420132-16-7Relevant academic research and scientific papers
Iron phosphinimide and phosphinimine complexes: Catalyst precursors for ethylene polymerization
LePichon, Luc,Stephan, Douglas W.,Gao, Xiaoliang,Wang, Qinyan
, p. 1362 - 1366 (2002)
Reaction of Li[NPt-Bu3] with FeCl2 affords [Cl3Fe2(μ-NPt-Bu3)2] 1 in 71% yield. This mixed valent Fe(III)-Fe(II) undergoes reversibly one-electron oxidation to generate [Cl3Fe2(μ-NPt-Bu3)2]+. Chemical oxidation with [Cp2Fe]PF6 yields [Cl2Fe(μ-NPt-Bu3)]2 2. The reaction of Li[NPt-Bu3] with FeBr3 affords [Br4Fe2(μ-NPt-Bu3)2] 3, while the reaction of FeCl3 with Me3-SiNPCy3 gives [Cl2Fe(μ-NPCy3)]2 4. Hydrolysis of 3 yields the species [(t-Bu3PNH)Br2Fe]2-(μ-O) 5. These species have also been evaluated as catalysts for the polymerization of ethylene and copolymerization of ethylene/octene. These species were found to be single-site catalysts even under rather demanding conditions (50-160 °C, 100-300 psig ethylene), although the activities are generally low. Compound 5 affords polymer similar to that produced by 3, suggesting that MAO dehydrates 5 generating a catalyst similar to that derived from 3. Compounds 1, 2, 4, and 5 have been crystallographically characterized.
