Molecular assemblies based on the template-directing effect of anionic polyoxometalate clusters and organic cationic flexibility

详细信息    查看全文

• 作者：Zhangang Han ; Tao Chai ; Yanna Wang ; Yuanzhe Gao ; Changwen Hu
• 关键词：Polyoxometalate ; Inclusion compound ; Thermalstability ; Flexible organo-cation ; Template effect
• 刊名：Polyhedron
• 出版年：2010
• 出版时间：13 January 2010
• 年：2010
• 卷：29
• 期：1
• 页码：196-203
• 全文大小：1136 K

文摘

Molecular assembly processes by utilizing the template-directing effect of anionic polyoxometalate clusters and the flexible organic cation have achieved three hybrids: (H₂bpp)(Hbpp)[PMo₁₂O₄₀]·3DMF (1), (H₂bpp)(Hbpp)(bpp)₂ [PMo₉V₃O₄₀(VO)₂]₂ (2), and (H₂bpp)₂[β-Mo₈O₂₆] (3) (bpp = 1,3-bis(4-pyridyl)propane). Three compounds were characterized using single crystal X-ray crystallography, elemental analysis, IR, XPS, EPR, voltammetric behavior and TGA. Crystal structural analyses revealed that compounds 1–3 were all constructed from protonated organic bpp cations with different POM clusters: isolated α-Keggin P–Mo cluster in 1; dimer of bi-capped α-Keggin P–Mo–V anions linked through a {V₂O₂} unit in 2; β-octamolybdate isopolyanion in 3, respectively. All three assemblies demonstrated a higher thermal stability. The protonated bpp cations lost at temperature higher than 300 °C that the strong intermolecular interactions may account for the high initial temperature of weight loss. The electrochemistry property of compound 2 modified carbon paste electrode was also studied in 1 M H₂SO₄ aqueous.