CATL 31 |
| Over thirty Ti and Zr single-site olefin polymerization catalysts containing mixed cyclopentadienyl/aryloxide ligation were studied using density functional theory and compared to experimental data in order to develop structure-activity correlations. For some of the catalysts, transition state analysis for catalyst activation, chain initiation, chain propagation, chain transfer, chain termination, and catalyst deactivation steps was performed. For all of the catalysts, a series of chemical descriptors based on ground state energies and geometries was used to better understand reactivity trends for different catalytic steps. We investigated the effects of solvent, ligand structure, counterion, and metal on the reaction rates, polymer molecular weights, and catalyst descriptors. For some catalysts, the rate of chain initiation was approximately one thousand times slower than chain propagation. For other catalysts, the rates of chain initiation and propagation were approximately equal. A model was developed to explain these results. |
|
High-Throughput and General Catalysis
9:00 AM-12:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Rm. 222, Oral
Catalysis & Surface Science Secretariat |