The synthesis and olefin polymerization behavior of a new TADDOL-based Ti(IV) complex, (4R,5R)-2,2-dimethyl-alpha,alpha,alpha ',alpha '-tetrakis[bis-(3,5-trifluoromethyl)phenyl]-1,3-dioxolane-4,5-dimethanolato-titanium(IV) dichloride, are described. Upon activation with MAO, this complex polymerized ethylene, producing ultra-high molecular weight linear polyethylene (UHMWPE) with activities up to 4500 kg mol (Ti)(-1) [C2H4](-1) h(-1) atm(-1) and molecular weights up to 3.25 x 10(6). The optimal temperature for UHMWPE synthesis was 50 degrees C. This complex is also capable of copolymerizing ethylene with 1-hexene and 1-octene, giving high molecular weight copolymers with alpha-olefin incorporation up to 7.8%. The copolymers, obtained with a different ratio of comonomers, are statistical, according to the analysis of the C-13 NMR spectra. The reaction parameters that influenced the copolymerization behavior, such as comonomer concentration, reaction temperature and [Al]/[Ti] molar ratio, are examined in detail. Furthermore, high catalytic activities up to 12,531 kg mol(Ti)(-1) [C2H4](-1) h(-1) atm(-1) were observed in copolymerization of ethylene and 1-hexene or 1-octene with the 2/MAO catalytic system. The obtained copolymers possess high molecular weights (M-w = 1.4 x 10(6)-ethylene/1-hexene and 1.86 x 10(6)-ethylene/1-octene) with broad MWD (M-w/M-n = 3.04-8.23) and high comonomer incorporation degrees (up to 6.2 mol% of 1-hexene and 7.8 mol% of 1-octene). Depending on the synthesis conditions, it is possible to form both a statistical copolymer and a block copolymer.