Alkaline Earth Metal Zirconate Perovskites MZrO sub(3) (M=Ba super(2+), Sr super(2+), Ca super(2+)) Derived from Molecular Precursors and Doped with Eu super(3+) Ions

The effect of alkaline earth metal alkoxides on the protonation of zirconocene dichloride was investigated. This approach enabled the design of compounds with preset molecular structures for generating high-purity binary metal oxide perovskites MZrO sub(3) (M=Ba super(2+), Sr super(2+), Ca super(2+)). Single-source molecular precursors [Ba sub(4)Zr sub(2)( mu sub(6)-O)( mu sub(3), eta super(2)-OR) sub(8)(OR) sub(2 )( eta super(2)-HOR) sub(2)(HOR) sub(2)Cl sub(4)], [Sr sub(4)Zr sub(2)( mu sub(6)-O)( mu sub(3), eta super(2)-OR) sub(8)(OR) sub(2 )(HOR) sub(4)Cl sub(4)] , [Ca sub(4)Zr sub(2)( mu sub(6)-O)( mu sub(3), eta super(2)-OR) sub(8)(OR) sub(2 )Cl sub(4)], and [Ca sub(6)Zr sub(2)( mu sub(2), eta super(2)-OR) sub(12)( mu -Cl) sub(2)( eta super(2)-HOR) sub(4)l sub(6)]8CH sub(2)Cl sub(2) were prepared via elimination of the cyclopentadienyl ring from Cp sub(2)ZrCl sub(2) as CpH in the presence of M(OR) sub(2) and alcohol ROH (ROH=CH sub(3)OCH sub(2)CH sub(2)OH) as a source of protons. The resulting complexes were characterized by elemental analysis, IR and NMR spectroscopy, and single-crystal X-ray diffraction. The compounds were then thermally decomposed to MCl sub(2)/MZrO sub(3) mixtures. Leaching of MCl sub(2) from the raw powder with deionized water produced highly pure perovskite-like oxide particles of 40-80nm in size. Luminescence studies on Eu super(3+)-doped MZrO sub(3) revealed that the perovskites are attractive host lattices for potential applications in display technology. Molecular perovskite precursors: A simple, high-yield synthetic route for the preparation of single-source molecular precursors for preparing alkaline earth metal zirconate perovskites MZrO sub(3) (M=Ba, Sr, and Ca; see figure), which were subsequently doped with Eu super(3+) ions, is presented. The CaZrO sub(3):Eu super(3+) phosphor showed the highest luminescent intensity and is a highly promising candidate for applications in trichromatic white LEDs.