Professor YuYe Tong of Georgetown University is supported by the Experimental Physical Chemistry program to apply nuclear magnetic resonance (NMR) spectroscopy to investigate metal-ligand bonding interactions in alkanechalcogenol-protected metal (Au, Ag, Pd, and Pt) nanoparticles and quantum dots. A general aim is to advance understanding at the molecular level of factors that govern charge transfer in these nanoscale systems. NMR spectroscopy measurements are being performed on metal nanoparticles in solution that are held in a fixed charge state through electrochemical potential control. The spectroscopic information is being used to determine Fermi level local density of state values in relation to ligand structure and electronic interactions between the metal nanoparticle and the contacting element (S, Se, or Te). The work is developing multinuclear (i.e., 13C, 77Se, 109Ag, 195Pt, 125Te) NMR strategies for general application to nanostructured materials.
Advances being made by the Tong group through combined applications of NMR spectroscopy and electrochemistry are impacting areas of technological importance, in particular the field of molecular scale electronics. The research is providing insights into chemical bonding interactions between metal nanoparticles and ligands attached to the surface. The work has ramifications in the design of molecular electronic materials.