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Lhoste, J., Galven, C., Leblanc, M., Maisonneuve, V., Rocquefelte, X., Jobic, S. & Bujoli-Doeuff, M. (2013) Crystal structure and optical properties of new 0D-hybrid hydroxyfluorotitanates. Solid State Sci. 24 101–106.
Added by: Laurent Cournède (2016-03-10 21:23:29) |
| Type de référence: Article DOI: 10.1016/j.solidstatesciences.2013.07.014 Numéro d'identification (ISBN etc.): 1293-2558 Clé BibTeX: Lhoste2013 Voir tous les détails bibliographiques  |
Catégories: MIOPS Mots-clés: Amine, crystal structure, Density functional theory, dihydrate, fluoride, germanium, h2o, hydrate, Microwave, optical properties, Organic-inorganic hybrid, tif4, tin, Titanate, titanium Créateurs: Bujoli-Doeuff, Galven, Jobic, Leblanc, Lhoste, Maisonneuve, Rocquefelte Collection: Solid State Sci. |
Consultations : 1/581
Indice de consultation : 4% Indice de popularité : 1% |
| Résumé |
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New 0D hybrid organic-inorganic hydroxyfluorotitanates result from the microwave assisted reactions in autoclaves of TiF4 with organic amines (3-5 diamino-1,2,4,triazol (guaz), ethylenediamine (en) and diethylenetriamine (dien)) and concentrated aqueous HF in ethanol at 190 degrees C for 1 h. Four compounds, [Hguaz](2)center dot(TiF4.9(OH)(1.1)) (I), [H(2)guaz]center dot(TiF4.3(OH)(1.2)) (II), [H(2)en]center dot(TiF4.3(OH)(1.7)) (III) and [H(2)dien]- center dot(Ti(F,OH)(6))center dot 2H(2)O (IV) are prepared and characterized. All structures are built up from isolated (Ti(F,OH)(6))(2-) anions interacting with mono- or di-protonated amines which local symmetry dictates the long range stacking of the Ti(F,OH)(6) octahedra. Insertion of crystallized water molecules is only observed for IV. The experimental optical gaps of I, II and III have been measured at about 3.4 eV and compare well with the theoretical values estimated from the examination of density of state diagrams. The optical thresholds are mainly due to O(2p) -{>} Ti(3d) electronic transitions, the F(2p) -{>} Ti(3d) charge transfers occurring at higher energy. (c) 2013 Elsevier Masson SAS. All rights reserved.
Added by: Laurent Cournède |