Functional metal-organic frameworks for catalysis, sensing, and separations
Metal-organic frameworks (MOFs) are 3-dimensional polymeric systems comprised of organic and inorganic subunits connected by self-assembled metal-ligand bonds. These materials provide a unique platform for the design of functional materials owing to their uniform structures, high degree of tunability, and propensity for guest-accessible porosity. In particular, the presence of organic building blocks allows for facile tuning and functionalization of these materials. We are currently developing new synthetic methods for incorporation of well-defined reactive sites into MOF matrices to study the effects of reactive site confinement and design more efficient materials for catalytic small molecule activation and selective ion and small molecule capture/sensing.
Another aspect of our research deals with understanding how the electronic and steric properties of bridging ligands affect the reactivity of bimetallic complexes. For example, in contrast to mononuclear species, dinuclear gold complexes supported by bridging phosphonium ylide ligands undergo facile oxidative addition of a number of small molecules. This reactivity stems from the use of the rigid, strongly donating bridging ligands which increase metal nucleophilicity and support metal-metal bonding interactions. We are currently exploring how modulation of the electronic and steric properties of phosphonium ylides and related classes of bridging ligands can be used to gain control over bond activation and formation processes in homo- and heterodinuclear complexes.