Molecular Heterobimetallic Approach to Li-Containing MgO Nanoparticles with Variable Li-Concentrations Using Lithium-Methylmagnesium Alkoxide Clusters

Heitz S., Epping J., AKSU Y., Driess M.

CHEMISTRY OF MATERIALS, cilt.22, sa.16, ss.4563-4571, 2010 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 22 Sayı: 16
  • Basım Tarihi: 2010
  • Doi Numarası: 10.1021/cm100415m
  • Dergi Adı: CHEMISTRY OF MATERIALS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.4563-4571
  • Akdeniz Üniversitesi Adresli: Hayır

Özet

Facile synthesis and characterization of the first heterobimetallic lithium-methylmagnesium-alkoxide clusters [Li(thf)(MeMg)(3)(mu(3)-OR)(4)] (R = Pr-i (1a), 'Bu (1b), (Cy)Hex (1c)) having a cubane-shaped LiMg3O4 core is reported. They have been employed as molecular single-source precursors for "bottom up" synthesis of Li-containing MgO nanoparticles with varying Li-concentrations. This can be achieved by solid state decomposition of homogeneous mixtures of the latter compounds (1a-c) with the corresponding homometallic alkylmagnesium alkoxide cubanes [MeMg(mu(3)-OR))(4) (R = Pr-i (2a), 'Bu (2b), (Cy)Hex (2c)). Characterization of the final obtained materials was accomplished by a combination of different analytical techniques such as TGA, PXRD, TEM, Raman spectroscopy, Li-7 MAS NM R spectroscopy, elemental analysis, and nitrogen adsorption. The different parameters that affect the composition and morphology of the Li-containing MgO nanoparticles have been examined. It has been found that Li concentrations up to 1 wt % lead to well-defined crystalline materials, where the Li ions are likely incorporated in the magnesium oxide lattice, whereas higher Li concentrations afford less-ordered materials, which consist of additional crystalline and amorphous phases.
Abstract Image

Facile synthesis and characterization of the first heterobimetallic lithium-methylmagnesium-alkoxide clusters [Li(thf)(MeMg)3(μ3-OR)4] (R = iPr (1a), tBu (1b), CyHex (1c)) having a cubane-shaped LiMg3O4 core is reported. They have been employed as molecular single-source precursors for “bottom up” synthesis of Li-containing MgO nanoparticles with varying Li-concentrations. This can be achieved by solid state decomposition of homogeneous mixtures of the latter compounds (1a−c) with the corresponding homometallic alkylmagnesium alkoxide cubanes [MeMg(μ3-OR)]4 (R = iPr (2a), tBu (2b), CyHex (2c)). Characterization of the final obtained materials was accomplished by a combination of different analytical techniques such as TGA, PXRD, TEM, Raman spectroscopy, 7Li MAS NMR spectroscopy, elemental analysis, and nitrogen adsorption. The different parameters that affect the composition and morphology of the Li-containing MgO nanoparticles have been examined. It has been found that Li concentrations up to 1 wt % lead to well-defined crystalline materials, where the Li ions are likely incorporated in the magnesium oxide lattice, whereas higher Li concentrations afford less-ordered materials, which consist of additional crystalline and amorphous phases.