Dichlorocobalt(II) Complexes Ligated by Bidentate 8-(Benzoimidazol-2-yl)quinolines: Synthesis, Characterization, and Catalytic Behavior toward Ethylene
作者:Tianpengfei Xiao、Peng Hao、Gerald Kehr、Xiang Hao、Gerhard Erker、Wen-Hua Sun
DOI:10.1021/om2003392
日期:2011.9.26
A series of (8-(benzoimidazol-2-yl)quinoline)dichlorocobalt(II) complexes was prepared and characterized, and single-crystal X-ray diffraction revealed the distorted-tetrahedral geometry around the cobalt atom. Activated with methylaluminoxane (MAO), these cobaltous complexes showed special properties of ethylene reactivity: ethylene oligomerization with an observed activity up to 3 x 10(4) g (mol of Co)(-1) h(-1) atm(-1) with reaction temperature lower than 60 degrees C at ambient or 10 atm ethylene pressure and ethylene polymerization with an observed activity up to 1 x 10(5) g (mol of Co)(-1) h(-1) atm(-1) with reaction temperature higher than 60 degrees C at 30 atm ethylene pressure, indicating two potentially active species formed at different reaction parameters. The obtained polyethylenes with high molecular weights and narrow molecular weight distributions, to the best of our knowledge, give the first proof of dichlorocobalt complex precatalysts bearing bidentate ligands acting as single-site catalysts in ethylene polymerization.
作者:Tianpengfei Xiao、Shu Zhang、Gerald Kehr、Xiang Hao、Gerhard Erker、Wen-Hua Sun
DOI:10.1021/om200338b
日期:2011.7.11
The series of N-benzimidazolyl-substituted 2-alkyl-8-(benzimidazol-2-yl)quinolines (L1–L10) and 2-phenyl-8-(benzimidazol-2-yl)quinolines (L11–L14) and their respective bidentate iron(II) dichloride complexes (C1–C14) were synthesized and fully characterized. The molecular structures of a representative ligand (L5) and iron complexes (C2, C7) were determined by X-ray crystal structure analyses, and