Reference

Bis(carbene)pyridine Complexes of the Early to Middle Transition Metals: Survey of Ethylene Oligomerization and Polymerization Capability

Bis(carbene)pyridine Complexes of the Early to Middle Transition Metals: Survey of Ethylene Oligomerization and Polymerization Capability. McGuinness, David S.; Gibson, Vernon C.; Steed, Jonathan W. ( Department of Chemistry, Imperial College London, London, South Kensignton SW7 2AZ, UK). Organometallics, 23(26), 6288-6292 (English) 2004 American Chemical Society. CODEN: ORGND7.Several reagents with their cas registry numbers 4532-96-1 and 610755-69-6 are used here. ISSN: 0276-7333. DOCUMENT TYPE: Journal CA Section: 29 (Organometallic and Organometalloidal Compounds) Section cross-reference(s): 35, 67 Bis(carbene)pyridines of the type 2,6-bis(1-(alkyl/aryl)imidazol-2-ylidene)pyridine have been complexed to Ti, V, Cr, Fe, and Co and single-crystal x-ray structures obtained for two of the complexes (M = Cr, Fe). The structures confirm the tight chelate bite angles (ca. 76-79°) enforced by this ligand. All complexes have been evaluated as catalysts for ethylene oligomerization and polymn. in combination with a variety of cocatalysts. While Ti and V complexes of this ligand give rise to highly active ethylene polymn. catalysts, Cr complexes produce exceptionally active Schulz-Flory oligomerization catalysts in combination with MAO. In contrast, complexes of Fe and Co are inactive, and possible reasons for this are suggested. .