Single-electron charging and ultrafast dynamics of bimetallic Au 144− x Ag x (PET) 60 nanoclusters

Alloying is an important strategy in tailoring the functionality of materials. In metal nanoclusters (NCs), the introduction of a heterometal leads to alloy nanoclusters that often outperform the homometal ones in terms of the physical and chemical properties. In this work, a series of four M 144 (PET) 60 alloy NCs (where, M = Au/Ag, PET = −SCH 2 CH 2 Ph) are synthesized and characterized. The silver doping into the homogold template (Au 144 ) leads to more prominent optical absorption features in the steady-state spectrum in the visible range. Femtosecond transient absorption spectroscopy reveals the effect of Ag doping on the electronic relaxation dynamics compared to Au 144 and the pump fluence independent dynamics. Electrochemical results reflect a narrowing of HOMO—LUMO gap ( E g ) induced by Ag doping. A temperature dependence of the single-electron charging is also observed for the series of alloy NCs, in which the E g values of the alloy NCs enlarge as the temperature decreases, which is characteristic of semiconducting behavior.