Chiral Superatomic Nanoclusters Ag₄₇ Induced by the Ligation of Amino Acids

Abstract

Silver nanoclusters containing Ag 0 atoms protected by amino acids were synthesized and characterized.C hiral superatomic silver nanoclusters [Ag 47 L 12 (CC t Bu) 16 ]BF 4 (L = l-/d -valine or l-/d -isoleucine) have been prepared by reducing AgCC t Bu and amino acids (AAs) with NaBH 4 .S ingle crystal X-ray diffraction revealed that these clusters have T symmetry,a nd the Ag 47 metal kernel can be viewed as at etracapped truncated tetrahedron (Ag 17 )s urrounded with six W-shaped Ag 5 units.T he clusters are homochirala s evidenced by CD measurements.Asfor the strong CD signals, large contributions are found from the occupied Ag s,ps tates (superatomic Dstates) near the Fermi level. Electron counting revealed that these clusters are 18-electron systems,s uggesting they are superatomic clusters.T he superatomic nature with a1 S 2 1P 6 1D 10 configuration was supported by DFT calculations.T his work paves the wayo ft aking AAs as facile chiral induction agents for the synthesis of metal nanoclusters.

Small symmetry-breaking triggering large chiroptical responses of Ag70 nanoclusters

“…The main peaks that appear in the UV-Vis absorption spectrum of Rac-Ag 70 (Fig. 3a ) are well reproduced in the theoretically simulated spectrum (the calculations are described in the Methods section and Supplementary Information ), further confirming the structure and the number of valence electrons of this NC 7 , 13 . The efficient transitions of the low-energy absorption peaks mainly involve metal-based transitions (Supplementary Figs.…”

Recent Progress in the Simulation of Chiral Systems with Real Time Propagation Methods

“…Similarly, Liu et al [122] . used RT‐TDDFT calculations to verify their experimental results on the CD signatures of chiral super atomic silver nanoclusters also using the GPAW program [121] …”

“…[119] The advantages of RT-TDDFT, its scaling and the ability to deal with high density of states, were well demonstrated by Makkonen et al, [120] who applied the method to nano scale metal-organic clusters containing up to 1074 atoms, albeit using the reference point dependent length gauge formulation, and the GPAW program. [121] Similarly, Liu et al [122] used RT-TDDFT calculations to verify their experimental results on the CD signatures of chiral super atomic silver nanoclusters also using the GPAW program. [121] Up to now, there is only one publication of RT-TDDFT applied to ROA by Mattiat and Luber [87] who include a detailed analysis of the issues of gauge (origin) dependence.…”

Site-specific doping of silver atoms into a Au25 nanocluster as directed by ligand binding preferences

“…33 It is well known that surface organic ligands are critical in the formation of atomically precise metal nanoclusters. 6,[34][35][36][37][38][39][40] It has been found that the electronic nature, coordination preference, and bulkiness of ligands can have significant effects on the structures and properties of the clusters. [41][42][43][44][45] In order to achieve site-specified doping of silver into a gold nanocluster, we develop a strategy to control the atomic arrangement through the combination of ligands with different ligating preferences.…”