title: o-Phenylene-bridged Cp/sulfonamido titanium complexes for ethylene/1-octene copolymerization.
abstract: The Suzuki-coupling reaction of 2-(dihydroxyboryl)-3,4-dimethyl-2-cyclopenten-1-one and 2-(dihydroxyboryl)-3-methyl-2-cyclopenten-1-one with 2-bromoaniline derivatives affords cyclopentenone compounds from which cyclopentadiene compounds, 4,6-R'(2)-2-(2,5-Me2C5H3)C6H2NH2 and 4,6-R'(2)-2-(2,3,5-Me3C5H2)C6H2NH2 are prepared. After sulfonation of the -NH2 group with p-TsCl, metallation is carried out by successive addition of Ti(NMe2)4 and Me2SiCl2 affording o-phenylene-bridged Cp/sulfonamido titanium dichloride complexes, [4,6-R'(2)-2-(2,5-Me2C5H2)C6H2NSO2C6H4CH3)]TiCl2 (R'=H, ; R'=Me, ; R'=F, ) and [4,6-R'(2)-2-(2,3,5-Me3C5H)C6H2NSO2C6H4CH3)]TiCl2 (R'=H, ; R'=Me, ; R'=F, ). The molecular structures of and [2-(2,5-Me2C5H2)C6H4NSO2C6H4CH3)]Ti(NMe2)2 are determined by X-ray crystallography. The Cp(centroid)-Ti-N angle in is smaller (100.90 degrees) than that observed for the CGC (constrained-geometry catalyst), [Me2Si(eta5-Me4Cp)(NtBu)]TiCl2 (107.6 degrees) indicating a more "constrained feature" in than in the CGC. Complex shows the highest activity among the newly prepared complexes in ethylene/1-octene copolymerization but it is slightly inferior to the CGC in terms of activity, comonomer-incorporation ability, and molecular weight of the obtained polymers.
authors.affiliation: Department of Molecular Science and Technology, Ajou University, Suwon, 443-749, Korea.
authors.forename: Dae June
authors.initials: DJ
authors.lastname: Joe
authors.forename: Chun Ji
authors.initials: CJ
authors.lastname: Wu
authors.forename: Taekki
authors.initials: T
authors.lastname: Bok
authors.forename: Eun Jung
authors.initials: EJ
authors.lastname: Lee
authors.forename: Choong Hoon
authors.initials: CH
authors.lastname: Lee
authors.forename: Won-Sik
authors.initials: WS
authors.lastname: Han
authors.forename: Sang Ook
authors.initials: SO
authors.lastname: Kang
authors.forename: Bun Yeoul
authors.initials: BY
authors.lastname: Lee