Imino-Indolate Half-Titanocene Chlorides: Synthesis and Their Ethylene (Co-)Polymerization

A series of imino-indolate half-titanocene chlorides, Cp'Ti(L)Cl-2 (C1-C7: Cp' = C5H5, MeC5H4, C5Me5, L = imino-indolate ligand), were synthesized by the reaction of Cp'TiCl3 with sodium imino-indolates. All complexes were characterized by elemental analysis, H-1 and C-13 NMR spectroscopy. Moreover, the molecular structures of two representative complexes C4 and C6 were confirmed by single crystal X-ray diffraction analysis. On activation with methylaluminoxane (MAO), these complexes showed good catalytic activities for ethylene polymerization (up to 7.68 x 10(6) g/mol(Ti).h) and ethylene/1-hexene copolymerization (up to 8.32 x 10(6) g/mol(Ti).h), producing polyolefins with high molecular weights (for polyethylene up to 1808 kg/mol, and for poly(ethylen-co-1-hexene) up to 3290 kg/mol). Half-titanocenes containing ligands with alkyl substituents showed higher catalytic activities, whereas the half-titanocenes bearing methyl substituents on the cyclopentadienyl groups showed lower productivities, but produced polymers with higher molecular weights. Moreover, the copolymerization of ethylene and methyl 10-undecenoate was demonstrated using the C1/MAO catalytic system. The functionalized polyolefins obtained contained about 1 mol % of methyl 10-undecenoate units and were fully characterized by several techniques such as FT=1R, H-1 NMR, C-13 NMR, DSC, TGA and GPC analyses. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polyrn Chera 47: 357-372, 2009