Mass Spectrometry of Small Bimetal Monolayer-Protected Clusters

Fields-Zinna, Christina A.; Crowe, Matthew C.; Dass, Amala; Weaver, Joshua E. F.; Murray, Royce W.

doi:10.1021/la803865v

Cited by 192 publications

(250 citation statements)

References 35 publications

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“…Jin's group has demonstrated that Au 25 (SG) 18 acts as a chemoselective catalyst for oxidation of styrene and hydrogenation of ¡,¢-unsaturated ketones (or aldehydes) to unsaturated alcohols. 121,122 Recently, synthesis of 25-atom alloy clusters with well-defined compositions, such as Au 24 Pd(SC 2 H 4 Ph) 18 , 123 Au 24 Pd(SC n ) 18 , 124 Au 25¹n Ag n (SC n ) 18 , 125 has been reported by Murray's and Negishi's group. These clusters were selectively prepared by coreduction of the corresponding metal precursor ions followed by purification.…”

Section: ¹3mentioning

confidence: 99%

Toward an Atomic-Level Understanding of Size-Specific Properties of Protected and Stabilized Gold Clusters

Tsukuda

2012

Bulletin of the Chemical Society of Japan

232

230

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Metal clusters consisting of fewer than 100 atoms (diameter <2 nm) are highly promising as a new class of building units for functional materials because of their novel and size-dependent properties. Nevertheless, basic and applied studies of metals clusters have been hampered by the lack of specific guidelines for design and precise synthetic methods. This account surveys recent investigations of gold clusters focusing on our effort toward an atomic-level understanding and control of their size-specific properties. We have developed a size-controlled method for synthesizing gold clusters protected by ligands, stabilized by polymers, and supported on solids. Remarkable size-effects on stabilities and various properties including catalysis were observed. Their mechanisms are discussed based on fundamental knowledge of bare gold clusters in the gas phase.

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Section: ¹3mentioning

confidence: 99%

Toward an Atomic-Level Understanding of Size-Specific Properties of Protected and Stabilized Gold Clusters

Tsukuda

2012

Bulletin of the Chemical Society of Japan

232

230

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“…18 with a single Pd atom. 81 This report led to several theoretical studies of heteroatom doping of Au 25 (SR) 18 , 8284 which predicted that its doping with Pd would lead to the replacement of the central Au atom with a Pd atom and result in an increase in the thermodynamic stability of the cluster. Given this information, we investigated the effect of Pd doping on the stability of Au n (SR) m clusters to develop a method for creating metal clusters that are more stable than magic Au n (SR) m clusters.…”

Section: Determining Heteroatom Doping Effectsmentioning

confidence: 99%

“…While Au 25 (SR) 18 was only doped with a single Pd atom in the study by Murray et al, 81 the use of Ag and Cu as dopants, which belong to the same group as Au in the periodic table, was expected to lead to multiple heteroatom doping of Au 25 (SR) 18 . We therefore also investigated the effect of doping with Ag and Cu on the electronic structure of Au 25 (SR) 18 to develop a method for fine tuning magic Au n (SR) m cluster properties.…”

Section: Determining Heteroatom Doping Effectsmentioning

confidence: 99%

Toward the Creation of Functionalized Metal Nanoclusters and Highly Active Photocatalytic Materials Using Thiolate-Protected Magic Gold Clusters

Negishi

2013

Bulletin of the Chemical Society of Japan

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Advances in developments in nanotechnology have encouraged the creation of highly functionalized nanomaterials. Thiolate-protected gold clusters (Au n (SR) m ) less than 2 nm in size exhibit size-specific physical and chemical properties not observed in bulk metals. Therefore, they have attracted attention as functional units or building blocks in nanotechnology. The highly stable, magic Au n (SR) m clusters possess great potential as new nanomaterials. We are studying the following subjects related to magic Au n (SR) m clusters: (1) establishing methods to enhance their functionality, (2) developing high-resolution separation methods, and (3) utilizing the clusters as active sites in photocatalytic materials. Through these studies, we aim to create highly functional metal nanoclusters and apply them as highly active photocatalytic materials. The results of our efforts to date are summarized in this paper.

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“…Doping atomically precise nanoclusters is highly desired and allows atomic-level insight into the origin of fluorescence, which is of major importance. [46,47] Recently, several doped gold NCs with conserved core size have been successfully synthesized; [48][49][50][51][52][53] however, these thiolate-protected nanoclusters, as well as the phosphine-protected gold NCs, [13,16,54] are of low fluorescence. Herein, we report the discovery of drastic fluorescence enhancement in gold nanoclusters doped with 13 Ag atoms.…”

mentioning

confidence: 99%

A 200‐fold Quantum Yield Boost in the Photoluminescence of Silver‐Doped Ag_xAu_25−x Nanoclusters: The 13 th Silver Atom Matters

et al. 2014

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The rod-shaped Au 25 nanocluster possesses a low photoluminescence quantum yield (QY = 0.1 %) and hence is not of practical use in bioimaging and related applications. Herein, we show that substituting silver atoms for gold in the 25-atom matrix can drastically enhance the photoluminescence. The obtained Ag x Au 25Àx (x = 1-13) nanoclusters exhibit high quantum yield (QY = 40.1 %), which is in striking contrast with the normally weakly luminescent Ag x Au 25Àx species (x = 1-12, QY = 0.21 %). X-ray crystallography further determines the substitution sites of Ag atoms in the Ag x Au 25Àx cluster through partial occupancy analysis, which provides further insight into the mechanism of photoluminescence enhancement.Fluorescent nanomaterials are of major importance in many fields.[1-4] Different types of fluorescent nanomaterials have been developed, such as quantum dots (QDs), [5] lanthanide nanoparticles, [6,7] and carbon nanodots. [8,9] Metal nanoclusters (Ag, Au) have emerged as a new class of nanomaterial. [10][11][12][13][14][15][16][17][18][19][20][21][22][23] Compared to QDs, [24] Au and Ag nanoclusters (NCs) are more biocompatible and can be readily bioconjugated; other advantages include their extrememly small size, good photostability, and low toxicity; thus, fluorescent noble-metal NCs have been recognized as a promising candidate for cell labeling, biosensing, and photo-therapy applications. [25][26][27][28][29][30] However, a general issue lies in the lower quantum yield (QY) of metal NCs compared to QDs and organic dyes, which significantly limits the applications of metal NCs. Various approaches have been developed to synthesize noble metal NCs with enhanced fluorescence, for example: 1) engineering the particle surface by using different ligands, such as DHLA, [31] dendrimers, [32] polymers, [33] DNA, [34,35] peptides, and proteins; [36][37][38][39][40][41][42][43][44] 2) controlling the metal core size [45] or doping the core with other metal atoms. Doping atomically precise nanoclusters is highly desired and allows atomic-level insight into the origin of fluorescence, which is of major importance. [46,47] Recently, several doped gold NCs with conserved core size have been successfully synthesized; [48][49][50][51][52][53] however, these thiolate-protected nanoclusters, as well as the phosphine-protected gold NCs, [13,16,54] are of low fluorescence. Herein, we report the discovery of drastic fluorescence enhancement in gold nanoclusters doped with 13 Ag atoms. Interestingly, gold nanoclusters of the same structure, but doped with fewer Ag atoms, are only weakly fluorescent. Thus, the 13th Ag atom triggers strong fluorescence in the doped gold nanocluster.Two synthetic methods were devised for obtaining Agdoped, 25-metal-atom nanoclusters (see the Experimental Section and the Supporting Information for details). In the first route, polydisperse Au nanoparticles [16] were first made and then used as the precursors to react with an Ag I thiolate complex, which gave rise to Ag-doped gold nanocl...

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Mass Spectrometry of Small Bimetal Monolayer-Protected Clusters

Cited by 192 publications

References 35 publications

Toward an Atomic-Level Understanding of Size-Specific Properties of Protected and Stabilized Gold Clusters

Toward an Atomic-Level Understanding of Size-Specific Properties of Protected and Stabilized Gold Clusters

Toward the Creation of Functionalized Metal Nanoclusters and Highly Active Photocatalytic Materials Using Thiolate-Protected Magic Gold Clusters

A 200‐fold Quantum Yield Boost in the Photoluminescence of Silver‐Doped Ag_xAu_25−x Nanoclusters: The 13 th Silver Atom Matters

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Mass Spectrometry of Small Bimetal Monolayer-Protected Clusters

Cited by 192 publications

References 35 publications

Toward an Atomic-Level Understanding of Size-Specific Properties of Protected and Stabilized Gold Clusters

Toward an Atomic-Level Understanding of Size-Specific Properties of Protected and Stabilized Gold Clusters

Toward the Creation of Functionalized Metal Nanoclusters and Highly Active Photocatalytic Materials Using Thiolate-Protected Magic Gold Clusters

A 200‐fold Quantum Yield Boost in the Photoluminescence of Silver‐Doped AgxAu25−x Nanoclusters: The 13 th Silver Atom Matters

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A 200‐fold Quantum Yield Boost in the Photoluminescence of Silver‐Doped Ag_xAu_25−x Nanoclusters: The 13 th Silver Atom Matters