Polymerization Catalysis

Although polyolefins are the world’s most common synthetic polymers, there are still numerous opportunities for innovations in their synthesis, processing, and materials properties. Polyolefins are such attractive materials because they could be produced from a broad range of inexpensive building blocks and their physical characteristics are highly tunable. A major research thrust in the Do group is to develop stimuli-responsive catalysts that are capable of yielding different polyolefin products from a common catalyst platform, which would streamline polymer synthesis by providing a simple way to prepare user-defined materials. Toward this goal, our lab has developed several late transition metal catalyst systems that could be switched by interchanging their pendent cations. We are investigating how to leverage the unique chemical properties of secondary metals to favor polymerization pathways that are inaccessible using conventional catalysts. We also wish to discover new polymerization methods to synthesize environmentally friendly polymers derived from sustainable resources. Novel catalyst design strategies, such as the application of outer coordination sphere and/or non-covalent interactions, will also be explored.

Small-Molecule Intracellular Catalysis

Small-molecule intracellular metal catalysts (SIMCats) are molecular inorganic complexes that catalyze bioorthogonal reactions inside living environments and are non-toxic to their biological hosts. The most well-known SIMCats are copper catalysts that promote click reactions commonly used in bioconjugation and related applications. Similar to artificial metalloenzymes, SIMCats provide opportunities for scientists to carry out new to nature reactions, which could be useful for enhancing native biochemical functions or accessing novel therapeutic modes of action (among other applications). In our SIMCat discovery program, we are developing protocols to efficiently screen and optimize catalyst candidates for their biocompatibility and methods to study their chemical and biological behavior inside cells and organisms. We are currently focused on studying SIMCats that mediate transfer hydrogenation catalysis but other catalytic transformations are also of interest. Our ultimate research goal is to create SIMCat-based technologies that either improve human health or enable green chemical synthesis. We expect that this work will lead to new fundamental knowledge as well as practical solutions to important biological problems.