Tuning Metal Stoichiometry in Heterometal Alkoxides: First Structurally Characterised Molecular Precursor to BaZrO3
✍ Scribed by Michael Veith; Sanjay Mathur; Volker Huch; Timo Decker
- Book ID
- 101278896
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 417 KB
- Volume
- 1998
- Category
- Article
- ISSN
- 1434-1948
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✦ Synopsis
Barium / Zirconium / O ligand / Heterometal alkoxides Manipulable metal ratios are accessible in a series of distribution of terminal ligands at each of the metal centers.
One of the barium atoms possesses one -OtBu and one heterometal Ba-Zr alkoxides by changing the size and the charge of the ligands. The synthesis and characterisation of tBuOH as terminal ligands, while the terminal ligands on the second barium atom are two THF molecules; the zirconium four mixed-metal Ba-Zr species [BaZr 2 (OtBu)
center bears -OtBu groups as the terminal ligands. Hydrolysis of compound 3 with one equivalent of water, and [BaZr(OH)(OiPr) 5 (iPrOH) 3 ] 2 (4), based on different Ba/Zr stoichiometries, are reported. The molecular structures of 1, followed by alcoholysis (iPrOH) of the resulting product, gave 4. The structure of 4 shows a planar tetrametallic Ba 2 Zr 2 2, and 4 have been determined by single-crystal X-ray diffraction studies. 1 exhibits a bow-tie structural motif in frame capped by two µ 3 -hydroxo ligands. The coordination figure of the zirconium atoms resembles a distorted which a trigonally distorted six-coordinate barium atom is chelated by two bipyramidal {Zr(OtBu) 5 } -units. 2 reveals a octahedron, whereas the geometry of the barium centers is best described as capped trigonal prisms. Both 3 and 4 are triangular "Ba 2 Zr(µ 3 -OtBu) 2 (µ 2 -OtBu) 3 " core structure formed by the fusion of three octahedra built about two Ba excellent precursors to morphologically pure BaZrO 3 ceramic by the sol-gel process. atoms and a Zr atom. The structure is unique in terms of the