Doping-Mediated Energy-Level Engineering of M@Au 12 Superatoms (M=Pd, Pt, Rh, Ir) for Efficient Photoluminescence and Photocatalysis.

We synthesized a series of MAu 12 (dppe) 5 Cl 2 (MAu 12 ; M=Au, Pd, Pt, Rh, or Ir; dppe=1,2-bis(diphenylphosphino)ethane), which have icosahedral M@Au 12 superatomic cores, and systematically investigated their electronic structures, photoluminescence (PL) and photocatalytic properties. The energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) was expanded when doping an M element positioned at the lower left of the periodic table. The PL quantum yield was enhanced with an increase in the HOMO-LUMO gap and reached 0.46-0.67 for MAu 12 (M=Pt, Rh, or Ir) under deaerated conditions. The bright PLs from MAu 12 (M=Pt, Rh, or Ir) were assigned to phosphorescence based on quenching by O 2 . MAu 12 (M=Pt, Rh, or Ir) acted as a more efficient and stable photocatalyst than Au 13 for intramolecular [2+2] cycloaddition of bisenone via the oxidative quenching cycle. This study provides rational guides for designing photoluminescent and photocatalytic gold superatoms by the doping of heterometal elements.