Synthesis and characterization of mixed-metal aryloxo-organometallic precursors for oxide-ceramic materials

Potential single-source molecular precursors [Ba{(mu-ddbfo)(2)MRx}(2)] (ddbfoH = 2,3-dihydro-2,2-dimethylbenzofuran-7-ol; M/R/x = Al/Me/2, Al/Et/2, Ga/Me/2, or Zn/Et/1) for mixed metal oxide materials were prepared by the reaction of barium aryloxide [Ba(ddbfo)(2)(ddbfoH)(2)]center dot 3ddbfoH with an appropriate organometallic compound in toluene. The precursors were characterized by elemental analysis, IR and NMR spectroscopy, and single-crystal X-ray structural analysis. The Ba/Al-2 and Ba/Ga-2 complexes undergo thermal decomposition to give mixed metal oxides BaM2O4 (M = Al, at 1300 degrees C for both Me and Et derivatives; Ga, at 1430 degrees C. Instead, the Ba/Zn-2 complex decomposes to a mixture of BaCO3 and different metal oxides. The chemical composition and surface morphology of heterobimetallic oxides were analyzed by SEM-EDS and X-ray powder diffraction (XRD) that revealed the formation of highly pure oxide materials with micrometer particle sizes.