Synergistic Effects of Pt and Cd Codoping to Icosahedral Au13 Superatoms

We synthesized a new trimetallic cluster [PtCdAu23(SC2H4Ph)18]−, which has an icosahedral Pt@CdAu11 superatomic core with eight electrons, and investigated how the electronic structure and optical properties of the Au@Au12 superatomic core of [Au25(SC2H4Ph)18]− are affected by codoping of group X and XII atoms. Spectroscopic and electrochemical measurements showed that the HOMO–LUMO (HL) gap of Pt@CdAu11 is larger than that of Au@Au12 and that the photoluminescence quantum yield (PLQY) of Pt@CdAu11 is 46 times larger than that of Au@Au12. To shed light on the origin of the codoping effects, a comparison was made with monodoped clusters [CdAu24(SC2H4Ph)18]0 and [PtAu24(SC2H4Ph)18]2– having the Au@CdAu11 and Pt@Au12 superatomic cores, respectively. The results revealed that the increment of the HL gap of Pt@CdAu11 is mainly because of Pt doping, while the doping of Pt and Cd synergistically enhances the PLQY of Pt@CdAu11.