Manipulation on metal nanoclusters (NCs) in an atom-by-atom manner has long been desired, as the resulting series of NCs can provide insightful understanding of how a single atom affects the structures and properties. Firstly, we report crystallizations of Au21, Au22, Au22Cd1 and Au24 (ligand = adamantanethiolate) with an atom-by-atom evolution and the same ligand protection. The slightly change in NC structure with one atom difference brings about dramatically changed optical properties. The photoexcited carrier lifetime demonstrates that the optical properties and excited state relaxation are highly sensitive at the single atom level. By contrast, little change in both ionization potential and electron affinity is found in this series by theoretical calculations, indicating the electronic properties are independent of adding a single atom in this series. Secondly, we report a central atom engineering approach to achieve Au@Cu14 NCs with very high phosphorescence (quantum yield QY=71.3%) in non-degassed solution at room temperature. When the single-Au-atom is replaced by Cl, the ambient QY in solution decreases proportionally with the ratio of Au/(Au + Cl). The central Au atom leads to highly efficient singlet-to-triplet intersystem crossing and the outside rigid Cu(I) complex cage suppression of nonradiative energy loss. The phosphorescence from Au@Cu14 is much less sensitive to air, which is important for lighting and biomedical applications.

Single atom manipulation on metal nanoclusters for properties control

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.