544694-41-9Relevant academic research and scientific papers
Boron trifluoride activation of ethylene oligomerization and polymerization catalysts
Komon, Zachary J.A.,Bazan, Guillermo C.,Fang, Cindy,Bu, Xianhui
, p. 95 - 102 (2003)
Addition of BF3·Et2O to {[(C6H5)2PC6H4(μ- CO2)-κ3P,O,O′]Ni(η1-CH 2C6H5)}2 gives [(C6H5)2PC6H4C(O-BF 3)O-κ2P,O]Ni(η3-CH2C 6H5) (4). The single crystal structure of 4 is consistent with substantial positive charge at the nickel atom. Addition of ethylene to solutions of 4 in toluene provides ethylene oligomers. The average molecular weight of the products is larger than that of the oligomers obtained using [(C6H5)2PC6H4C(OB(C 6F5)3)O-κ2P,O]Ni(η 3-CH2C6H5) (1). When 2 equiv. of Et2O·BF3 are added to {(H3C)C[N(2,6-(CHMe2)2-C6H 3)]C(O)[N(2,6-(CHMe2)2-C6H 3)]-κ2N,O}Ni(η1-CH2C 6H5)(PMe3) (5) one obtains {(H3C)C[N(2,6-(CHMe2)2-C6H 3)]C[O-BF3][N(2,6-(CHMe2)2-C 6H3)]-κ2N,N′}Ni(η 3-CH2C6H5) (7). Two isomers of 7 are observed by NMR spectroscopy and are incorporated into the crystal lattice, as shown by X-ray diffraction studies. Polyethylene is obtained upon exposure of a solution of 7 to ethylene. Active species can also be generated in situ by addition of BF3 gas, Et2O·BF3 or tBuMeO·BF3 to 5.
