title: Preparation of half-metallocenes of thiophene-fused and tetrahydroquinoline-linked cyclopentadienyl ligands for ethylene/α-olefin copolymerization.
abstract: Directed ortho-lithiation of the lithium carbamates generated from tetrahydroquinoline or tetrahydroquinaldine enables one-step preparation of thiophene-fused and tetrahydroquinoline-linked cyclopentadienes [2-R(1)-3-R(2)-4,5-dimethyl-6-(2-R(3)-2,3,4,5-tetrahydroquinolin-8-yl)-4H-cyclopenta[b]thiophene (R(1), R(2), R(3) = H or methyl)], from which titanium(iv) and zirconium(iv) complexes are prepared. The molecular structures of Me(2)Ti-complexes (12, R(1) = R(2) = Me, R(3) = H; 14, R(1) = R(2) = R(3) = Me) and Cl(2)Zr-complex (17, R(1) = R(2) = Me, R(3) = H) are determined by X-ray crystallography. The Me(2)Ti-complexes, 14 and 15 (R(1) = R(3) = Me, R(2) = H) show excellent activities (62 and 54 × 10(6) g/molTi·h) in ethylene/1-octene copolymerization, even when activated with small amount of MAO (Al/Ti = 1000).
authors.affiliation: Department of Molecular Science and Technology, Ajou University, Suwon, 443-749, Korea.
authors.forename: Ji Hae
authors.initials: JH
authors.lastname: Park
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Do
authors.forename: Anish
authors.initials: A
authors.lastname: Cyriac
authors.forename: Hoseop
authors.initials: H
authors.lastname: Yun
authors.forename: Bun Yeoul
authors.initials: BY
authors.lastname: Lee