Mechanistic Investigations of Olefin Polymerizations and Selective Oligomerizations

点击翻译按钮获取中文摘要

This award in the Inorganic, Bioinorganic and Organometallic Chemistry program supports research by Professor Lawrence B. Sita at the Univesity of Maryland at College Park to use a monocyclopentadienyl, amidinate ligand combination to impart significant kinetic stability to a variety of early transition metal alkyl complexes bearing beta-hydrogens. The primary objectives are to utilize neutral and cationic group 4 and 5 monocyclopentadienyl, monoamidinate metal alkyl complexes as a means to investigate mechanistic aspects of Ziegler-Natta polymerization and the highly selective trimerization of ethylene and alpha-olefins. This work seeks to determine how intra- and intermolecular dynamic processes can be harnessed to expand the structural and microstructural range of polyolefin materials that can be prepared through the Ziegler-Natta process. The work will test and validate a new paradigm for accessing a wide range of polyolefin microstructures through two-state bimolecular control that is based on degenerative-transfer living Ziegler-Natta polymerization. For the selective oligomerization of alpha-olefins, the proposed studies will contribute to an understanding of the factors that can serve to achieve both higher activities and selectivities in a new generation of catalysts. The broader impact of this work is the potential development of more efficient catalysts and new polyolefin materials that will be beneficial to both the world economy and society. The proposed work will provide an important vehicle by which future generations of undergraduates, graduate students, and postdoctoral researchers can be trained with the promotion of diversity in mind.