₂PdO₃”? (black square prism) orthorhombic, a = 6.20₂, b = 9.21₉, c = 4× 11.37₂ = 45.4₈ Å, Z = 24, d_x = 3.60, d_pyk = 3.5₀ g · cm^?3, and ?K₆PdO₄”? (orange square prism) orthorhombic (pseudotetragonal), a = b = 12.36₈, c = 13.59₃ Å, Z = 8, D₂⁴—P2₁2₁2₁. ?Rb₂PdO₃”? (black) is isostructural (Guinier data) to ?K₂PdO₃”?, a = 7.35₄, b = 9.60₅, c = 11.58₆ Å, d_x = 4.58, d_pyk = 4.4₇ g · cm^?3. Na₂PdO₃ exists in another reddish brown form, isostructural to Li₂MnO₃ (C_2h⁶—C2/c), a = 5.37₄, b = 9.30₉, c = 10.78₉ Å, β = 99.5°, Z = 8, d_x = 5.00, d_pyk = 4.7₃ g · cm^?3.     

Polysulfonylamine. CLXIII [1] Kristallstrukturen von Metall‐di(methansulfonyl)amiden. 12 [1] Das orthorhombische Doppelsalz Na2Cs2[(CH3SO2)2N]4·3H2O: Ein dreidimensionales Koordinationspolymer aus (Caesium‐Anion‐Wasser)‐Schichten und intercalierten Natriumionen

Polysulfonylamines. CLXIII. Crystal Structures of Metal Di(methanesulfonyl)amides. 12. The Orthorhombic Double Salt Na₂Cs₂[(CH₃SO₂)₂N]₄·3H₂O: A Three‐Dimensional Coordination Polymer Built up from Cesium‐Anion‐Water Layers and Intercalated Sodium Ions The packing arrangement of the three‐dimensional coordination polymer Na₂Cs₂[(MeSO₂)₂N]₄·3H₂O (orthorhombic, space group Pna2₁, Z′ = 1) is in some respects similar to that of the previously reported sodium‐potassium double salt Na₂K₂[(MeSO₂)₂N]₄·4H₂O (tetragonal, P4₃2₁2, Z′ = 1/2). In the present structure, four multidentately coordinating independent anions, three independent aquo ligands and two types of cesium cation form monolayer substructures that are associated in pairs to form double layers via a Cs(1)—H₂O—Cs(2) motif, thus conferring upon each Cs⁺ an irregular O₈N₂ environment drawn from two N, O‐chelating anions, two O, O‐chelating anions and two water molecules. Half of the sodium ions occupy pseudo‐inversion centres situated between the double layers and have an octahedral O₆ coordination built up from four anions and two water molecules, whereas the remaining Na⁺ are intercalated within the double layers in a square‐pyramidal and pseudo‐C₂ symmetric O₅ environment provided by four anions and the water molecule of the Cs—H₂O—Cs motif. The net effect is that each of the four independent anions forms bonds to two Cs⁺ and two Na⁺, two independent water molecules are involved in Cs—H₂O—Na motifs, and the third water molecule acts as a μ₃‐bridging ligand for two Cs⁺ and one Na⁺. The crystal cohesion is reinforced by a three‐dimensional network of conventional O—H···O=S and weak C—H···O=S/N hydrogen bonds.     

Vibrational Spectra of Cluster Anions. 2. Vibrational Spectra of Compounds with the Cluster Anions [E4]4−: M4E4 (M = K,Rb, Cs; E = Ge,Sn) and β‐Na4Sn4

Vibrational spectra of the compounds M₄E₄ (M = K, Rb, Cs; E = Ge, Sn) and of β‐Na₄Sn₄ with the cluster anions [E₄]^4? were analysed based on the point group of isolated tetrahedranide units. The lower individual symmetry of the anions in the real structure being more patterned and complex primarily affects the spectra of the tetrahedro‐tetragermanides. ν₃(F₂) clearly splits both in Raman and IR and in the case of K₄Sn₄ only in IR. Rb₄Sn₄ and Cs₄Sn₄ exhibit very simple spectra with three bands in Raman and one band in IR. The breathing mode ν₁(A₁) for the quasi isolated [E₄]^4? cluster appears only in the Raman spectrum and is hardly influenced by the structural environment and by the nature of the alkali metal cations: ν₁(A₁) = 274 cm^?1 ([Ge₄]^4?) and 183‐187 cm^?1 ([Sn₄]^4?), respectively. The calculated valence force constants f_d(E–E) are: [Ge₄]^4? : f_d = 0.89 Ncm^?1 ( K ), 0.87 Ncm^?1 ( Rb ), 0.86 Ncm^?1 ( Cs ) and [Sn₄]^4? : 0.67 Ncm^?1 ( Na ), 0.66 Ncm^?1 ( K ), 0.67 Ncm^?1 ( Rb ), 0.68 Ncm^?1 ( Cs ). Both, the frequencies and the force constants fit well into the range previously reported.     

Kinetics of the reactions of acenaphthene and acenaphthylene and structurally-related aromatic compounds with OH and NO3 radicals,N2O5 and O3 at 296 ± 2 K

The kinetics of the atmospherically important gas-phase reactions of acenaphthene and acenaphthylene with OH and NO₃ radicals, O₃ and N₂O₅ have been investigated at 296 ± 2 K. In addition, rate constants have been determined for the reactions of OH and NO₃ radicals with tetralin and styrene, and for the reactions of NO₃ radicals and/or N₂O₅ with naphthalene, 1- and 2-methylnaphthalene, 2,3-dimethylnaphthalene, toluene, toluene-α,α,α-d₃ and toluene-d₈. The rate constants obtained (in cm³ molecule^?1 s^?1 units) at 296 ± 2 K were: for the reactions of O₃; acenaphthene, <5 × 10^?19 and acenaphthylene, ca. 5.5 × 10^?16; for the OH radical reactions (determined using a relative rate method); acenaphthene, (1.03 ± 0.13) × 10^?10; acenaphthylene, (1.10 ± 0.11) × 10^?10; tetralin, (3.43 ± 0.06) × 10^?11 and styrene, (5.87 ± 0.15) × 10^?11; for the reactions of NO₃ (also determined using a relative rate method); acenaphthene, (4.6 ± 2.6) × 10^?13; acenaphthylene, (5.4 ± 0.8) × 10^?12; tetralin, (8.6 ± 1.3) × 10^?15; styrene, (1.51 ± 0.20) × 10^?13; toluene, (7.8 ± 1.5) × 10^?17; toluene-α,α,α-d₃, (3.8 ± 0.9) × 10^?17 and toluene-d₈, (3.4 ± 1.9) × 10^?17. The aromatic compounds which were observed to react with N₂O₅ and the rate constants derived were (in cm³ molecule^?1 s^?1 units): acenaphthene, 5.5 × 10^?17; naphthalene, 1.1 × 10^?17; 1-methylnaphthalene, 2.3 × 10^?17; 2-methylnaphthalene, 3.6 × 10^?17 and 2,3-dimethylnaphthalene, 5.3 × 10^?17. These data for naphthylene and the alkylnaphthalenes are in good agreement with our previous absolute and relative N₂O₅ reaction rate constants, and show that the NO₃ radical reactions with aromatic compounds proceed by overall H-atom abstraction from substituent-XH bonds (where X = C or O), or by NO₃ radical addition to unsaturated substituent groups while the N₂O₅ reactions only occur for aromatic compounds containing two or more fused six-membered aromatic rings.     

Das erste KEGGIN-Anion mit tetraedrischer. Kupfer(II)—Sauerstoff-Koordination: [α-Cu0,4(H2)0,6O4W12O36]6−

The First KEGGIN-Anion with Tetrahedral Coordination of Copper(II)-Oxygen: [α-Cu_0,4(H₂)_0.6O₄W₁₂O₃₆]^6? The solution of the Cu^II-containing heteropolyanion was prepared starting from an aqueous solution of Na₂WO₄, adjusting to pH 5–6 by adding slowly a solution of Cu(NO₃)₂ in HNO₃. The addition of the corresponding amount of N(CH₃)₄Br to the concentrated solution led to the crystallization of the greenish-yellow mixed crystals (TMA)₆[α-Cu_0.4(H₂)_0.6O₄W₁₂O₃₆] · 9 H₂O. After repeated recrystallization it has been investigated by chemical, spectroscopic (IR/Raman, UV, ¹⁸³W/¹H-NMR, ESR) and X-ray diffraction methods (monoclinic; space group P2₁; a = 13.117(4), b = 21.466(4), c = 13.223(3) Å, β = 91.60°; Z = 2; D_c = 3.041 g · cm^?3; R = 8.0%). The distances of the four “tetrahedral” oxygen atoms to the position (0, 0, 0) range from 1.67 to 1.93 Å. The alternative occupation of the central KEGGIN position with copper(II) and two protons, respectively, accounts for the different distances. The prepared solid solution represents the first example for the tetrahedral copper(II)-oxygen coordination in any heteropolyanion compound.