(AuAg)144(SR)60 alloy nanomolecules

Abstract

(Au-Ag)₁₄₄(SR)₆₀ alloy nanomolecules were synthesized and characterized by ESI mass spectrometry to atomic precision. The number of Ag atoms can be varied by changing the incoming metal ratio and plateaus at ∼60. UV-vis data demonstrates that the electronic structure of the nanomolecules can be tuned by incorporation of silver atoms. Based on the proposed 3-shell structure of Au₁₄₄(SR)₆₀, we hypothesize that the Ag atoms are selectively incorporated in to the symmetry equivalent 60-atom shell—having Au₁₂, Au₄₂, Ag₆₀ concentric shells with 30 –SR–Au–SR– protecting units.