This project, carried out by Professors Leslie Butler and Randall Hall of Louisiana State University and their students, and Dr. Larry Simeral of the Albemarle Corporation, and supported by Analytical and Surface Chemistry, uses nuclear magnetic resonance spectrometry based on the nuclei 2H, 17O, and 27Al to characterize the active catalytic site of methylaluminoxane, a co-catalyst used in new generation Ziegler-Natta catalysis for olefin polymerization. The 27Al sites exhibit large quadrupolar interactions that require special methods developed in the PI's laboratory for successful measurement of the NMR spectra. Density functional and molecular orbital calculations are used to model the observed quadrupolar interactions, and then the observed NMR spectra are correlated with the calculated structures. This GOALI project contains an academic and industrial collaboration between the PIs at Louisiana State University and scientists at Albemarle Corporation.
Ziegler Natta catalysts are used in industrially important reactions that produce polymers and plastics. A catalyst involves a specific site on a molecule where the reaction occurs. Despite the wide use of the Ziegler Natta catalyst based on a compound called methylaluminoxane, the nature of the catalytic site is unknown. Small differences in catalyst preparation lead to large differences in catalytic efficiency, and there is therefore much interest in determining the nature of that site. Professors Leslie Butler and Randall Hall of Louisiana State University and their students will use unique spectroscopic techniques to establish the nature of that site, in collaborative work with scientists at Albemarle Corporation, a producer and user of the catalytic material.
