(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 Au(144)(SR)(60), we hypothesize that the Ag atoms are selectively incorporated in to the symmetry equivalent 60-atom shell-having Au(12), Au(42), Ag(60) concentric shells with 30 -SR-Au-SR- protecting units.

The SERS effect in coordination chemistry

“…More recently, Dass et al [94,95] showed a very interesting synthetic method, encompassing the evolution from molecule-like to plasmon resonance systems, as a function of the number of atoms in the gold cluster. For instance, they have shown that the clusters Au 25 (SR) 18 , Au 38 (SR) 24 , Au 102 (SR) 44 and Au 144 (SR) 60 behave as ultra-small (< 2 nm) thiolated gold nanoparticles, but resembling molecules, while Au 329 (SR) 84 shows a plasmon resonance peak (SR = organothiol).…”

Ag7Au6: A 13‐Atom Alloy Quantum Cluster

“…[10] However, synthesis of atomically precise alloy QCs of various compositions is a challenge. [11] Murray et al synthesized Pd@Au 24 (SR) 18 which was further studied by Negishi et al [ 11b] Negishi et al isolated PdAu 24 (SR) 18 .…”

“…Stable gold cluster molecules of the type Au 11 , [1a] Au 13 , [1b,c] and Au 55 , [1d] have been fascinating and were some of the early molecular nanosystems synthesized. Quantum phenomena such as Coulomb blockade were demonstrated with them.…”

Information on quantum states pervades the visible spectrum of the ubiquitous Au144(SR)60 gold nanocluster

“…Moreover, high stability leads to high reproducibility of experiments. Many groups have studied this compound [12][13][14][15][16] with varying thiolate ligands and, more recently, with noble-metal compositions varying between pure gold and different Au-Ag 17 and Au-Cu 18 alloys. These clusters are notable for their compact symmetrical structure, well-defined electrical capacitance, and optical and electronic properties.…”