Crystallographic new light on an old complex: NaMg[Cr(oxalato) 3]·9H 2O and structure redetermination of the isomorphous aluminum(III) compound
The crystal structure of sodium and magnesium tris(oxalato)chromato(III) nona hydrate, NaMg[Cr(C2O4)3]·9H2O, has been determined by X-ray diffraction methods. It crystallizes in the trigonal P3c1 space group with (in the hexagonal setting) a = b = 16.9635(4), c = 12.5247(3) Å, and Z = 6 molecules pe...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2015 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/53996 |
| Acceso en línea: | http://hdl.handle.net/11336/53996 |
| Access Level: | acceso abierto |
| Palabra clave: | Crystal Structures Na/Mg Salts Tris(Oxalato)Aluminato(Iii) Tris(Oxalato)Chromato(Iii) Vibrational Spectra https://purl.org/becyt/ford/1.3 https://purl.org/becyt/ford/1 https://purl.org/becyt/ford/1.4 |
| Sumario: | The crystal structure of sodium and magnesium tris(oxalato)chromato(III) nona hydrate, NaMg[Cr(C2O4)3]·9H2O, has been determined by X-ray diffraction methods. It crystallizes in the trigonal P3c1 space group with (in the hexagonal setting) a = b = 16.9635(4), c = 12.5247(3) Å, and Z = 6 molecules per unit cell. The Cr(III) and sodium ions are in octahedral environments coordinated to three oxalate molecules and arranged in a honeycomb-like layered structure perpendicular to the crystal c-axis. There are three different octahedral [Mg(H2O)6]2+ hydrated ions that fill the honeycomb holes giving rise to electrically neutral Na[Mg(H2O)6][Cr(oxalato)3] crystal slabs. Neighboring slabs are bridged by the remaining three water molecules through H-bonds and therefore the whole crystal can be more properly described as Na[Mg(H2O)6][Cr(oxalato)3]·3H2O. Also, the structure of isomorphous NaMg[Al(C2O4)3]·9H2O compound has been re-examined and compared with the chromium(III) complex. Infrared and Raman spectra of both complexes were also recorded and briefly discussed. |
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