Darstellung und Eigenschaften von Heteropolykationenverbindungen, IV: Darstellung und Struktur von Natriumdodekaaluminogalliumsulfat-Ikosihydrat, Na[GaO4Al12(OH)24(H2O)12](SO4)4 ·xH2O mitx∼20

Görz, H.; Schönherr, Siegfried; Pertlik, F.

doi:10.1007/bf00815915

Cited by 11 publications

(8 citation statements)

References 8 publications

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“…Emphasis was placed on verifying if the geometrical considerations can justify the higher thermal stability of GaAl 12 , as suggested by others. , The main crystallographic data are reported in Table , selected geometrical data in Table . To facilitate the comparison with previously published crystallographic data of the cubic selenate salt of Al 13 27 and of the cubic sulfate salt of GaAl 12 , we have maintained the same atom-labeling scheme.…”

Section: Resultsmentioning

confidence: 99%

“…The main crystallographic data are provided in Table . The structural model adopted for the refinement of the structures of Al 13 and GaAl 12 sulfate salts is that reported by Goerz et al . Refinements were performed anisotropically for all the non-H atoms (48 parameters) with the SHELX-76 computer program …”

Section: Methodsmentioning

confidence: 99%

“…Usually there is no distinction between which type of Al substitution occurs (tetrahedral or octahedral). In our view, convincing physical evidence for MAl 12 hybrids has been reported only in the case of Ga 3+ . − The reports of V 3+ ions, Fe 3+ , − Re 3+ ions, La 3+ , and the transition M in general are based on chemical rather than structural analyses. Workers generally characterize the PILCs rather than the pillars.…”

Section: Introductionmentioning

confidence: 91%

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Metal Substitution in Keggin-Type Tridecameric Aluminum−Oxo−Hydroxy Clusters

1997

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The species resulting from a typical preparation for metal-substituted hybrids of the Keggin tridecamer, Al or [AlOAl(OH)(OH)], were examined by performing Al NMR on the solutions during aging and by studying the precipitated sulfate salts via solid stateAl NMR and powder X-ray diffraction (XRD). Aqueous mixtures (0.25 mol L) of AlCl and another metal ion (M), in a 12:1 mole ratio (Al:M), where M = Fe, Zn, Ga, In, Sn, La, and Bi, were subjected to forced hydrolysis by addition of NaOH (1.0 mol L) until OH/(Al + M) = 2.25, and the kinetics of Al formation and disappearance with aging at 80 °C was monitored by Al NMR spectroscopy. Al units polymerize on aging with an apparent rate constant (k) of 4.8(8) × 10 h to form a species referred to as AlP. Only the solutions containing Ga and Sn exhibited faster Al conversion rates. GaAl forms quickly at 80 °C (k = 0.54 h) and is more stable than AlP. Sn apparently promotes AlP formation (k = 0.38 h). XRD and solid state NMR reveal that only the Ga hybrid can be prepared by this method. No hybrid formation was evidenced using M = Mg, Fe, Co, Ni, Cu, Zn, In, La, or Ce at 25 °C or M = Co or La under reflux conditions. Isostructural (cubic symmetry) single crystals were obtained for the sulfate salts of Al and GaAl. Single-crystal XRD analysis of these two polyoxocations provides the first rigorous comparison between them and shows they have very similar structures. The main crystallographic data for Al and GaAl are as follows: Na[AlOAl(OH)(HO)](SO)·10HO, cubic, F4̄3m, a = 17.856(2) Å, Z = 4; Na[GaOAl(OH)(HO)](SO)·10HO, cubic, F4̄3m, a = 17.869(3) Å, Z = 4. Thus, the greater thermal stability of GaAl cannot be rationalized in terms of the overall geometric considerations, as suggested by others. Solid state NMR also shows the coordination symmetries of the outer 12 Al nuclei in both clusters to be similar.

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 91%

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Metal Substitution in Keggin-Type Tridecameric Aluminum−Oxo−Hydroxy Clusters

1997

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“…Two decades after Johanssen's work on the ε -Al 13 , considerable progress was made by the research teams at the University of Freiburg in Germany and Calgary in Canada who independently published a series of papers that examined metal substitutions and polymerization. − Single-atom substituents include Ge(IV) (yielding GeO 4 Al 12 (OH) 24 (H 2 O) 12 8+ in solution = GeAl 12 , refs and ] and Ga(III) (GaO 4 Al 12 (OH) 24 (H 2 O) 12 7+ = GaAl 12 , refs −51). Crystals of Na[GaO 4 Al 12 (OH) 24 (H 2 O) 12 (SeO 4 ) 4 ]· x (H 2 O), [GeO 4 Al 12 (OH) 24 (H 2 O) 12 (SeO 4 ) 4 ]· x (H 2 O), and Na[AlO 4 Al 12 (OH) 24 (H 2 O) 12 (SeO 4 ) 4 ]· x (H 2 O) can be grown at 80−90 °C by hydrolysis of the appropriate AlCl 3 + MCl 3 solutions followed by filtration, dilution, cooling, and addition of selenate to induce crystallization.…”

Section: 12 Heteroatom ε-Mal12 Structuresmentioning

confidence: 99%

Large Aqueous Aluminum Hydroxide Molecules

2005

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“…These oligomers fall into two broad structural classes. Most familiar are molecules that consist of a central tetrahedral MO 4 unit that is surrounded by 12 edge-sharing AlO 6 moieties arranged in a structure similar to the ε-isomer of the Baker−Figgis Keggin structures. − Crystals can be grown at 80−90 °C by hydrolysis of the appropriate solutions followed by crystallization with sulfate or selenate. − The salts can be back-extracted into an aqueous solution in the presence of aqueous BaCl 2 to release the ions MO 4 Al 12 (OH) 24 (H 2 O) 12 7+/8+ (aq) [M = Al(III), Ga(III), and Ge(IV)]. − A larger molecule has also been synthesized recently − and naturally forms from aging of a solution containing AlO 4 Al 12 (OH) 24 (H 2 O) 12 7+ . The ion stoichiometry is Al 2 O 8 Al 28 (OH) 56 (H 2 O) 26 18+ (aq), and the ion somewhat resembles a dimer of two δ-isomers of the Baker−Figgis Keggin structures.…”

mentioning

confidence: 99%