Details for 1-hexene polymerization by Cp*TiMe2(O-2,6-(Pr2C6H3)-Pr-i) (1) have been explored in the presence of organoboron and organoaluminum compounds. The polymerization took place in a living manner with remarkably high catalyst efficiency at -30degreesC, when both Ph3CB(C6F5)(4) and (AlBu3)-Bu-i were used as cocatalysts under the optimized conditions. The resultant poly(I-hexene) possessed high molecular weight with narrow molecular weight distribution (M-n = 186.5 x 10(4), M-w/M-n = 1.27). Effects of polymerization temperature and monomer concentration were explored, and the M. values increased linearly upon the consumption of 1-hexene in all cases. Use of a mixture of Al(n-C8H17)(3) and (AlBu3)-Bu-i was also found to be effective, but relatively excess amount of (AlBu3)-Bu-i was necessary in order for this catalytic reaction to proceed efficiently. (C) 2003 Elsevier B.V. All rights reserved.