(AuAg)₄₄(SPh^tBu)₂₆ versus (AuAg)₄₄(SPhF₂)₃₀: Tailoring the Geometric Structures and Optical Properties of Nanocluster Analogues

Abstract

Monolayer-protected nanoclusters are ideal models for understanding the correlations between structures and properties of inorganic nanoparticles, especially for those molecules with identical sizes but comparable structures. Here, we controllably prepared and structurally determined a valence-neutral Au24+x Ag20‑x (SPh t Bu)26 (0 < x < 4) nanocluster with comparable structure features to a well-known Au12Ag32(SPhF2)30 cluster. The Au24+x Ag20‑x (SPh t Bu)26 cluster contained a hollow Au12@M20 metallic kernel (M = Au/Ag), 12 Au1(SR)2 staples, and two bridging SR molecules, and its average molecular formula was determined to be Au26.3Ag17.7(SPh t Bu)26, as evidenced by X-ray crystallography and electrospray ionization mass spectrometry. Because of the ligand effect and the asymmetrical arrangement of the Au dopants in the dodecahedral cage, the Au24+x Ag20‑x (SPh t Bu)26 nanocluster exhibited lower molecular symmetry relative to Au12Ag32(SPhF2)30 in terms of the dodecahedral kernel and motif shell structures. Besides, the strong π–π interaction in Au24+x Ag20‑x (SPh t Bu)26 contributed to its enhanced photoluminescence intensity compared with Au12Ag32(SPhF2)30. The study, herein, extends the 44-metal-atom cluster family, thereby enabling us to better understand the correlations between their structures and properties at the atomic level.

Tailoring the subshell and electronic structure of an atomically precise AuAg alloy nanocluster

“…9 Several effective approaches have been documented to achieve this goal, including modifying the synthesis processes, the utilization of diverse protective ligands, and doping, among others. 8,10–16 By employing these methodologies, nanoclusters sharing comparable overall structures have been successfully manipulated to achieve varying surface and/or core arrangements. 17–20 This accomplishment has enabled the tailoring of the properties of nanoclusters, including catalytic behavior, 21–23 luminescence, 24–27 chirality, 28–33 and more.…”