From molecules to materials: some examples in yttrium and lanthanide chemistry

Liliane G Hubert-Pfalzgraf (1) , S. Daniele (1)

1 IRC - Institut de recherches sur la catalyse

Hydrolytic and hydrothermal transformations were applied to yttrium alkoxides, namely Y5O(OiPr)13, Y3(OtBu)9(tBuOH)2 and [Y8O6(OtBu)12]m. The resulting powders were characterized by XRD, TGA and transmission electron microscopy (TEM). Hydrolysis of the octanuclear oxo species gave nanocrystalline (5–6 nm) cubic Y2O3 at 400 °C by annealing of an oxohydroxide. Hydrothermal transformation in basic media (200 °C, 10 h, 17 atm) of Y5O(OiPr)13 gave amorphous Y2O3 as well as crystalline platelets and nanowires of Y(OH)3. Transformation into cubic yttria was achieved at 300 °C. The lability of the M–OR bond allows easy formation of mixed-metal species, giving access to doped materials of high homogeneity and crystallinity, as shown by a Y2O3 matrix doped by Pr2O3. Modification of Y5O(OiPr)13 by polymerisable ligands provided molecular oxohydroxide aggregates that can be used for access to organic-inorganic materials by copolymerisation reactions.

Mots clés: Lanthanides; Nanomaterials; Alkoxides; Multimetallic oxides; Polymerisable ligands; Organic–inorganic materials; Sol–gel

Domaines: Catalyse

Liliane G Hubert-Pfalzgraf, S. Daniele. From molecules to materials: some examples in yttrium and lanthanide chemistry. Comptes Rendus. Chimie, 2004, 7, pp.521-527. ⟨10.1016/j.crci.2004.03.001⟩. ⟨hal-00007403⟩