Crystal structures of rubidium scandium bis(hydrogenphosphate), RbSc(HPO4)2, and ammonium scandium bis(hydrogenphosphate), NH4Sc(HPO4)2 (original) (raw)
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Journal of Coordination Chemistry, 2008
Six complexes, rubidium and cesium 3,5-dinitropyrid-2-onate (2DNPO), 3,5-dinitropyrid-4onate (4NDPO), 3,5-dinitropyrid-4-one-N-hydroxylate (4DNPNO), were synthesized and characterized by elemental analysis, FT-IR, TG-DTG and X-ray single-crystal diffraction analysis. All the complexes crystallized from water and one of them was a hydrate. Rubidium 3,5-dinitropyrid-4-one-N-hydroxylate was crystallized with the 1 : 2 stoichiometry as Rb[H(4DNPNO) 2 ] upon absorption of carbon dioxide. The structural determinations showed that the coordination sphere around a metal centre is made up of oxygen atoms and nitrogen atoms, except for the 4DNPNO complexes, where the coordination sphere accommodates exclusively oxygen atoms. The coordination numbers of the metal centers vary from 8, 10, 11 to 12, while the ligands, each employing its pyridone tautomer, link with metal cations. Bridging oxygen atoms play an important role in construction of two-and/or three-dimensional networks of these complexes. Hydrogen bonding contributes to the connectivity within a given sheet in Rb[H(4DNPNO) 2 ]; aromaticstacking interactions exist only in Cs(4DNPNO). The interactions between metal atoms and ligands are generally very weak. The organization of all layer structures appears to be governed mainly by steric effects and electrostatic forces with very little directional influence of the cations. The thermogravimetric analyses of these complexes showed the following consecutive processes: loss of NO 2 groups, collapse of the pyridyl ring backbones and finally inorganic residue formation. These complexes could be used as probes in template effects of heavy alkali-metal cations in the organization of biorelevant ligands and as environment-friendly energetic catalysts in solid propellants.
Zeitschrift für anorganische und allgemeine Chemie, 2001
Rb(H 2 NC 10 H 6 SO 3 )´H 2 O crystallizes in space group P2 1 with two formula units in the asymmetric unit, the crystal being twinned by a 180°rotation about [1 0 0]. The structure was determined from X-ray diffraction data, and refined, based on two twin components, to yield a final R value of 0.0557 for 2754 reflections. The structure consists of alternating layers of aminonaphthalenesulfonate and rubidium ions. There are two distinct rubidium environments, the metal ions linked by the sulfonate groups and bridging water molecules into an infinite sheet. The sulfonate groups are bidentate, monodentate and bridging, all oxygen atoms being bound to at least one metal. The amino groups do not participate in coordination to the metal. Aromatic moieties from neighboring hydrophilic metallo-layers interleave to form the hydrophobic layers. There is some similarity to the analogous sodium and potassium structures, however the rubidium compound is distinguished by an infinite cationic layer, rather than columns observed for the other two structures.
Acta Crystallographica Section E Crystallographic Communications
The crystal structure of sodium rubidium hydrogen citrate, NaRbHC6H5O7 or [NaRb(C6H6O7)] n , has been solved and refined using laboratory powder X-ray diffraction data, and optimized using density functional techniques. This compound is isostructural to NaKHC6H5O7. The Na atom is six-coordinate, with a bond-valence sum of 1.16. The Rb atom is eight-coordinate, with a bond-valence sum of 1.17. The distorted [NaO6] octahedra share edges to form chains along the a-axis direction. The irregular [RbO8] coordination polyhedra share edges with the [NaO6] octahedra on either side of the chain, and share corners with other Rb atoms, resulting in triple chains along the a-axis direction. The most prominent feature of the structure is the chain along [111] of very short, very strong hydrogen bonds; the O...O distances are 2.426 and 2.398 Å. The Mulliken overlap populations in these hydrogen bonds are 0.140 and 0.143 electrons, which correspond to hydrogen-bond energies of about 20.3 kcal mol−1...
The preparation and characterisation of rubidium dodecamolybdophosphate, Rb3(MoO3)12PO4·4H2O
Journal of Molecular Structure, 1990
The preparation of rubidium dodecamolybdophosphate, Rbs (Moos) 12P04*4H20, is reported for the first time and is characterised using vibrational spectroscopy. X-ray diffraction confirms the cubic structure (Keggin) and Td crystal symmetry. The infrared and Raman spectra indicate that an 11-molybdophosphate species is present, formed by elimination of MOO, from the dodecamolybdophosphate ions, and supports earlier suggestions in the literature of a 12-to ll-molybdophosphate equilibrium.
Journal of Solid State Chemistry, 2005
Four scandium phosphate-based structures have been prepared hydrothermally in the presence of the primary diamines ethylenediamine and diaminobutane and the primary amine cyclohexylamine and characterised by single crystal and powder X-ray diffraction, 31 P and 45 Sc solid-state MAS NMR and chemical analysis. Charge balancing protons in the structures are located using bond valence sum calculations and postulated hydrogen bonding networks. Compound 1, [(H 3 NC 2 H 4 NH 3 ) 3 ][Sc 3 (OH) 2 (PO 4 ) 2 (HPO 4 ) 3 (H 2 PO 4 )], P1, a ¼ 5:4334ð6Þ, b ¼ 8:5731ð9Þ, c ¼ 16:3022ð18Þ ( A, a ¼ 79:732ð4Þ, b ¼ 83:544ð4Þ, g ¼ 80:891ð5Þ1, Z ¼ 2, is built up of scandium phosphate ribbons, based on trimers of ScO 6 octahedra linked by OH groups. These trimers are joined through phosphate groups bound through three oxygens, and are decorated by phosphate groups linked by a single oxygen atom. The ribbons are arranged parallel to the a-axis and linked one to another by fully protonated ethylenediammonium ions. Compounds 2, [(H 3 NC 4 H 8 NH 3 ) 3 ][(Sc(OH 2 )) 6 Sc 2 (HPO 4 ) 12 (PO 4 ) 2 ], P3, a ¼ 13:8724ð3Þ, c ¼ 9:4351ð11Þ ( A, Z ¼ 1, and 3, [(H 3 NC 4 H 8 NH 3 ) 2 (H 3 O)][Sc 5 F 4 (HPO 4 ) 8 ], C2=m, a ¼ 12:8538ð4Þ, b ¼ 14:9106ð4Þ, c ¼ 10:1906ð3Þ ( A, b ¼ 101:17ð9Þ1, Z ¼ 2, were prepared using diaminobutane as the organic template in the absence and presence, respectively, of fluoride ions in the gel. Compound 2 has a pillared layered structure, in which ScO 6 octahedra are linked by three vertices of hydrogenphosphate groups into sheets and the sheets pillared by ScO 6 octahedra to give a three-dimensionally connected framework isostructural with a previously reported iron(III) hydrogenphosphate. The protonated diaminobutane molecules occupy cavities between the layers. Compound 3 has a layered structure in which isolated ScO 6 octahedra and tetrameric arrangements of ScO 4 F 2 octahedra, the latter linked in squares through fluoride ions, are connected by phosphate tetrahedra that share two or three oxygens with scandium atoms. In this structure, the protonated diaminobutane molecules connect the layers, the -NH 3 + groups fitting into recesses in the layers. Compound 4, [(C 6 H 11 NH 3 )][ScF(HPO 4 )(H 2 PO 4 )], Pbca, a ¼ 7:650ð3Þ, b ¼ 12:867ð5Þ, c ¼ 26:339ð11Þ ( A, Z ¼ 8, the first scandium phosphate to be prepared with a monoamine, is also a layered solid. In this case, the layers contain single chains of ScO 4 F 2 octahedra which share fluoride ions in trans positions. Phosphate tetrahedra bridge across scandiums via two of their four oxygens, both within the same chain and also to neighbouring chains to make up the layer. The protonated amine groups of the cyclohexylamine molecules achieve close contact with phosphates of the layer, while the cyclohexyl moieties, which are in the chair configuration, project into the interlayer space. r 2005 Elsevier Inc. All rights reserved.
Solid State Sciences, 2000
Ammonium and barium cyclotriphosphate monohydrate, BaNH 4 P 3 O 9 ·1H 2 O, was prepared for the first time by using Boullé's process [1] by Durif et al. who reported a complete description of the atomic arrangement. BaNH 4 P 3 O 9 ·1H 2 O is monoclinic P2 1 /n with the following unit-cell dimensions: a=11.70(1)Å, b=12.12(1)Å, c=7.559(5)Å, β=101.05(5) and Z=4. Therefore, some discrepancies appear in the literature and stimulated further investigation of this compound to conclude concerning hydration level and structure. The thermal behavior of BaNH 4 P 3 O 9 ·nH 2 O showed that this cyclotriphosphate is a dihydrate and up to now no other hydrate has been described for this salt. So, the present study reports the chemical preparation, thermal behavior and crystal structure of BaNH 4 P 3 O 9 ·2H 2 O, the first cyclotriphosphate of mixed ammonium-bivalent cations M II with a new general formula M II NH 4 P 3 O 9 ·nH 2 O. Dehydration and decomposition of such cyclotriphosphates lead generally to long-chain polyphosphates, [M II (PO 3 ) 2 ] ∞ which can be used as corrosion inhibitors . The title compound has been studied through the following techniques: X-ray diffraction, IR spectrometry and thermal analyses TGA-DTA coupled. sablanca, Maroc. b Groupe des Matériaux Inorganiques, IPCMS, UMR 7504, 23 rue du Loess, 67037 Strasbourg Cedex, France. Thermal behavior and infrared studies of NiRb 4 (. Synthesis, thermal behavior and crystal structure of SrRbP 3 O 9 ·3H
K 2 SO 4 Type Isomorphs: Prediction of Structures and Refinement of Rb 2 CrO 4
Acta Crystallographica Section B-structural Science, 1998
The crystal structures of members within a group of isostructural compounds may be successfully predicted. This is demonstrated for the fl-K2SO 4 group isomorphs with the general formula M2XO4, which were chosen as a family of very closely related compounds nearly all with accurately refined crystal structures. The unit-cell parameters and the fractional atomic coordinates are shown to exhibit systematic variations with both cation and anion size, as well as the Mulliken charge on the O atom in the tetrahedral anion. This allows the prediction of the crystal structures of members in the series, with only the chemical composition of the compound being known. The agreement is good, except for an early structure determination of Rb2CrO4. The now refined structure gives excellent agreement with that predicted.