Synthesis, Structure, and 1-Hexene Polymerization Catalytic Ability of Group 5 Metal Complexes Incorporating an [OSSO]-Type Ligand
2013; American Chemical Society; Volume: 3; Issue: 8 Linguagem: Inglês
10.1021/cs4003996
ISSN2155-5435
AutoresTomoyuki Toda, Norio Nakata, Tsukasa Matsuo, Akihiko Ishii,
Tópico(s)Organoboron and organosilicon chemistry
ResumoGroup 5 metal complexes bearing an [OSSO]-type bis(phenolate) ligand have been successfully prepared by the reaction of a bis(phenol) compound 3 or its dilithio salt 6 with VO(OPr)3, NbCl5, or TaCl5. X-ray crystallographic analyses revealed the monomeric nature of the resulting complexes, [OSSO]VO(OPr) (5), [OSSO]NbCl3 (7), and [OSSO]TaCl3 (8), where the metal centers adopted cis-α configurations of the [OSSO] tetradentate ligand. The tantalum(V) complex 8 with iBu3Al/(Ph3C)[B(C6F5)4] as an activator catalyzed the polymerization of 1-hexene to provide completely isotactic poly(1-hexene), with a narrow molecular weight distribution ([mmmm] > 95%, Mw = 9100 g mol–1, PDI = 1.6); this is the first group 5 metal catalyst for α-olefin polymerization to afford a highly isospecific polymer.
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