Copolymerizations of Ethylene with 1-Hexene over ansa-Metallocene Diamide Complexes

摘要

We have performed Copolymerizations of ethylene with 1-hexene using various ansa-metallocene compounds in the presence of the non-coordinative [CPh_3][B(C_6F_5)_4] ion pair as a cocatalyst.The metallocenes chosen for this study are isospecific metallocene diamide compounds,rac-(EBI)Zr(NMe_2)_2 [1,EBI = ethylene-1,2-bis(l-indenyl)],rac-(EBI)Hf(NMe_2)_2 (2),rac-(EBI)Zr(NC_4H_8)_2 (3),and rac-(CH_3)_2Si(l-C_5H_2-2-CH_3-4-/C_4H_9)_2 Zr(NMe_2)_2 (4),and syndiospecific metallocene dimethyl compounds,ethylidene(cyclopentadienyl)(9-fluorenyl) ZrMe_2 [5,Et(Flu)(Cp)ZrMe_2] and isopropylidene(cyclopentadienyl)(9-fluorenyl)ZrMe2 [6,/Pr(Flu)(Cp)ZrMe_2].The copolymerization rate decreased in the order 4>1~3>2>5>6.The reactivity of 1-hexene decreased in the order 2>6>1~3~5>4.We characterized the microstructure of the resulting poly(ethylene-co-1-hexene) by ~I3C NMR spectroscopy and investigated various other properties of the copolymers in detail.