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1.
On Ordered Perovskites with Cationic Vacancies. IX. Compounds of the Type Sr2Sr1/4B □1/4WO6?Sr8SrB ?W4O24 (BIII ? La, Pr, Nd, Sm–Tm, Y) The compounds Sr2Sr1/4B□1/4WO6?Sr8SrB?W4O24 belong to the group of perovskites with octahedral cationic vacancies (cation/vacancy ratio (CN 6) ?:1). For the larger BIII ions (La, Pr, Nd, Sm–Dy) different ordering effects are observed. The perovskites with BIII ? Sm, Eu, Gd are polymorphic too (HT modification: higher ordered cubic perovskite (BIII ? Gd: a = 2X8.234 Å); LT modification: hexagonal perovskite stacking polytype (BIII ? Gd: a = 9.954 Å; c = 19.04 Å)). With the smaller BIII ions (Ho, Er, Tm and Y) a cubic, 1:1 ordered perovskite type is observed. 相似文献
2.
P. Khl 《无机化学与普通化学杂志》1973,401(2):121-131
The Crystal Structure of Perovskites A NiIIMVIO6. II. Sr2NiWO6 The results of an X-ray single crystal study of the perovskite Sr[NiIIWVI](6)O6, ordered in the octahedral sites, are given. While Sr[NiIITeVI](6)O6 crystallizes in a monoclinically deformed structure of the perovskite (elpasolite) type, showing a phase transition to a tetragonal lattice at 675 °K, Sr[NiIIWVI](6)O6 is tetragonal already at 298°K (space group: C; a = b = 5.559 Å; c = 7.918 Å; Z = 2). The Ni? O distances found for the tungsten compound are nearly identical with those of the tellurium perovskite. In contradiction to crystal field theory very different values of the ligand field parameter Δ (ca. 25%) are observed for these two compounds however. Obviously this effect is caused by the rather different kind of bonding within the NiO6 polyhedra in the two compounds. On the basis of the structural results the Ni? O-bonding in the two perovskites is discussed in dependence of the next nearest cationic environment. 相似文献
3.
The formation of ternary nitridometalates from the elements in the case of the systems Li—Cr, V, Mn—N leads to compounds which contain the transition metals in the highest (VV, CrVI) or a comparably high (MnV) oxidation state. In the corresponding calcium and strontium systems, the transition metals show a lower oxidation state (VIII, CrIII, MnIII). Transition metals with intermediate oxidation states (CrV, MnIV) are present in the quaternary (mixed cation) compounds Li4Sr2[CrN6], Li6Ca2[MnN6], and Li6Sr2[MnN6] (R3¯(#148), a = 585.9(3) pm, c = 1908.6(4) pm, Z = 3), as well as in the solid solution series Li6(Ca1—xSrx)2[MnN6]. 相似文献
4.
Crystal Structure and Properties of Calcium and Strontium Hexathiodiphosphate(IV), Ca2P2S6 and Sr2P2S6, with a Contribution on Ca5P8 and Pb2P2S6 Ca2P2S6 and Sr2P2S6 were prepared from metal and a mixture of red phosphorus and sulfur (molar ratio M:P:S = 1:1:3) in 2 corundum crucibles inserted in quartz ampullae under vacuum (20 d 900°C). The compounds were obtained as colourless, crystalline powders containing single crystals. They crystallize in the Sn2P2S6 (high temperature form) type structure (P21/c, Z = 2): Ca2P2S6 a = 653.2(2)pm, b = 728.1(2)pm, c = 1110.1(4)pm, β = 124.00(4)°, d = 2.50(2); Sr2P2S6 a = 664.3(2)pm, b = 755.7(3)pm, c = 1139.7(3)pm, β = 124.07(2)°, d = 2.97(2). The anions P2S have staggered confirmation and are arranged with the motif of a cubic close-packing. Sr2+ is coordinated by 8S which form a twofold face-capped trigonal prism and belong to 4P2S. Structure calculations clearly show that Pb2P2S6 also crystallizes in P21/c and not in Pc [1]. Also, Raman- and IR-spectra of Ca5P8 were recorded at 20°C. The stretching vibrations of P were assigned in analogy to those of P2S in alkaline earth hexathiodiphosphates(IV). The range of their frequencies (480 to 340 cm?1) is essentially smaller and shifted to smaller values compared with P2S in Ca2P2S6 and Sr2P2S6 (620 to 390 cm?1). The symmetry of P is not D3d but C2h as in the case of P2S. 相似文献
5.
On Perovskites A B B WVIO6 Compounds of type ABBWVIO6 can be obtained with AII ? Ba; BI ? Li, Na and BIII ? La, Nd, Sm, Gd, Y, In, Sc just as with AII ? Sr, BI ? Li and BIII ? La, Nd, Sm, Gd, Y, In (all cubic ordered perovskites). For the cubic perovskites Sr2Na0,5La0,5WO6 and Sr2Na0,5Nd0,5WO6 additional superlattice reflections are observed (a ∽ 16.4 Å). The compounds Sr2Na0,5BWO6 crystallize with BIII ? Sm, Gd in a monoclinic and with BIII ? Y, In in a rhombic distorted perovskite lattice. For the perovskites with A = Sr — dependent on ionic radii of the B ions — two different lattice types are present. 相似文献
6.
S. Kemmler-Sack 《无机化学与普通化学杂志》1981,483(12):126-139
Photoluminescence of Trivalent Rare Earths in Perovskite Stacking Polytypes Ba2La2?x RE MgW2□O12, Ba6Y2?x RE W3□O18, and Sr8SrGd2?xRE W4□O24 Rhombohedral 12 L stacking polytypes Ba2La2?xREMgW2□O12 show with RE3+ = Pr, Sm, Eu, Tb, Dy, Ho, Er, Tm; the 18 L stacking polytypes Ba6Y2?xREW3□O18 and the polymorphic perovskites Sr8SrGd2?xREW4□O24 with RE3+ = Sm, Eu, Dy, Ho, Er visible photoluminescence. The concentration dependence and the influence of the coordination number of the rare earth are reported. 相似文献
7.
Synthesis and Crystal Structure of Sr2Zn(OH)6 and Ba2Zn(OH)6 Crystallization from supersaturated sodium hydroxozincate solutions by adding solutions of alkali earth metal hydroxides yields crystals of Sr2Zn(OH)6 and Ba2Zn(OH)6. The X-ray structure determination on these crystals was successful including all hydrogen positions: Sr2Zn(OH)6: P21/n, Z = 2, a = 5.794(1) Å, b = 6.160(1) Å, c = 8.141(1) Å, b = 91.23(1)°, N(F ³° 2σ F) = 1127, N(Var.) = 53, R1/wR2 = 0.047/0.081Ba2Zn(OH)6: P21/n, Z = 2, a = 6.043(1) Å, b = 6.336(1) Å, c = 8.451(2) Å, b = 91.23(2)°, N(F ° 2σ F) = 1669, N(Var.) = 54, R1/wR2 = 0.029/0.067. Sr2Zn(OH)6 and Ba2Zn(OH)6 crystallize isotypic in a distorted Li2O structure type. Sr2+ resp. Ba2+ form a cubic primitive arrangement. Distorted octahedra of OH– around Zn2+ fill therein alternating cubic gaps in an ordered way. 相似文献
8.
A New Structure Type on the first Alkaline-Earth-Iridium-Copper Oxide: Sr3IrCuO6 Sr3IrCuO6 was prepared by solid state reactions and investigated by single crystal X-ray work (space group C – C12/c1; a = 9.300; b = 9.717; c = 6.997 Å; β = 92.15°). The so far unknown compound forms a new structure type. Typical features of the crystal structure are isolated chains of alternate IrO6 octahedra and square planar CuO4 polygones. The coordination of Sr2+ can be described as a square antiprism. 相似文献
9.
On the Atomic Distribution in Ba2SrIn2O6 with a Contribution to the Existence of the Calciumferrite-Type of Oxoindates (I) Ba2SrIn2O6 and (II) Sr0.93Ba0.07In2O4 were prepared and investigated by single crystal X-ray technique. I crystallizes with tetragonal symmetry, space group D – I4/mmm, a = 4.168; c = 21.290 Å; Z = 2; II belongs to the orthorhombic space group D – Pnma, a = 9.858; b = 3.273; c = 11.520 Å; Z = 4. I shows in respect to the formerly investigated compound BaSr2In2O6 an unexpected statistically distribution of Ba2+ and Sr2+ with the La2SrCu2O6 type. II marks the range of existence of the calciumferrite type within the alkaline earth oxoindates in direction of large radii of M2+ ions. 相似文献
10.
On Ordered Perovskites with Cationic Vacancies. X. Compounds of Type A B B □1/4MVIO6 ? A BIIB □M O24 with AII, BII = Ba, Sr, Ca and MVI = U, W Perovskites of type Ba8BIIB2III□UO24 show polymorphic phase transformations of order disorder type. An 1:1 ordered orthorhombic HT form is transformed into a higher ordered LT modification with a fourfold cell content (four formula units Ba8BIIB□U4O24), compared to cubic 1:1 ordered perovskites A2BMO6. In the series Ba8BaB□W4O24 and Sr8SrB□W4O24 different ordering phenomena are observed. In comparison with 1:1 ordered cubic perovskites A2BMO6, the cell contains eight formula units ABIIB□W4O24. The higher ordered cells with UVI and WVI are face centered, which has its origin in an ordering of cationic vacancies. 相似文献
11.
A Contribution on Sr3Nd4O9 The metastable compound Sr3Nd4O9 was prepared by high temperature reactions and investigated by X-ray single crystal methods. It crystallizes with monoclinic symmetry: a = 1147.4; b = 723.8; c = 1324.6 pm and β = 115.6°: space group C? Cs. The metal positions show a nearly statistical distribution of Sr2+ and Nd3+. The network of the polyhedrals characterizes a new structure type, which in spite of the statistical metal distribution does not belong to the high temperature X-modification of the Rare Earth sesquioxides. 相似文献
12.
Shuhong Xu Chunlei Wang Yiping Cui 《International journal of quantum chemistry》2010,110(6):1287-1294
At DFT/B3LYP/6‐31G** theoretical level, C6H and C (n = 0, ?2, and +2), C6H and C (n = 0, ±2, ±4, and ±6), C6H (n = 0–6), as well as C6H6‐A and C6‐A (A = Be, B, N, O, Mg, Al, Si, S, and Fe) structures were investigated. Comparing NICS values of C6H and C (n = 0, ?2, and +2), we discovered that C6H, C6H were antiaromatic, and C6H6, C6, C, C had aromaticity with negative NICS values. According to research of C6H and C (n = 0, ±2, ±4, ±6), C6H (n = 0–6), we sustained that their σ and π orbit were different and the locations of electrons were difficult to confirm in ionic structures. Thus, neither 4n + 2 rule nor NICS values can precisely estimate the aromaticity of ionic structures. Besides, through WBI (NBO) research of C6H6‐A and C6‐A (A = Be, B, N, O, Mg, Al, Si, S, and Fe) structures, we found that C6H6 was easy to accept electrons, contrarily, C6 was prone to bestowing electrons. Moreover, C6H6 took the symmetrical carbon atoms form feeble interaction or bond, and C6 used all carbon atoms to impact with other atom. C6H6 generated two contrapuntal single bonds with oxygen, sulfur, and nitrogen atoms, whereas C6 molecule formed double bond with oxygen and nitrogen atoms, two conjoint single bonds with sulfur atom. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 相似文献
13.
Andrea Decker Falk Simon Kamal Boubekeur Dieter Fenske Patrick Batail 《无机化学与普通化学杂志》2000,626(1):309-313
Reactions of dry THF/MeCN solutions of Ca[Re6SCl(Cla)6] with silylated derivatives E(SiMe3)2 (E = PhAs, PSiMe3, HN, O, S) and addition of trialkylphosphine PPr3 afford in high yields and at room temperature either the neutral clusters [Re6SX(PPr3)] ( 1 : X = As, 2 : X = P) or the ionic compounds [Re6SX(PPr3)]2+ · [Re6S6Cl8]2– ( 3 : X = NH, 4 : X = O, 5 : X = S). The compounds 1 – 5 were characterised by X‐ray crystal structure analysis. A di‐substitution reaction occurs on the {Re6SCl}4+ cluster core, where the two inner μ3‐chloro ligands Cli are substituted by X (X = As, P, NH, O, S) and all six terminal chloro ligands Cla are exchanged by terminal PPr3‐ligands. 相似文献
14.
A New Mixed Valence Strontium Niobium Oxide Sr7Nb24+Nb45+O21 \documentclass{article}\pagestyle{empty}\begin{document}$ \widehat = $\end{document} Sr1.167NbO3.5 The unknown compound Sr7Nb6O21 kristallisiert nach Einkristall-Röntgenbeugungsdaten rhomboedrisch (Raumgruppe C? R3 ; a = 16,450(5) Å, α = 19,85(1)° trigonale Aufstellung: a = 5,670(1), c = 48,364(13) Å). The compound is built up by perovskite blocks with a width of 6 octahedra. The crystal chemistry especially of the interspace between those blocks is discussed in respect to related compounds. 相似文献
15.
T. Bartik B. Happ Anke Sieker Sylvia Stein Angela Sorken K.-H. Thiele Christian Kriebel Gyula Plyi 《无机化学与普通化学杂志》1992,608(2):173-183
Bimetallic and trimetallic compounds containing unsupported bonds of subgroup 4 metals (M = Ti, Zr, Hf) and Co were prepared by hydride elimination (A) from RM derivatives (R1 = PhCH2; RN; R2 = Me, Et)) and by salt elimination (B) from RMX (X = Cl, Br; R.1 = PhCH2, RN and R3O; R3= i-Pr, n-Bu)) by reaction with HCo(CO)4 and Na[Co(CO)4], respectively. Compounds RMCo(CO)4 with R1 = PhCH2, RM[Co(CO)4]2 R.1 = PhCH2, were prepared both by methods A and B, while (R3O)4-n Ti[Co(Co)4]n (n = 1, 2) compounds were obtained by reaction B. Several tertiary phosphine and phosphite derivatives of the former two types were obtained by substitution of a carbonyl group by PR ligand or by A type reaction of HCo(CO)3(PR with RM compounds. 相似文献
16.
Synthesis, Vibrational Spectra, and Crystal Structure of ( n ‐Bu4N)2[(W6Cl )F ] · 2 CH2Cl2 and 19F NMR Spectroscopic Evidence of the Mixed Cluster Anions [(W6Cl )F Cl ]2–, n = 1–6 The reaction of (n‐Bu4N)2[(W6Cl)Cl] with CF3COOH in dichloromethane gives intermediately a mixture of the cluster anions [(W6Cl)(CF3COO)Cl]2–, n = 1–6. By treatment with NH4F the outer sphere coordinated trifluoracetato ligands are easily substituted and the components of the series [(W6Cl)FCl], n = 1–6 are formed and characterized by their distinct 19F NMR chemical shifts. An X‐ray structure determination has been performed on a single crystal of (n‐Bu4N)2[(W6Cl)F] · 2 CH2Cl2 (orthorhombic, space group Pbca, a = 15.628(4), b = 17.656(3), c = 20.687(4) Å, Z = 4). The low temperatur IR (60 K) and Raman (20 K) spectra are assigned by normal coordinate analysis based on the molecular parameters of the X‐ray determination. The valence force constants are fd(WW) = 1.89, fd(WF) = 2.43 and fd(WCl) = 0.93 mdyn/Å. 相似文献
17.
Synthesis, Crystal Structures, and Vibrational Spectra of [OsBr(acac)(PPh3)] and [OsBr(acac)(AsPh3)] By reaction of tetrabromoacetylacetonatoosmate(IV) with PPh3 or AsPh3 in ethanol the complexes [OsBr(acac)(PPh3)] ( 1 ) and [OsBr(acac)(AsPh3)] ( 2 ) are formed, which are purified by chromatography on silica gel. X-ray structure determinations of single crystals of ( 1 ) (monoclinic, space group P 21/n, a = 13.035(2), b = 18.2640(14), c = 16.636(3) Å, β = 112.776(14)°, Z = 4) and ( 2 ) (monoclinic, space group P 21/c, a = 13.23(5), b = 18.35(2), c = 16.65(2) Å, β = 112.9(5)°, Z = 4) result in mean bond distances Os–P = 2.413, Os–As = 2.483, Os–Br = 2.488 and Os–O = 2.037 Å. The vibrational spectra (10 K) exhibit the inner ligand vibrations of the acac, PPh3 and AsPh3 groups with nearly constant frequencies and the stretching vibrations of OsP at 499–522, of OsAs at 330–339, of OsBr at 213–214 and of OsO in the range 460–694 cm–1. 相似文献
18.
Synthesis, Crystal Structures, and Vibrational Spectra of [(Ph3P)2N]2[(W6Cl )I ] · 2 Et2O · 2 CH2Cl2 and [(Ph3P)2N]2[(W6Cl )(NCS) ] · 2 CH2Cl2 By treatment of [(W6Cl)I]2– with (SCN)2 in dichloromethane at –20 °C the hexaisothiocyanato cluster anion [(W6Cl)(NCS)]2– is formed. X‐ray structure determinations have been performed on single crystals of [(Ph3P)2N]2[(W6Cl)I] · 2 CH2Cl2 · 2 Et2O ( 1 ) (triclinic, space group P1, a = 10.324(5), b = 14.908(3), c = 17.734(8) Å, α = 112.78(2)°, β = 99.13(3)°, γ = 92.02(3)°, Z = 1) and [(Ph3P)2N]2[(W6Cl)(NCS)] · 2 CH2Cl2 ( 2 ) (triclinic, space group P1, a = 11.115(2), b = 14.839(2), c = 17.036(3) Å, α = 104.46(1)°, β = 105.75(2)°, γ = 110.59(1)°, Z = 1). The thiocyanate ligands of 2 are bound exclusively via N atoms with W–N bond lengths of 2.091–2.107 Å, W–N–C angles of 173.1–176.9° and N–C–S angles of 178.1–179.3°. The vibrational spectra exhibit characteristic innerligand vibrations at 2067–2045 (νCN), 879–867 (νCS) and 490–482 (δNCS). Based on the molekular parameters of the X‐ray determination of 1 the vibrational spectra of the corresponding (n‐Bu4N) salt of 1 are assigned by normal coordinate analysis. The valence force constants are fd(WW) = 1.61, fd(WI) = 1.23 and fd(WCl) = 1.10 mdyn/Å. 相似文献
19.
Zur Verbindungsbildung von MeO:M2O3. VI. Darstellung und Strukturaufklärung von Sr1,33 Pb0,67 Al6O11
Compound Formation MeO: M2O3. VI. Synthesis and Structure Determination of Sr1,33 Pb0,67 Al6O11 Single crystal of Sr1,33Pb0.67Al6O11 could be prepared with a PbO flux. (Space group D–Pnnm, a = 22.13, b = 4.88, c = 8.42 Å, Z = 4) Sr2+ and Pb2+ are statistically intercalated into a framework of AlO6 octahedra and AlO4 tetrahedra. The typical coordination of Sr2+ and Pb2+ is realized by occupying different positions in the same cavern. 相似文献
20.
63Cu-NMR.-Spectra of Cu(CH3CN)4X (X = ClO, BF, PF) and Cu(C5H5N)4X (X = ClO, BF) in solution are reported at different temperatures and concentrations. The influence of temperature on the linewidth and chemical shift indicates an equilibrium of Cu(CH3CN) and Cu(C5H5N) with another complex of lower symmetry. The preferential solvation of Cu (I) by pyridin in a mixture acetonitrile/pyridine is clearly shown. 相似文献