With this award, the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry is funding Dr. Jeremiah A. Johnson from Massachusetts Institute of Technology to make a variety of metallic nanoparticles. Nanoparticles with controlled sizes and attached molecular and metallic groups (ligands) have enabled technological innovations in fields ranging from green catalysis and energy conversion to electronics and therapeutics. Despite many advances, the number of methods available to modify the surfaces of nanoparticles is quite small, and each existing method has significant limitations. For example, metal-sulfur bonds, which are by far the most studied linkages are often not sufficiently stable for certain demanding applications Their synthesis is not always straightforward, and they may possess unwanted color/odor. This research examines the use of a variety of new groups on metal nanoparticles in order to develop materials that may be useful in electronics, nanotherapeutics and other applications. The research has a broader impact on the education of undergraduate and graduate students, especially women and underrepresented minorities. The research team is further broadening the impact of their work by including and mentoring high school teachers from the greater Boston/Cambridge area.
This research is focused on the synthesis of novel N-Heterocyclic Carbene (NHC)-metal complexes, new strategies for installation of such NHC-metal complexes onto metallic surfaces, and hybrid organic/inorganic materials that leverage the strength of NHC-metal bonds to achieve stability and versatility. The activities are divided into three independent research thrusts. In the first thrust, functional NHC-gold complexes and nanoparticles are prepared bearing "clickable" functionalities which enable polymerization of alkene-based NHC ligands on gold nanoparticles. In the second thrust, NHC@Au nanoparticles-based hybrid materials are designed to contain block copolymers bearing polyNHC-Au complexes as blocks. These block copolymers are then investigated as templates for the formation of gold nanoparticles. In the third trust, a family of NHC@metal monomer complexes with a variety of metals (e.g. copper, iron, nickel and palladium, is prepared for copolymerization studies that yield novel NHC@metal alloy nanoparticles. The research associated with this work provides new tools for the formation of robust chemical bonds between metals and functional molecules with the potential to have broad impacts across fields including electronics, supported catalysis, nanotherapeutics and green chemistry.
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.
