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Synthetic Models of Weak Attractive Ligand‐Polymer Interactions in Olefin Polymerization Catalysts
Author(s) -
Chan Michael C. W.
Publication year - 2007
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200700322
Subject(s) - substituent , chemistry , polymerization , ligand (biochemistry) , polymer chemistry , olefin fiber , intramolecular force , catalysis , polyolefin , agostic interaction , crystallography , polymer , metallocene , photochemistry , stereochemistry , metal , organic chemistry , biochemistry , receptor , layer (electronics)
The subject of extremely weak hydrogen bonds such as CH···FC remains a contentious and topical area of research. The design and synthesis of a family of Group‐4 post‐metallocene catalysts supported by F‐functionalized tridentate ligands that impose the fluorine substituent(s) in close proximity to the metal center is described, and for the first time, the elusive CH···FC interaction is characterized by a neutron diffraction study. The nature of the weak intramolecular CH···FC contacts in these complexes in solution and in the solid state is probed using multinuclear NMR spectroscopy in tandem with neutron and X‐ray crystallography. These CH···FC interactions are important with regards to design implications and potential applications in olefin polymerization catalysts because they corroborate the proposed ortho‐F···H(β) ligand–polymer contacts derived from density functional theory calculations for the Group 4 fluorinated phenoxyimine catalysts. Compared with the established agostic and cocatalyst–metal contacts, weak attractive non‐covalent interactions between a ‘non‐innocent’ ligand and the polymer chain is a novel concept in polyolefin catalysis.