Multi-anionic Pincer Ligand Catalysts and Ring Expansion Alkyne Metathesis Polymerization (REAMP)

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The Chemical Catalysis and the Macromolecular, Supramolecular and Nanochemistry Programs of the Chemistry Division support the project by Professor Adam Veige of the University of Florida. Linear polymer are useful in numerous applications due to their electrical conductivity, optical nonlinearity, photoconductivity, gas permeability, and liquid-crystallinity. The Veige group seeks to discover new catalysts that produce cyclic versions of these polymers in order to explore new opportunities to further advance their materials properties. Because of technical problems, cyclic polymers are not currently commercially available. Professor Veige and his coworkers are focusing on making the catalysts for cyclic polymerizations more rugged and efficient. This project is also providing hands-on training for young aspiring chemists through the undergraduate research program. The Veige group hosts the annual "Chemistry Day at the Mall" event, which involves fifty graduate and undergraduate students exhibiting 25 chemistry demonstrations to nearly 500 children and their parents annually. This project focuses on the synthesis and characterization of catalysts for cyclic polymer synthesis. Ring expansion alkyne metathesis polymerization (REAMP) is unknown. The Veige group aims to prepare a tethered tungsten-alkylidyne capable of initiating the unprecedented ring expansion of cyclic alkynes. Highly nucleophilic metal-carbon multiple bonds can ring open cyclic alkenes to produce cyclic polymers. Two new pincer ligand designs may provide access to nucleophilic tungsten-alkylidynes for REMP. Finally, current catalyst synthesis routes are tedious and inefficient, so the research team seeks to synthesize highly effective Mo-based catalysts for stereoselective cyclic polymer synthesis from commercially available starting materials. Elucidating efficient synthetic strategies for ring expansion catalysts may help to realize the potential of cyclic polymers in advanced manufacturing.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.