title: [2]Borametallocenophanes of Zr and Hf: synthesis, structure, and polymerization activity.
abstract: The first [2]borametallocenophanes of Zr and Hf are reported, which were obtained from 1,2-bis(dimethylamino)-1,2-dicyclopentadienyldiborane(4). The constitution of these complexes in solution and, for the Hf complex, in the crystalline state is discussed. The title complexes were studied as Ziegler-Natta-type catalyst precursors for the polymerization of ethylene. Both complexes produced PE of high molecular mass up to 1.6 x 106 g/mol, and very interestingly, the Hf complex proved to be as active as its Zr analogue.
authors.affiliation: Institut für Anorganische Chemie, Bayerische Julius-Maximillians Universität Würzburg, Am Hubland, 97074 Würzburg, Germany. h.braunschweig@mail.uni-wuerzburg.de
authors.forename: Holger
authors.initials: H
authors.lastname: Braunschweig
authors.forename: Manuela
authors.initials: M
authors.lastname: Gross
authors.forename: Mario
authors.initials: M
authors.lastname: Kraft
authors.forename: Marc O
authors.initials: MO
authors.lastname: Kristen
authors.forename: Dirk
authors.initials: D
authors.lastname: Leusser