Nickel and iron complexes with oxazoline- or pyridine-phosphonite ligands; synthesis, structure and application for the catalytic oligomerisation of ethylene
作者:Fredy Speiser、Pierre Braunstein、Lucien Saussine
DOI:10.1039/b401792g
日期:——
phosphonite group underlines the importance of the ligand on the catalytic properties of its metal complex. An unprecedented dinuclear iron complex [FeCl2(4,4-dimethyl-2-[(1-hydroxy-1-methyl)ethyl]-4,5-dihydrooxazolate)]2 20 was also obtained which contains two pentacoordinated metal centers coordinated by a bridging-chelating oxazoline-alcoholate. Complexes 18-20 are paramagnetic in solution, as determined
双(恶唑啉基)苯基亚膦酸酯配体(双(4,4-二甲基-2-(1-羟基-1-甲基乙基)-4,5-二氢恶唑)苯基膦酸酯,NOPONMe2))和新的吡啶-亚膦酸酯配体(2-乙基(1'-甲基-1-羟基)吡啶-6H-二苯并[c,e] [1,2]草酰磷已用于制备单核络合物[NiCl2(NOPONMe2)] 18和[NiCl2(6 )2] 19,分别以高达57300 mol C2H4 mol Ni(-1)h(-1)的活性催化乙烯的低聚反应(19在仅存在6当量的AlEtCl2的情况下)。C4二聚体的选择性高达90%(在只有2当量AlEtCl2的情况下为18),而1-丁烯的选择性为C4馏分的21-22%。在400或800当量的MAO作为助催化剂的情况下,复杂19产生周转频率分别为7400摩尔C2H4摩尔Ni(-1)h(-1)和13200摩尔C2H4摩尔Ni(-1)h(-1)。1-丁烯和乙烯二聚体的选择性类似于