The effect of solvents (toluene, dichloromethane, and hexane) was studied on the polymerization of propylene with the octahedral complexes bis(trimethylsilyl) benzamidinate titanium dichloride(a), bis(acetylacetonate) titanium dichloride(b), and bis(diethylamino) titanium di-2-(diphenylphosphanylamino)pyridine as catalytic precursors and methylalumoxane as the cocatalyst. For comparison, the polymerization was also performed in plain liquid propylene without the addition of any solvent. The obtained polymers were fractionated by refluxing hexane. The activity of the complexes and the molecular weights and tacticities of the whole polymers and their different fractions were the studied parameters. (c) 2005 Wiley Periodicals, Inc.