Nickel Complexes Bearing New <i>P,N</i>-Phosphinopyridine Ligands for the Catalytic Oligomerization of Ethylene
作者:Fredy Speiser、Pierre Braunstein、Lucien Saussine
DOI:10.1021/om034203i
日期:2004.5.1
[NiCl2(P,N)] complexes 9−12. These Ni(II) complexes are paramagnetic in solution, as determined by the Evans method. Whereas they were inactive for the oligomerization of ethylene in the presence of methylalumoxane (MAO), they provided activities up to 61 000 mol of C2H4/((mol of Ni) h) (11) in the presence of only 6 equiv of AlEtCl2. The selectivities for C4 olefins were as high as 92% (12 with 2
新的膦基吡啶配体2-[((二苯基膦基)甲基] -6-苯基吡啶(5),2-(2,6-二甲基苯基)-6-[[(二苯基膦基)甲基]吡啶(6),2-(2,6-为了比较它们的立体电子性质对催化性能的影响,已经制备了二异丙基苯基)-6-[((二苯基膦烷基)甲基]吡啶(7)和2- [2-(二苯基膦基苯基)苯基] -6-甲基吡啶(8)。它们各自的单核的行为[的NiCl 2(P,N)]配合物9 - 12。这些Ni(II)络合物在溶液中是顺磁性的,这是通过Evans方法确定的。尽管在甲基铝氧烷(MAO)存在下它们对乙烯的低聚反应无活性,但在仅存在6当量浓度的情况下,它们提供的活性高达61 000 mol C 2 H 4 /(((Ni mol)h)(11)的AlEtCl 2。C 4烯烃的选择性高达92%(12与2当量的AlEtCl 2)。