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Copolymerizations of ethylene and 1-dodecene were conducted with a series of ansa-fluorenylamidodimethyltitanium complexes, [ t-BuNSiMeFlu]TiMe ( 1a), [ t-BuNSiMe(2,7-BuFlu)]TiMe ( 1b), and [(1-adamantyl)NSiMe(2,7-BuFlu)]TiMe ( 1c) activated by modified methylaluminoxane. The activity increased by the introduction of the alkyl groups on the fluorenyl and amido ligands, and 1c produced the highest molecular weight copolymers. Complex 1c also promoted copolymerization of ethylene and BuAl protected 10-undecen-1-ol with high activity (~2000 kg·mol·h), affording hydroxy-functionalized ultrahigh molecular weight polyethylene. The hydroxy content of the copolymers obtained was controllable by changing comonomer feed ratio. The introduction of a small amount of hydroxy group can alter the surface properties of polyethylene. [ABSTRACT FROM AUTHOR]

[t-BuNSiMe2(2,7-t-Bu2Flu)]ZrMe2 and [t-BuNSiMe2(3,6-t-Bu2Flu)]ZrMe2 were synthesized, and the solid structure of complex [t-BuNSiMe2(2,7-t-2Flu)]ZrMe2 was elucidated by single crystal X-ray analysis. These complexes were applied for propylene polymerization using dried modified methylaluminoxane as a cocatalyst at 0°C and 20°C in toluene. Both systems did not show activity at 0°C, but they conducted the polymerization at 20°C. The introduction of t-butyl substituents to the fluorenyl ligand improved the activity more than six times regardless of the position of the substituents, and both systems gave low molecular weight polypropylenes (PP) with narrow molecular weight distribution. The introduction of t-butyl substituents also improved the syndiospecificity and [t-BuNSiMe2(3,6-t-Bu2Flu)]ZrMe2 gave highly syndiotactic PP with the syndiotactic pentad of 0.91 and the melting point of 145°C. [ABSTRACT FROM AUTHOR]