[(Ph)₂nacnac]MCl₂(THF)₂ (M = Ti, V, Cr):  A New Class of Homogeneous Olefin Polymerization Catalysts Featuring β-Diiminate Ligands

Abstract

1c)) were prepared and their structures determined by X-ray diffraction. In the presence of excess methylaluminoxane (MAO), 1a-c catalyzed the homopolymerization of ethylene and the copolymerization of ethylene with R-olefins.

Synthesis and Structure of the First Non‐Metallocene TiIII Fluoride Complex LTiF2·2Me3SnCl Supported by a β‐Diketiminato Ligand

“…The TiϪCl bond length is similar to those found in the literature for β-diketiminato complexes of Ti III (TiϪCl 2.395 Å [7] ).…”

“…More pertinent to this study, however, is the high catalytic activity displayed by pentamethylcyclop- [a] Institut für Anorganische Chemie, Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany Fax: (internat.) ϩ 49-551/393373 E-mail: hroesky@gwdg.de entadienyl-substituted titanium fluorides in combination with methylaluminoxane (MAO) in the polymerization of styrene: [6] β-diketiminato complexes of Ti III with the general formula LTiCl 2 , [7,8] in the presence of excess methylaluminoxane [7] or B(C 6 F 5 ) 3 , [8] catalyse the homopolymerization of ethylene and the copolymerization of ethylene with α-olefins. Thus, our interest in the chemistry of titanium fluoride complexes stems from the potential use of Ti III fluoride complexes supported by a new β-diketiminato ligand as a novel olefin polymerisation catalyst.…”

Ethylene Polymerization with Silica-Supported Cr[N(SiMe3)2]3/Alumoxane Catalyst

“…[5][6][7][8][9][10][11][12] Recently, non-cyclopentadienyl chromium catalysts have been reported. [13][14][15][16][17][18][19][20][21][22] These homogeneous catalysts have moderate to high activity depending on the ligand structures. We have been exploring noncyclopentadienyl chromium catalysts because different characteristics could be expected for chromium as a group 6 element from the group 4 elements like titanium and zirconium, the group 8 element like iron and group 10 elements like nickel and palladium.…”

Cr Complexes of Nitrogen Donor Ligands for Olefin Oligomerisation and Polymerisation

“…Closely related complexes 20 and 21 were reported by the same authors [27]. Both are inactive in the presence of MAO but lead to high molecular weight polyethylene with 25 Chromium complexes of b-diketiminate (NacNac) ligands, both mono-and bisligand, were introduced by Theopold [29] and Gibson [30]. These complexes led to moderate activities for ethylene polymerisation upon activation with Et 2 AlCl or MAO (with Et 2 AlCl generally superior) [1].…”