Details

Autor(en) / Beteiligte

• Bai, Guangcai
• Singh, Sanjay
• Roesky, Herbert W
• Noltemeyer, Mathias
• Schmidt, Hans-Georg

Titel

Mononuclear Aluminum Hydroxide for the Design of Well-Defined Homogeneous Catalysts

Ist Teil von

• Journal of the American Chemical Society, 2005-03, Vol.127 (10), p.3449-3455

Ort / Verlag

Washington, DC: American Chemical Society

Erscheinungsjahr

2005

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• An unprecedented aluminum hydroxide LAlMe(OH) (5; L = HC[(CMe)(2,6-iPr2C6H3N)]2) has been prepared by the hydrolysis of LAlMeCl (4). For the preparation of 5, the reagents of KOH, water, and KH, as well as the two-phase ammonia/toluene system, were used. Further reactions of 5 with Cp2ZrMe2 (8) and Cp2ZrHCl in toluene lead to the intermolecular elimination of CH4 and H2 and the formation of μ-O-bridged dinuclear aluminum and zirconium complexes [LAlMe(μ-O)ZrMeCp2] (6) and [LAlMe(μ-O)ZrClCp2] (7), respectively, in high yields. The crystal structure reveals that 5 is a monomer with terminal OH and Me groups. The X-ray structure analysis shows that 6 and 7 contain a bent Al−(μ-O)−Zr core with terminal Al−Me and Zr−Me or Zr−Cl arrangements. The methylalumoxane (MAO)-activated compounds 6 and 7 exhibit high catalytic activity for the polymerization of ethylene. Under comparable polymerization conditions, the MAO/6 and MAO/7 catalyst systems show considerably higher activity and much lower MAO:catalyst ratios than that of MAO/8.