Zirconium and hafnium tert-butoxides and tert-butoxo-beta-diketonate complexes - Isolation, structural characterization and application in the one-step synthesis of 3D metal oxide nanostructures

Abstract

Long term storage of the pure commercial Zr((OBu)-Bu-t)(4) in a sealed ampoule results in crystallization of a new high symmetry phase of Zr3O((OBu)-Bu-t)(10) (1). Modification of Zr((OBu)-Bu-t)(4) and Hf((OBu)-Bu-t)(4) with 2,2,6,6,-tetramethy1-3,5-heptanedione (Hthd) produces dependent on the stoichiometry two types of derivatives, M((OBu)-Bu-t)(2)(thd)(2) (2, 3) and M(OtBu)(thd)(3) (4, 5) M = Zr(2, 4), Hf(3, 5), which have all been characterized by NMR and mass-spectral studies and for 4 and 5 also by complete X-ray single crystal studies. The latter failed for 2 and 3 in the view of their poor X-ray reflectivity. Addition of minor amounts of n-C5H11OH to 3 resulted in isolation of an unusual heteroleptic complex Hf-2(OH)((OC5H11)-C-n)((OBu)-Bu-t)(2)(thd)(4) (6). Thermal decomposition of compounds 1 and 3 in nitrogen atmosphere was studied for different thermal regimes by TGA-FTIR approach, revealing in all cases the formation of tetragonal ZrO2 and monoclinic HfO2 respectively, along with iso-butene, butanol and water for 1 and the same mixture including also Hthd for 3. Decomposition of 3 occurred always through intermediate melting, while higher heating rate for 1 permitted to achieve decomposition on in situ evaporation resulting in 3D hedgehog nanostructures according to SEM. (C) 2013 Elsevier Ltd. All rights reserved.

Keywords

Metal alkoxides; beta-Diketonate complexes; ZrO2; HfO2; Metal-organic decomposition (MOD)

Published in

Polyhedron
2013, volume: 53, pages: 150-156
Publisher: PERGAMON-ELSEVIER SCIENCE LTD

SLU Authors

• Spijksma, Gerald I.

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    
  • University of Twente

• Seisenbaeva, Gulaim

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

• Kessler, Vadim

  • Department of Molecular Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Materials Chemistry
Inorganic Chemistry

Publication identifier

• DOI: https://doi.org/10.1016/j.poly.2013.01.046

Permanent link to this page (URI)

https://res.slu.se/id/publ/55995