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1.
About Cs2Li2[GeO4] By heating of a well-ground mixture of the binary oxides CsO0.55, Li2O and GeO2 (Cs:Li:Ge=2,6:2,2:1; Ni-tube; 600 °C; 49d) we got single crystals of Cs2Li2[GeO4] for the first time. Cs2Li2[GeO4] is isotypic to Rb2Li2[MO4] [M = Si, Ti, Ge] [2] and Cs2Li2[MO4] (M = Si, Ti) [3]: according to this Cs2Li2[GeO4] crystallizes triclinic, in the spacegroup P1 with a = 968.7(4) pm, b = 586.0(2) pm, c = 571.4(2) pm, α = 92.71(4)°, β = 110.95(3)° and γ = 94.34(4)° (Guinier-Simon data), Z = 2. The structure was determined by four-circle diffractometer data (Ag? Kα ; 2381 Io(hkl); R = 8,4%; Rw = 5.0%), parameters see text. Further the Madelung Part of Lattice Energy (MAPLE), Effective Coordination Numbers (ECoN) and the Mean Fictive Ionic Radii (MEFIR), have been calculated. 相似文献
2.
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%, RW = 5.33%, absorption not considered, space group Immm with a = 1284.71(9), b = 793.90(4), c = 727,35(5) pm, dx-ray = 4.99 g · cm?3, dpyc = 5.01 g · cm?3, Z = 2. Cs2Li14[Pb3O14]: a = 1295.28(12), b = 796.69(8), c = 732.44(7) pm, dx-ray = 5.31 g · cm?3, dpyc = 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. 相似文献
3.
New Oxoferrates (III). Na2Li3[FeO4] and K2Li3[FeO4] . Na2Li3[FeO4] and K2Li3[FeO4] (transparent, pink or light yellow single crystals) have been prepared by heating mixtures of the oxides (Na:Li:Fe = 2.2:3.3:1; Ag-tube, 720°C, 27 d or K:Li:Fe = 2.2:3.3:1; analogous, 700°C, 40 d). Na2Li3[FeO4] is isotypic with Na2Li3[GaO4] (a = 832.2(1), b = 796.0(1), c = 656.3(1)pm, Pnnm) and K2Li3[FeO4] with K2Li3[GaO4] (a = 557.7(1), b = 880.6(1), c = 1101.8(2)pm, β = 111.51(2)°, P21/c). Four cycle diffractometer data: MoKα, 525 out of 686 I0(hkl), R = 9.36%, Rw = 5.97% or 1424 out of 1424 I0(hkl), R = 8.45%, Rw = 5.66%. Parameters see text. The structures are characterized by calculations of the Madelung Part of Lattice Energy, MAPLE. The Effective Coordination Numbers, ECoN, which are calculated by means of Mean Fictive Ionic Radii, MEFIR, are compared with the analogous gallates. 相似文献
4.
Inhaltsübersicht. Erstmals wurden klar durchscheinende, orange-farbene Einkristalle von Cs2Li14[Tb3O14] aus Cs2TbO3 und Li2O (Tb: Li = 1:5) dargestellt [550°C, 21 d, verschlossenes AuRohr]. Es liegt der K2Li14[Pb3O14]-Typ vor [Vierkreisdiffraktometerdaten, PW 1100, MoKä-Strahlung, 660 Io(hkl), R = 4,8%, Rw = 3,4%, Immm, a = 1293,5(8), b = 792,6(3), c = 740,4(3) pm, Z = 2, drö = 4,65]. Ebenfalls neu wurde K2Li14[Zr3O14] in Form farbloser Einkristalle durch Tempern inniger Gemenge von K2O, Li2O und ZrO2 (K: Li: Zr = 1:4:1,5) dargestellt [900°C, 14 d, geschlossene Ni-Bombe] und röntgenographisch untersucht. Die Strukturverfeinerung [612 Io(hkl), Vierkreisdiffraktometerdaten, PW 1100, MoKα-Strahlung, R = 5,9%, Rw = 5,3%, Immm, a = 1244,6, b = 776,4, c = 724,3 pm, Z = 2] bestätigt die Isotypie mit K2Li14[Pb3O14]. Der Madelunganteil der Gitterenergie, MAPLE, Effektive Koordinationszahlen, ECoN, diese über Mittlere Effektive Ionenradien, MEFIR, wurden berechnet. Für die nun bekannten Vertreter dieses Typs wurde ein Isotypievergleich vorgenommen. New Compounds of the K2Li14[Pb3O14] Type: Cs2Li14[Tb8O14] and K2Li14[Zr3O14] For the first time Cs2Li14[Tb3O14] has been prepared as orange single crystals from Cs2TbO3 and Li2O (Tb: Li = 1:5) [550°C, 21 d, sealed Au-Tube]. Structure Refinement [four-circle diffractometer data, PW 1100, MoKα radiation, 660 Io(hkl), R = 4.8%, Rw = 3.4%, Immm, a = 1293.5(8), b = 792.6(3), c = 740.4(3) pm, Z = 2, drö = 4.65] confirms isotypy with K2Li14[Pb3O14]. K2Li14[Zr3O14] has also been prepared as colorless single crystals from K2O, Li2O, and ZrO2 (K: Li: Zr = 1:4:1.5), [900°C, 14 d, closed Ni-cylinder] and investigated by x-ray [612 Io(hkl), four-circle diffractometer data, PW 1100, MoKα radiation, R = 5.9%, Rw = 5.3%, Immm, a = 1244.6, b = 776.4, c = 724.3 pm, Z = 2]. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, the latter derived from Mean Effective Fictive Ionic Radii, MEFIR, are calculated. A detailed comparison of the structures is carried out. 相似文献
5.
Preparation of Crystal Structure of K6[Al2O6] and Rb6[Al2O6] Colourless single crystals of K6[Al2O6] have been prepared from intimate mixtures of KAlO2 and K2O (550°C, 90 d). The structure determination from four-circle diffractometer data (MoKα , 742 Io(hkl), R = 2.2%, Rw = 2.1%) confirms the space group C2/m with Z = 2; a = 698.25 pm, b = 1 103.54 pm, c = 646.49 pm, β = 102.49°. Colourless single crystals of hitherto unknown Rb6[Al2O6] have been prepared from intimate mixtures of RbAlO2 and Rb2O (520°C, 120 d). The structure determination from four-circle diffractometer data (MoKα , 1 240 Io(hkl)) results in the residual values R = 7.2%, Rw = 4.9%; space group C2/m; a = 725.92 pm, b = 1 143.33 pm, c = 678.06 pm, β = 104.05°; Z = 2. K6[Al2O6] and Rb6[Al2O6] are isostructural with K6[Fe2O6]. A characteristic structure unit is the anion [Al2O6]6? consisting of two edge-sharing [AlO4] tetrahedra. Effective Coordination Numbers (ECoN), Mean Fictive Ionic Radii (MEFIR), the Madelung Part of Lattice Energy (MAPLE) and the Charge Distribution (CHARDI) are calculated and discussed. 相似文献
6.
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%, Rw = 3.24%, absorption considered, Immm with a = 1 283.07(10), b = 790.87(7), c = 736.87(7)pm, Z = 2, dx = 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%, Rw = 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, dx = 4.67 g · cm?3 dpyc = 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. 相似文献
7.
A New Cobaltate with Isolated Anion Structure: Li6[CoO4] For the first time transparent, blue single crystals of Li6[CoO4] have been prepared (Li2O/Na2O/?CoO”? (Li:Na:Co = 1.3:1.3:1), Co-tube, 580°C, 22 d). Corresponding to Li6□CoO; it is an ordered variant of the Li2O-type of structure: P42/nmc; a = 653.6(1) pm, c = 465.4(1) pm; Z = 2; dx = 2.75 g cm?3, dpyk = 2.71 g cm?3 (4-circle-diffractometer-data (PW 1100), AgKα; 230 from 936 I0(hkl); R = 9.58%, RW = 5.25%). Parameters see text. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed. The magnetic properties are measured in the temperature range of 14–297 K. 相似文献
8.
Angela Mller 《无机化学与普通化学杂志》1997,623(11):1685-1692
Synthesis, Crystal Structures, and Absorption Spectra of the New “Cupriosilicates”: K6[CuSi2O8] and Rb4[CuSi2O7] K6[CuSi2O8] and Rb4[CuSi2O7] were obtained by annealing intimate mixtures of K2O and Rb2O, respectively, CuO and SiO2 in sealed Ag cylinders at 500°C as transparent greenish-blue single crystals. The structure solution (IPDS-data Mo Kα; K6[CuSi2O8]: 1292 F2(hkl), R1 = 0.059; wR2 = 0.103 and Rb4[CuSi2O7]: 763 F2(hkl), R1 = 0.049; wR2 = 0.114) confirms the space group P1 for both compounds. K6[CuSi2O8]: a = 619.4(2); b = 665.5(2); c = 753.0(2) pm; α = 83.66(3); β = 87.71(3); γ = 70.19(3)°; Z = 1. Rb4[CuSi2O7]: a = 631.9(9); b = 707.5(10); c = 715.2(6) pm; α = 114.2(1); β = 100.7(1); γ = 107.9(1)°; Z = 1. The Madelung Part of the Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these calculated via Mean Effective Ionic Radii, MEFIR, are given. The absorption spectra of K6[CuSi2O8] and Rb4[CuSi2O7] are discussed in terms of the Angular Overlap Model, AOM. 相似文献
9.
New Metal Oxides with Doubles of Tetrahedra as Building Units: Rb6[Tl2O6] and Cs6[In2O6] We prepared the hitherto unknown Rb6[Tl2O6] and Cs6[In2O6] by heating mixtures of Tl2O3 and RbO0.60 (Rb:Tl = 3.5:1) as well as In2O3 and CsO0.53 (Cs:In = 3.5:1) as single crystals [closed Ag-cylinder, 650°C, 14 d]. The single crystals of Rb6[Tl2O6] are yellow, those of Cs6[In2O6] pale yellow, all transparent and rude. The new type of structure was elucidated by 4-circle-diffractometer (PW 1100) data. Rb6[Tl2O6]: P21/a; a = 1145,7(3), b = 713,3(1), c = 783,9(2) pm, β = 93,73° (2), Z = 2; Ag–Kα, 2100 out of 2531 I0(hkl), R = 9,6% and Rw = 8,9%. Cs6[In2O6]: P21/a; a = 1178,5(4), b = 730,7(2), c = 816,3(2) pm, β = 95,38° (3), Z = 2; Mo–Kα, 1584 out of 2032 I0(hkl), R = 9,25%, and Rw = 8,44%. The Madelung Part of Lattice Energy, MAPLE, is calculated and discussed. 相似文献
10.
New Alkalioxoarsenates (V). On Rb2Li[AsO4] and Cs2Li[AsO4] By heating of well-grounded mixtures of the binary oxides (A2O, Li2O2, and As2O3; A : Li : As = 2 : 1 : 1; Ni-tube, 550°C, 21 d; A = Rb, Cs) colourless single crystals of Rb2Li[AsO4] and Cs2Li[AsO4] were obtained for the first time. These new orthoarsenates(V) crystalize orthorhombic (space group C mc21? C, No. 36) with Z = 4. As expected they are isotypic with the according orthovanadates(V) [2] A2Li[VO4], A = Rb, Cs. The lattice constants of Rb2Li[AsO4]: a = 582.1(4) pm, b = 1171.1(7) pm, c = 792.4(5) pm and Cs2Li[AsO4]: a = 596.4(2) pm, b = 1223.4(2) pm, c = 819.7(3) pm were taken from Guinier-Simon powder data. The structure was determined by four-circle-diffractometer data [Siemens AED II, MoKα , 6290 I0 (hkl), R = 3.5%, Rw = 3.2% to Rb2Li[AsO4]; 3518 I0 (hkl), R = 2.8%, Rw = 2.6% to Cs2Li[AsO4]; parameters see text]. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these calculated via Mean Fictive Ionic Radii, MEFIR, as well as charge distribution CHARDI are calculated and discussed. 相似文献
11.
New Oxides with the “Butterfly-Motive”: Rb6[Fe2O5] and K6[Fe2O5] Rb6[Fe2O5] and K6[Fe2O5] were obtained for the first time by annealing intimate mixtures of “Rb6CdO4” with CdO (molar ratio 1 : 1.1) and KO0.48 with CdO (molar ratio 5.9 : 1) respectively in closed Fe-cylinders. Determination and refinement of the crystalstructure confirms the space group C2/m (four-circle-diffractometer data). Rb6[Fe2O5]: Ag Kα , 720 out of 1220 Io(hkl), R = 9.68%, Rw = 6.09%; a = 718.9pm, b = 1183.1 pm, c = 695.4pm, β = 95.05°, Z = 2; K6[Fe2O5]: MoKα , 1214 Out of 12141o(hkl), R = 3.20070, Rw = 2.48%, a = 691.21 pm, b = 1142.78pm, c = 665.50pm, β = 93.82°, Z = 2. The binuclear unit [O2FeOFeO2]6? already known to be planar with oxoferrates(II) now was observed to be angular here and closely related to Na6[Be2O5]. 相似文献
12.
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 CsO0.52 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. 相似文献
13.
A New Oxozincate: Li6[ZnO4] Colourless single crystals of Li6[ZnO4] are formed by reaction of Li2O and ZnO [(Li2O:ZnO = 3.3:1, 700°C 50 d), Space group P42/nmc, Z = 2, a = 652.76 pm, c = 465.09 pm R = 2.6%, Rw = 2.1%, 173 symmetry independend I0(hkl), MoK]. The crystal structure has been determined. 相似文献
14.
Li4Sr2[Cr2N6]: A Hexanitridodichromate(V) The quaternary hexanitridodichromate(V) Li4Sr2[Cr2N6] was obtained by reaction of the metals with flowing nitrogen at 900 °C as black‐shining crystals with a platy habit. The crystal structure was determined by X‐ray single crystal methods (orthorhombic, Pbca; a = 914.0 pm, b = 735.4 pm, c = 1053.6 pm; Z = 4). The compound contains isolated complex anions [Cr2N6]8— consisting of two tetrahedra CrN4 sharing a common edge. The distance Cr—Cr in the complex anion is 249.7 pm. The analysis of the Electron Localization Function (ELF) indicates bonding interactions Cr—Cr. Strontium is in a sixfold (distorted octahedral), Lithium in a distorted tetrahedral ([3+1]) coordination by nitrogen. According to measurements of the magnetic susceptibility the compound is diamagnetic. 相似文献
15.
Oxidation of Intermetallic Phases: K4{Na2[Tl2O6]} from NaTl and K2O2 The hitherto unknown K4{Na2[Tl2O6]} was prepared in form of transparent, yellow single crystals from NaTl and KO1,08 (molar ratio 1:1.3; sealed Ag-cylinder; 450°C, 30 d). The structure determination (four-circle diffractometer, MoKα, 1 280 out of 1 523 Io(hkl), R = 5.75%, Rw = 4.58%) confirms the space group P21/c with a = 641.3 pm, b = 691.1 pm, c = 1188.5 pm, β = 95.69° and Z = 2. As characteristic building units of the structure there are doubles of tetrahedra of [Tl2O6] and [Na2O6]. The compound is isotypic with Cs6[In2O6] and Rb6[Tl2O6]. The Madelung Part of Lattice Energy, MAPLE, the Mean Fictive Ionic Radii, MEFIR, Effective Coordination Numbers, ECoN, and Charge Distribution, CHARDI, are calculated. 相似文献
16.
New Oxogallates of Alkaline Metals: On K6[Ga2O6] and Rb6[Ga2O6] as well as Na3GaO3 and Cs6[Ga2O6] Due to powder and single crystal data K6[Ga2O6] a = 7.099; b = 11.116; c = 6.484 Å; ß = 101.66° and Rb6[Ga2O6] a = 7.393; b = 11.475; c = 6.798 Å; ß = 103.5° crystallize isotypic with K6[Fe2O6]; space group C2/m-C32h; As well has been prepared the hitherto unknown Na3GaO3 a = 11.48, b = 10.82, c = 6.13 Å, space-group Imcm or I2cm Z = 8; and Cs6[Ga2O6] a = 7.26, b = 12.1, c = 7.68 Å, ß = 105°, Z = 4, space-group P21/a. 相似文献
17.
The First Binuclear Oxoferrate(II): ?Cs2K4[O2FeOFeO2]”? For the first time ?Cs2K4[Fe2O5]”? was obtained by annealing intimate mixtures of Cs2O, K2O, and CsFeO2 (molar ratio Cs : K : CsFeO2 1.3 : 2.1 : 1) in a closed Fe-cylinder (74 d; 470°C) in the form of red single crystals. The structure determination (four-circle diffractometer, MoKα , 760 out of 857 Io(h kl); R = 5.8%, Rw = 4.6%) confirms the space group C2/m; a = 707.4, b = 1138.5, c = 699.7 pm, β = 91.76°, Z = 2. Essential part of the structure is the binuclear, planar [O(1)2Fe? O(2)? FeO(1)2]6? group which is for the first time observed with oxoferrates(II). Despite different space groups the crystal structure is related to that of Rb2Na4[Co2O5]. 相似文献
18.
Thio- and Selenomercurates(II). K6[HgS4], K6[HgSe4], Rb6[HgS4] and Rb6[HgSe4] We prepared by annealing intimate mixture of pure samples of K2S, K2Se, Rb2S, and Rb2Se with HgS or HgSe [360–380°C, 7d, Duran-glass-seal with Argon] with hexagonal Na6ZnO4 isotypic new mercurates: K6[HgS4] [bright citronic yellow a = 9.985, c = 7.652 Å], K6[HgSe4] [light orange yellow a = 10.36, c = 7.883 Å], Rb6[HgS4] [bright yellow a = 10.34, c = 7.942 Å], Rb6[HgSe4] [orange-red a = 10.72, c = 8.192 Å]. The crystal structure of K6 Hgs4 is elucidated by using diffractometer data of single crystals: P63mc, C46v, it is R = 6.6% for 304 reflexes [h k o–h k 4, anisotropic refinement MoKα]; for position and parameters see text drö = 2.835, dpyk = 2.99 g · cm?3. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, are calculated and discussed. 相似文献
19.
An Oxostannate of a New Structure Type: Cs4[SnO4] In order to prepare Cs3LiSnO4 by heating of a well ground mixture of the binary oxides [CsO0.67, Li2O, SnO2; Cs:Li:Sn = 3.3:1.0:1.0; 450°C; 28 d; Ni-tube] colourless, monoclinic single crystals of Cs4[SnO4] have been yielded for the first time: space group P21/c with a = 1180.8 pm. b = 728.2 pm, c = 1166,7 pm, β = 111.79°, Z = 4. The crystal structure was solved by fourcycle-diffractometer data [Siemens AED2, 2299 from 2708 I0(hkl), R = 7.0%, Rw = 5.6%], parameters see text. Characteristic for the complicated structure are “isolated” [SnO4]4? tetrahedra. Mean Fictive Ionic Radii, MEFIR, Effective Coordination Numbers, ECoN and the Madelung Part of Lattice Energy, MAPLE, have been calculated. 相似文献
20.
Reactions of Uranium Pentabromide. Crystal Structures of PPh4[UBr6], PPh4[UBr6] · 2CCl4, (PPh4)2[UBr6] · 4CH3CN, and (PPh4)2[UO2Br4] · 2CH2Cl2 PPh4[UBr6] and PPh4[UBr6] · 2CCl4 were obtained from UBr5 · CH3CN and tetraphenylphosphonium bromide in dichloromethane, the latter being precipitated by CCl4. Their crystal structures were determined by X-ray diffraction. PPh4[UBr6]: 2101 observed reflexions, R = 0.090, space group C2/c, Z = 4, a = 2315.5, b = 695.0, c = 1805.2 pm, β = 96.38°. PPh4[UBr6] · 2CCl4: 2973 reflexions, R = 0.074, space group P21/c, Z = 4, a = 1111.5, b = 2114.2, c = 1718.7 pm, β = 95.42°. Hydrogen sulfide reduces uranium pentabromide to uranium tetrabromide. Upon evaporation, bromide is evolved from solutions of UBr5 with 1 or more then 3 mol equivalents of acetonitrile in dichlormethane yielding UBr4 · CH3CN and UBr4 · 3CH3CN, respectively. These react with PPh4Br in acetonitrile affording (PPh4)2[UBr6] · 4CH3CN, the crystal structure of which was determined: 2663 reflexions, R = 0.050, space group P21/c, Z = 2, a = 981.8, b = 2010.1, c = 1549.3 pm, β = 98.79°. By reduction of uranium pentabromide with tetraethylammonium hydrogen sulfide in dichloromethane (NEt4)2[U2Br10] was obtained; (PPh4)2[U2Br10] formed from UBr4 and PPh4Br in CH2Cl2. Both compounds are extremely sensitive towards moisture and oxygen. The crystal structure of the oxydation product of the latter compound, (PPh4)2[U02Br4]· 2 CH2Cl2, was determined: 2163 reflexions, R = 0.083, space group C2/c, Z = 4, a = 2006.3, b = 1320.6, c = 2042,5 pm, β = 98.78°. Mean values for the UBr bond lengths in the octahedral anions are 266.2 pm for UBr6-, 276.7 pm for UBr62? and 282.5 pm for UO2Br42? 相似文献