Abstract
Polymerizations of 1-decene (DC), 1-dodecene (DD), and 1-tetradecene (TD) by Cp*TiMe(2)(O-2,6-(i)Pr(2)C(6)H(3)) (1)-[Ph(3)C][B(C(6)F(5))(4)] (borate) catalyst have been explored in the presence of Al cocatalyst. The polymerizations of DC and DD, in n-hexane containing a mixture of Al(i)Bu(3) and Al(n-C(8)H(17))(3), proceeded with high catalytic activities in a quasi-living manner, affording high molecular weight polymers (activity 4120-5860 kg-poly(DC)/mol-Ti·h, M(n) for poly(DC) = 7.04-7.82 × 10(5), after 20 min at -30 °C). The PDI (M(w)/M(n)) values in the resultant polymers decreased upon increasing the ratio of Al(n-C(8)H(17))(3)/Al(i)Bu(3) with decreasing the activities at -30 °C. The PDI values also became low when these polymerizations were conducted at low temperatures (-40 or -50 °C); high molecular weight poly(DD) with low PDI (M(n) = 5.26 × 10(5), M(w)/M(n) = 1.16) was obtained at -50 °C. The TD polymerization using 1-borate-Al(i)Bu(3) catalyst (conducted in n-hexane at -30 °C) afforded ultrahigh molecular weight poly(TD) (M(n) = 1.02 × 10(6), M(w)/M(n) = 1.38), and the PDI values also decreased with increasing the Al(n-C(8)H(17))(3)/Al(i)Bu(3) ratio.