Local environment and composition of magnesium gallium layered double hydroxides determined from solid-state 1H and 71Ga NMR spectroscopy
| Autor: | Vadim Zorin, Ulla Gro Nielsen, Andrew S. Lipton, Line Boisen Petersen |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
Chemistry
Magnesium Inorganic chemistry Layered double hydroxides chemistry.chemical_element Nuclear magnetic resonance spectroscopy engineering.material Condensed Matter Physics Electronic Optical and Magnetic Materials Inorganic Chemistry NMR spectra database Crystallography Solid-state nuclear magnetic resonance Elemental analysis Materials Chemistry Ceramics and Composites engineering Molecule Physical and Theoretical Chemistry Gallium |
| Zdroj: | Boisen Staal, L, Lipton, A S, Zorin, V & Nielsen, U G 2014, ' Local environment and composition of magnesium gallium layered double hydroxides determined from solid-state 1 H and 71 Ga NMR spectroscopy ', Journal of Solid State Chemistry, vol. 219, pp. 242-246 . https://doi.org/10.1016/j.jssc.2014.07.023 |
| ISSN: | 0022-4596 |
| DOI: | 10.1016/j.jssc.2014.07.023 |
| Popis: | Ordering of gallium(III) in a series of magnesium gallium (MgGa) layered double hydroxides (LDH’s), [Mg1-xGax(OH)2(NO3)x yH2O] was investigated using solid-state 1H and 71Ga NMR spectroscopy as well as powder X-ray diffraction. Three different proton environments from Mg3-OH, Mg2Ga-OH and intergallery water molecules were assigned and quantified using {1H,71Ga} HETCOR and 1H MAS NMR. A single 71Ga site originating from the unique Ga site in the MgGa LDH’s was observed in 71Ga MAS and 3QMAS NMR spectra. Both 1H MAS NMR spectra recorded at 21.1 T (900MHz) and elemental analysis show that the synthesized MgGa LDH’s had a lower Mg:Ga ratio than that of the starting reactant solution. The origin of this is the formation of soluble [Ga(OH)4]- complexes formed during synthesis, and not due to formation of insoluble gallium (oxy)hydroxides. No sign of Ga-O-Ga connectivities or defects were detected for the MgGa LDH’s. Ordering of gallium(III) in a series of magnesium gallium (MgGa) layered double hydroxides (LDHs), [Mg1−xGax(OH)2(NO3)x·yH2O] was investigated using solid-state 1H and 71Ga NMR spectroscopy as well as powder X-ray diffraction. Three different proton environments from Mg3single bondOH, Mg2Gasingle bondOH and intergallery water molecules were assigned and quantified using {1H,71Ga} HETCOR and 1H MAS NMR. A single 71Ga site originating from the unique Ga site in the MgGa LDH׳s was observed in 71Ga MAS and 3QMAS NMR spectra. Both 1H MAS NMR spectra recorded at 21.1 T (900 MHz) and elemental analysis show that the synthesized MgGa LDH׳s had a lower Mg:Ga ratio than that of the starting reactant solution. The origin of this is the formation of soluble [Ga(OH)4]− complexes formed during synthesis, and not due to formation of insoluble gallium (oxy)hydroxides. No sign of Gasingle bondOsingle bondGa connectivities or defects were detected for the MgGa LDH׳s. |
| Databáze: | OpenAIRE |
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