Frustrated Lewis Pairs
Frustrated Lewis Pairs (FLPs) are infamous in inorganic chemistry for their unique reactivity towards small molecules, such as dihydrogen and carbon dioxide. Reactivity arises from the unquenched Lewis acid and base centers present, bearing bulky groups that prevent them from forming an adduct. This distinctive FLP reactivity has since been applied to hydrogenation reactions and small molecule activations.
Extending this concept to polymer science has permitted the growth of a new class of responsive, functional, self-healing materials. Our team developed the first polymeric version of FLPs – first forming polystyrene derivatives and later polymethyl methacrylates. Our research focuses on the design and synthesis of novel sterically hindered Lewis acid/base-containing monomers and subsequent incorporation of these into polymer chains. Through careful modification of substituents surrounding the Lewis centers and of the polymer backbone itself, we can tune the reactivity of the resultant polymeric FLPs. Our initial efforts show the transformation of our poly(FLP)s from a solution to a gel, triggered by the addition of a suitable small molecule. This gives rise to a heat-responsive material that can self-heal.
Wang, M.; Nudelman, F.; Matthes, R.; Shaver, M. P. “Frustrated Lewis Pair Polymers as Responsive Self-Healing Gels” J. Am. Chem. Soc. 2017, 139 (40), 14232
Yolsal, U.; Wang, M.; Royer, J. R.; Shaver, M. P.* “Rheological Characterization of Polymeric Frustrated Lewis Pair Networks” Macromolecules, 2019, 52 (9), 3417