Chemically Modified Gold Superatoms and Superatomic Molecules

Abstract

Clusters of gold atoms can be viewed as superatoms, in which valence electrons confined in the particles occupy atomic-like, discrete electronic levels. Chemical modification of the gold superatoms and their aggregated molecules (superatomic molecules) with organic ligands is a promising approach for their application as the building units of new functional materials. This account surveys the present status of the rapidly growing field of gold superatoms and superatomic molecules protected by thiolates and phosphines. The major aim of this article is to provide a simple picture for the structure, stability and bonding scheme of chemically modified superatoms and superatomic molecules for the development of a new class of hierarchical materials.

Insight into the Geometric and Electronic Structures of Gold/Silver Superatomic Clusters Based on Icosahedron M13 Units and Their Alloys

“…[64] Recently,s ix-electron superatomic [AuAg 24 (dppm) 3 -(C 6 H 11 S) 17 ] 2 + coprotected by phosphine and thiol ligands was reportedb yZ hu and co-workers( Figure 8A). [65] Interestingly, the shape of [AuAg 24 (dppm) 3 (C 6 H 11 S) 17 ] 2 + was an oblate system.T he cluster contains an open icosahedralA u 1 Ag 12 core surrounded by the Ag 12 (dppm) 3 (SR) 15 shell and two thiol ligands.T he ring of Ag 12 (dppm) 3 (SR) 15 can be divided into three Ag 2 SR 5 andt hree Ag 2 (dppm). For the oblate total structure, the oblate shell resultsi nt he oblate shape.…”

“…Also, these types of nanoclusters are considered to be ideal models to investigate structure‐property correlations . As one type of metal nanoclusters, metal superatomic clusters present electronic structures similar withone certain atom from the periodic table, and the electronic characteristic can be maintained during assembly with other atoms and/or clusters . The Jellium metallic model was applied to describe the electronic structures of metal superatomic clusters, in which the free valence electron state of the cluster as a whole was similar to those of the corresponding atoms (Figure ) …”

“…[7][8][9][10][11][12] As one type of metal nanoclusters, metal superatomic clusters presente lectronic structures similar withone certaina tom from the periodic table, and the electronic characteristic can be maintained during assembly with other atoms and/or clusters. [13][14][15][16] The Jellium metallic model was appliedt od escribe the electronic structures of metal superatomic clusters, [17][18][19] in which the free valence electron state of the cluster as aw hole was similart o those of the corresponding atoms ( Figure 1). [16] The icosahedral M 13 unit (M = Au, Ag, Al etc.…”

Elucidating the Doping Effect on the Electronic Structure of Thiolate‐Protected Silver Superatoms by Photoelectron Spectroscopy

“…[5] TheA g 13 and Ag 32 cores form the closed-shell electronic configurations (1S) 2 (1P) 6 and (1S) 2 -(1P) 6 (1D) 10 ,r espectively:1 S, 1P,a nd 1D represent superatomic orbitals with angular momenta of 0, 1, and 2, respectively. [7][8][9] Thiolate-protected Ag clusters have attracted researchers due to specific properties such as photoluminescence [10] although they are generally less stable than the gold analogues.Doping with heteroatoms is apromising approach to enhance the stability and further improve the properties of the Ag clusters.S tate-of-the-art synthesis based on coreduction [11,12] and galvanic replacement [13,14] allowed us to precisely define the number, element, and location of the heteroatom(s) introduced into the Ag clusters.F or example, as ingle Ma tom (M = Au,P d, Pt) can be integrated exclusively at the central position of an icosahedral Ag 13 core of [Ag 25 (SPhMe 2 ) 18 ] À[1] to form M@Ag 12 cores in [AuAg 24 (SPhMe 2 ) 18 ] À[13] and [MAg 24 (SPhCl 2 ) 18 ] 2À (M = Pd, Pt) [11] (Scheme 1). [7][8][9] Thiolate-protected Ag clusters have attracted researchers due to specific properties such as photoluminescence [10] although they are generally less stable than the gold analogues.Doping with heteroatoms is apromising approach to enhance the stability and further improve the properties of the Ag clusters.S tate-of-the-art synthesis based on coreduction [11,12] and galvanic replacement [13,14] allowed us to precisely define the number, element, and location of the heteroatom(s) introduced into the Ag clusters.F or example, as ingle Ma tom (M = Au,P d, Pt) can be integrated exclusively at the central position of an icosahedral Ag 13 core of [Ag 25 (SPhMe 2 ) 18 ] À[1] to form M@Ag 12 cores in [AuAg 24 (SPhMe 2 ) 18 ] À[13] and [MAg 24 (SPhCl 2 ) 18 ] 2À (M = Pd, Pt) [11] (Scheme 1).…”

Optical properties of nanoalloys

“…Section 2 is then dedicated to a brief survey of this topic. Moreover, a sub-field evolving in a particularly tumultuous fashion among alloy nanosystems is that of monolayer-protected, size-selected clusters [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] . For clarity of presentation, we then single out these latter systems apart, so that in Section 3 we discuss other nanosystems, i.e., nanoclusters and nanorods or nanowires both free and in a less interacting environment, while Section 4 will be devoted to monolayer-protected alloy clusters, also providing a literature review of the explosive growth in this sub-field.…”