title: Fluorine- and trimethylsilyl-containing phenoxy--imine Ti complex for highly syndiotactic living polypropylenes with extremely high melting temperatures.
abstract: A fluorine- and trimethylsilyl-containing phenoxy-imine titanium complex was synthesized and the structure was determined by an X-ray analysis. The complex on activation with MAO initiates highly controlled syndiospecific living propylene polymerization to form extremely high Tm syndiotactic polypropylenes (Mw/Mn = 1.05-1.08, Tm = 156-152 degrees C) at 0 or 25 degrees C. Moreover, at 50 degrees C, the complex afforded monodisperse syndiotactic polypropylene with very high Tm's of 149, 150 degrees C. In contrast, complexes having a t-Bu group instead of the silyl group provided lower tacticity polymers with much lower Tm's. In addition, we revealed the substituent effect that plays a key role for the highly controlled syndiospecific polymerization displayed by the catalyst.
authors.affiliation: R & D Center, Mitsui Chemicals, Inc., 580-32 Nagaura, Sodegaura, Chiba, 299-0265, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Mitani
authors.forename: Rieko
authors.initials: R
authors.lastname: Furuyama
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Mohri
authors.forename: Junji
authors.initials: J
authors.lastname: Saito
authors.forename: Seiichi
authors.initials: S
authors.lastname: Ishii
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Terao
authors.forename: Norio
authors.initials: N
authors.lastname: Kashiwa
authors.forename: Terunori
authors.initials: T
authors.lastname: Fujita