A Valence Bond Analysis of Olefin Polymerization Catalysts Timothy K. Firman and Tom Ziegler.

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Presentation transcript:

A Valence Bond Analysis of Olefin Polymerization Catalysts Timothy K. Firman and Tom Ziegler

Olefin Polymerization  Very important industrial processes  Many non-metallocene catalysts have recently been discovered  A variety of d 0 homogeneous catalysts are known, as well as some which are d 6, d 7, or d 8.  A better understanding of the effects of changing metal and ligands will lead to better catalysts

Second Row Transition Metals

Addition of an Amine Group

Linked Ligands Electronically analogous to the previous model Ethyl bridges will restrict geometry, increasing uptake energy by lowering reorganization costs

Localized Orbitals Olefin insertion

More Localized Orbitals Chain Termination (via  -hydride transfer)

Future Work  Analysis of amide/amine systems which include constraining ligands  Further investigation of electronic effects of ligands on transition state energies  Exploration of  -conjugated ring ligands with variable ligand-metal bond order.

Acknowledgements Tom ZieglerRochus Schmid Tom GilbertSergei Patchkovskii The Ziegler Group NSERC and Nova