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U.r.k. Rao - One of the best experts on this subject based on the ideXlab platform.
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Mode of thermal decomposition of diammonium lithium oxyfluoro vanadate (DALOFV) and diammonium Rubidium oxyfluoro vanadate (DAROFV)
Thermochimica Acta, 1995Co-Authors: S.j. Patwe, U.r.k. RaoAbstract:Abstract Diammonium lithium and diammonium Rubidium oxyfluoro vanadates have been synthesised by solid state reactions at room temperature and their thermal decomposition mechanism determined by using simultaneous TG/DTA. The reaction intermediates have been synthesised separately and the residues identified by XRD to confirm the decomposition mechanism. In the case of the lithium Compound, removal of two NH 4 F molecules takes place in three steps, whereas in the case of the Rubidium Compound this takes place in two steps.
Kurt O. Klepp - One of the best experts on this subject based on the ideXlab platform.
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Two New Quaternary Thiophosphates with Pseudo One‐dimensional Structures: Syntheses and Crystal Structures of Cs3Sm[PS4]2 and Rb3Sm[PS4]2
Zeitschrift für anorganische und allgemeine Chemie, 2008Co-Authors: Susanne Milot, Christian Näther, Wolfgang Bensch, Kurt O. KleppAbstract:The new thiophosphates Rb3Sm[PS4]2 and Cs3Sm[PS4]2 were obtained as pale yellow needles using an in-situ formed thiophosphate flux. Rb3Sm[PS4]2 crystallizes in the space group P21 with a = 9.7061(19) A, b = 6.7517(14) A, c = 11.395(2) A, β = 90.63(3)°, (Z = 2); Cs3Sm[PS4]2 in space group P21/n with a = 15.311(3) A, b = 6.8762(14) A, c = 15.352(3) A, β = 99.49(3)°, (Z = 4). The crystal structures are characterized by the formation of complex anionic chains, which run along the [010] direction in both structures. One of the two independent thiophosphate groups connects three Sm3+ cations to form an infinite zigzag like arrangement, while the other acts as a terminal ligand to one Sm3+ions. Such a μ3 or face-grafting coordination mode of a [PS4]3− anion is not very common. The Sm3+ ions are in bicapped trigonal prismatic chalcogen coordination. The average Sm–S distances within the trigonal prisms are close to 2.88A, while the bonds to the capping atoms are distinctly longer. The chains are chiral yet their symmetry is close to 21/m. In contrast to the Rubidium Compound, Cs3Sm[PS4]2 contains both enantiomorphs. In both structures the chains are arranged as a distorted hexagonal rod packing.
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The crystal structures of CsAu3S2, RbAu3Se2 and CsAu3Se2 and their relationship to the CsCu3S2 structure type
Journal of Alloys and Compounds, 1996Co-Authors: Kurt O. Klepp, C. WeithalerAbstract:Abstract The new Compounds CsAu 3 S 2 , RbAu 3 Se 2 and CsAu 3 Se 2 were prepared by high temperature reactions. They are isostructural and crystallize in P3m1 , Z = 1 and a = 6.192(1) A. c =5.080(2) A for CsAu 3 S 2 , α =6.112(4) a, c =5.224(6) A for RbAu 3 Se 2 and a = 6.281(1) A, c =5.205(1) A for CsAu 3 Se 2 . Their crystal structures were determined by single crystal diffractometer data. They are characterized by the formation of corrugated chalcogenoaurate layers 2 -[Au, O 2 ], separated by the alkali cations. Au is in a strictly linear coordination ( d (AuS) 2.32(1) A, d (AuSe) 2.450(7) A and 2.434(4) A respectively), the bond angles of the chalcogens are close to 80%. The shortest AuAu distances (3.056(2) A) occur in the Rubidium Compound. The crystal structures are related to the CsCu 3 S 2 type.
Mineo Sato - One of the best experts on this subject based on the ideXlab platform.
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Synthesis and structure determination of new layered perovskite Compound, KLaTa2O7
Journal of Alloys and Compounds, 1997Co-Authors: Kenji Toda, Tomonobu Honma, Mineo SatoAbstract:Abstract A new layered perovskite Compound, KLaTa 2 O 7 , was synthesized by ion-exchange reaction from the Rubidium Compound, RbLaTa 2 O 7 . The crystal structure of KLaTa 2 O 7 was determined by Rietveld analysis from powder X-ray diffraction patterns. It is analogous to the structure of the corresponding niobate Compound. This layered perovskite Compound is a new member of the Dion-Jacobson series with n =2 for the general formula A[M n −1 B n O3 n +1 ] (A=monovalent cations, B=Nb or Ta). The structural features of KLaTa 2 O 7 are discussed by comparison with other Compounds of the ALaTa 2 O 7 family and the titanate Compounds.
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Structural Characterization and Ion Conductivity of MCa2NaNb4O13 (M=Rb, Na) with Four Units of Perovskite Layer
Journal of the Ceramic Society of Japan, 1993Co-Authors: Mineo Sato, Yasuhisa Kono, Tetsuro JinAbstract:Layered perovskite, RbCa2NaNb4O13, with four units of perovskite layer was synthesized by solid state reaction. A sodium ion-exchanged Compound, NaCa2NaNb4O13⋅1.7H2O, was also synthesized by ion-exchange reaction of a Rubidium Compound with NaNO3 molten salt. The anhydrous sodium ion-exchanged Compound was stable in the temperature range from 350 to 600°C in an ambient atmosphere. The crystal structures of the three materials were determined using the Rietveld method by powder XRD data. The most reliable solutions were obtained for the structural model assuming that the site for a large cation within the perovskite layer, corresponding to the A site for an ideal perovskite, is occupied by the mixed species with the atomic ratio of Ca:Na=2/3:1/3. The structures of these Compounds are substantially the same as those of MLaNb2O7 (M=Rb, Na) except for the thickness of the perovskite layer. A fairly high ion conductivity attributed to the interlayer cation was observed at high temperatures for the sodium Compound.
S.j. Patwe - One of the best experts on this subject based on the ideXlab platform.
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Mode of thermal decomposition of diammonium lithium oxyfluoro vanadate (DALOFV) and diammonium Rubidium oxyfluoro vanadate (DAROFV)
Thermochimica Acta, 1995Co-Authors: S.j. Patwe, U.r.k. RaoAbstract:Abstract Diammonium lithium and diammonium Rubidium oxyfluoro vanadates have been synthesised by solid state reactions at room temperature and their thermal decomposition mechanism determined by using simultaneous TG/DTA. The reaction intermediates have been synthesised separately and the residues identified by XRD to confirm the decomposition mechanism. In the case of the lithium Compound, removal of two NH 4 F molecules takes place in three steps, whereas in the case of the Rubidium Compound this takes place in two steps.
Arnold Adam - One of the best experts on this subject based on the ideXlab platform.
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Komplexe Alkalimetall-carbonat-hydrogencarbonate mit fünffach koordiniertem Zink: NaA2{Zn2[H(CO3)2](CO3)2(H2O)2} mit A = K, Rb / Complex Alkalimetal-carbonates-hydrogencarbonates with Penta-Coordinated Zinc: NaA2{Zn2[H(CO3)2](CO3)2(H2O)2] with A = K,
Zeitschrift für Naturforschung B, 1995Co-Authors: Yue Qing Zheng, Arnold AdamAbstract:The new alkalimetal-hydrogenbis(carbonato)-bis(carbonato)complexes with penta-coordinated zinc atoms, NaA2{Zn2[H(CO3)2](CO3)2(H2O)2} with A = Kor Rb, crystallize in the monoclinic system, P21/n (no. 14), Z = 2 with a = 1057,9(1), b = 1102,2(1), c = 514,9(1) pm, β = 92,94(1)°, VEZ = 599,6(2) · 106 pm3, R = 0,052, Rw = 0,029 for the potassium Compound and with a = 1068,2(2), b = 1131,6(4), c = 518,6(1) pm, β = 92,07(1)°, VEZ = 626,4(4)·106 pm3, R = 0,050, Rw = 0,028 for the Rubidium Compound. These Compounds are the first to be structurally characterized with a simultaneous presence of discrete [H(CO3)2]3-and CO32- anions. The crystal structure of the isostructural Compounds contains two-dimensional infinite {Zn2[H(CO3)2](CO3)2(H2O)2} layers parallel [1 0 1] with zinc coordinated in a slightly distorted trigonal-bipyramidal geometry. The layers are held together by hydrogen bonds from water molecules to oxygen atoms of the carbonato groups in adjacent layers. Potassium or Rubidium atoms are located between the layers, and sodium atoms in smaller vacancies within the layers. The hydrogen bond of the [H(CO3)2]3- anion is very short, O···O: 247,4(2) pm (K) and 246,9(5) pm (Rb). The carbonate groups in both Compounds exhibit significant deviations from D3h symmetry in accordance with the vibrational modes observed in the IR spectra. The thermal behaviour of the potassium Compound is also reported.
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Die ersten Hydrogencarbonate mit einer trimeren [H2(CO3)3]4−‐Baugruppe: Zur Darstellung und Kristallstruktur von Rb4H2(CO3)3 · H2O und K4H2(CO3)3 · 1,5 H2O
Zeitschrift f�r anorganische und allgemeine Chemie, 1995Co-Authors: Vytas Cirpus, Arnold AdamAbstract:Rb4H2(CO3)3 · H2O und K4H2(CO3)3 · 1,5 H2O wurden durch die Umsetzung von (CH3)2CO3 mit RbOH bzw. KOH in wasserhaltigem Methanol dargestellt. In der Kristallstruktur von Rb4H2(CO3)3 · H2O (orthorhombisch, Pnma (Nr. 62), a = 1 218,0(1) pm, b = 1 572,3(6) pm, c = 615,9(1) pm, VEZ = 1 179,5(5) · 106 pm3, Z = 4, R1 (I ≥ 2σ(I)) = 0,027, wR2(I ≥ 2σ(I)) = 0,055) liegen trimere [H2(CO3)3]4−-Anionen vor. K4H2(CO3)3 · 1,5 H2O kristallisiert in einer OD-Struktur. Die ermittelte Superpositionsstruktur (orthorhombisch, Pbam (Nr. 55), a = 1 161,8(1) pm, b = 597,0(1) pm, c = 383,85(3) pm, VEZ = 266,25(6) · 106 pm3, Z = 1, R1(I ≥ 2σ(I)) = 0,035, wR2(I ≥ 2σ(I)) = 0,074) kann von der Struktur der Rubidiumverbindung abgeleitet werden. Die thermische Zersetzung der Substanzen wird diskutiert. The First Hydrogencarbonates with a Trimeric [H2(CO3)3]4− Group: Preparation and Crystal Structure of Rb4H2(CO3)3 · H2O and K4H2(CO3)3 · 1.5 H2O Rb4H2(CO3)3 · H2O and K4H2(CO3)3 · 1,5 H2O were prepared by means of the reaction of (CH3)2CO3 with RbOH resp. KOH in aqueous methanole. Trimer [H2(CO3)3]4−-anions were found in the crystal structure of Rb4H2(CO3)3 · H2O (orthorhombic, Pnma (no. 62), a = 1 218.0(1) pm, b = 1 572.3(6) pm, c = 615.9(1) pm, VEZ = 1 179.5(5) · 106 pm3, Z = 4, R1(I ≥ 2σ(I)) = 0.027, wR2(I ≥ 2σ(I)) = 0.055). K4H2(CO3)3 · 1,5 H2O crystallizes in an OD-structure. The determined superposition structure (orthorhombic, Pbam (no. 55), a = 1 161.8(1) pm, b = 597.0(1) pm, c = 383.85(3) pm, VEZ = 266.3(1) · 106 pm3, Z = 1, R1(I ≥ 2σ(I)) = 0.035, wR2(I ≥ 2σ(I)) = 0.074) can be derived from the structure of the Rubidium Compound. The thermal decomposition of the substances is discussed.
