Formation of a Pd@Au₁₂ Superatomic Core in Au₂₄Pd₁(SC₁₂H₂₅)₁₈ Probed by ¹⁹⁷Au Mössbauer and Pd K-Edge EXAFS Spectroscopy

Recently, a variety of thiolated gold alloy clusters with well-defined compositions have been synthesized, and the effect of doping on their properties and stability has been studied extensively. We examined the occupation site of the Pd dopant within Au 24 Pd 1 (SC 12 H 25 ) 18 by probing complementarily the local environments of Au and Pd elements using 197 Au Mössbauer and Pd K-edge EXAFS spectroscopy, respectively. The experimental results suggest that the doped single Pd atom is preferentially located at the center of Au 24 Pd 1 (SC 12 H 25 ) 18 to form the superatomic Pd@Au 12 core, which supports recent theoretical predictions. These spectroscopic measurements also clarified intracluster electron transfer from the Pd atom to the surrounding Au atoms.