New Bulky Phosphino−Pyridine Ligands. Palladium and Nickel Complexes for the Catalytic Polymerization and Oligomerization of Ethylene
作者:Hsin-Pei Chen、Yi-Hung Liu、Shie-Ming Peng、Shiuh-Tzung Liu
DOI:10.1021/om030242i
日期:2003.11.1
geometry around the metal center is square planar for the Pd(II) complexes and tetrahedral for the Ni(II) complexes. The cationic methylpalladium(II) complexes showed poor activity in the catalytic polymerization of ethylene, but the nickel complexes were highly active with the activation of MAO. The nickel complexes catalyzed the polymerization of ethylene with an Al/Ni ratio of 150, whereas di- and trimerization
两个大体积膦基吡啶配体(6-三甲苯基-2 - ((二芳基膦)甲基)吡啶,P〜Ñ)成功通过用6-溴-2-甲基吡啶mesitylboronic酸的铃木偶合的方法制备,接着phosphinylation。这些配体在分别用(COD)PdMeCl和(DME)NiBr 2处理后容易形成钯和镍配合物。这些P〜Ñ通过光谱数据和X射线晶体学表征螯合的Pd(II)和Ni(II)配合物。金属中心周围的配位几何形状对于Pd(II)配合物为正方形平面,对于Ni(II)配合物为四面体。阳离子甲基钯(II)配合物在乙烯的催化聚合反应中显示出较差的活性,但是镍配合物随着MAO的活化具有很高的活性。镍络合物以Al / Ni比为150催化乙烯的聚合,而当Al / Ni比为500时观察到二聚和三聚。获得的聚乙烯是高度结晶的。