Abstract:

Atomically precise metal nanoclusters (MNCs) are a class of materials sharing properties with molecular complexes and bulk nanoparticles. Their structure consists of a metal core and an organometallic ligand shell comprised of multiple MxRx+1 staple motifs, where M is a metal and R is an organic ligand. In the context of self-assembled materials, MNCs are attractive due to their high monodispersity brough upon by their atomic precision. This in turn may limit the number of defects that are otherwise present in larger plasmonic nanoparticle assembled materials. However, the surface of MNCs is quite dynamic, for the surface ligands readily undergo ligand exchange reactions that can alter the structure and function of the MNCs. Understanding the dynamic surface is crucial to achieve higher-order self-assembled materials. There are many ways to study MNC surface dynamics, but 1H NMR provides highly sensitive structural information about the organometallic ligand shell. Recent work from Thomas Bürgi’s group at the University of Geneva utilizes variable temperature 1H NMR and 2D Exchange Spectroscopy to study the intercluster and interligand dynamics of a model silver nanocluster species ([Ag25(DMBT)18]-). This work gives insight into how the ligand shell impacts the stability of the MNCs, with further details to be presented during this talk.