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