[C-H...F-C] and Related Non-covalent Interactions in (Carbon-nased)-Chelating Post-Metallocenes: Characterization and Application to Catalysis

Description

Considerable advances have been achieved for post-metallocene catalysts with respect to improved performance and new applications in olefin polymerization. Non-covalent interactions such as C–H‧‧‧F–C between a functionalized non-innocent ligand and the growing polymer chain (or ‘weak attractive ligand–polymer interactions’) can potentially allow control of the reactivity at the polymer chain, but there is little precedent for their exploration. The nature and relevance of C–H‧‧‧F–C interactions is a topical yet controversial issue. Due to the emerging importance and applicability of fluorine substituents, it is desirable to employ spectroscopic methods to probe and elucidate their surrounding environment and connectivity. In this project, the design and preparation of ligand frameworks and the corresponding post-metallocene complexes bearing suitably appended fluorinated (or related hydrogen-bonding acceptor) substituents will be pursued, and strategies to improve catalyst performance will be implemented. Detailed NMR spectroscopic characterization and investigation of intramolecular non-covalent interactions will be undertaken. The underlying objectives are to probe the existence of weak attractive ligand-polymer interactions in the proposed catalysts, examine the consequences of these interactions upon catalytic behavior and polymer properties, and develop novel catalyst systems with attractive characteristics.