Au137(SR)56nanomolecules: composition, optical spectroscopy, electrochemistry and electrocatalytic reduction of CO2

Jupally, Vijay Reddy; Dharmaratne, Asantha C.; Crasto, David; Huckaba, Aron J.; Kumara, Chanaka; Nimmala, Praneeth Reddy; Kothalawala, Nuwan; Delcamp, Jared H.; Dass, Amala

doi:10.1039/c4cc03424d

Cited by 57 publications

(70 citation statements)

References 34 publications

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“…[z] (blue), the major byproducts are in evidence, which can be identified as Au 137 (SR) 56 [z] (green) and Au 130 (SR) 50 [z] , by comparison to the prior literature. 30,32 (Upper Frame) This result is analogous to that shown in Figure S3, showing only the more robust Au 144 (SR) 60 [z] , but it is for the sample prior to the etching treatment. The Journal of Physical Chemistry C Article prefers to incorporate at the centered site, this being favored by at least 0.65 eV over the other sites.…”

Section: ■ Experimental Methodssupporting

confidence: 73%

“…In addition to the primary product, Au 144 (SR) 60 [z] , major byproducts are in evidence, which can be identified as Au 137 (SR) 56 [z] and Au 130 (SR) 50 [z] , by comparison to the prior literature. 30,31 The similar ESI MS result for pure Au 144 clusters, with overlay of the spectra at different charge states, is presented in Figure S3.…”

Section: ■ Experimental Methodsmentioning

confidence: 88%

“…The two peaks of greatest signal strength at m/z = 11820 and 11204 Da are consistent with the triply charged species of gold-rich clusters containing a single Cu atom, namely Au 144 Cu 1 (SR) 60 and Au 137 Cu 1 (SR) 56 , respectively. 30 A magnified spectrum is presented in the right frame of Figure 5. Figure 6 presents ESI-MS results for the Cu-free samples contacting Au 144 and Au 137 clusters, protected by peth ligands; these results show four sets of data points, corresponding to 1+, 2+, 3+ and 4+ charged states.…”

Section: ■ Experimental Methodsmentioning

confidence: 99%

“…Analysis by electrospray mass spectrometry reveals the dominant solution-phase species are monocopper derivatives of the known Au 144 (SR) 60 , i.e., CuAu 144 (SR) 60 , as well as a CuAu 137 (SR) 56 species, analogous to the recently found copper-free cluster. 30 Copper-free species contribute negligibly to the spectrum, but a small quantity of multiply substituted (Cu-for-Au) species is indicated. By contrast, in the report of Dharmaratne and Dass, 22 variable copper incorporation into the 144−145 atom Cu−Au clusters was found, depending on the starting ratio, up to perhaps 20 or 25 Cu atoms in total, but always as a broad, binomial-like distribution.…”

Section: ■ Concluding Remarksmentioning

confidence: 99%

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ESI-MS Identification of Abundant Copper–Gold Clusters Exhibiting High Plasmonic Character

Bhattarai¹,

Black²,

Boppidi³

et al. 2015

J. Phys. Chem. C

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The protected noble-metal structures comprising 145 metal-atom sites and 60 ligands are among the frequently identified larger metal-cluster systems exploited in many avenues of research. Herein we report a comparative electrospray ionizationmass spectrometry (ESI-MS) investigation of the 60-fold thiolated Au 144 and CuAu 144 clusters, in various positive charge-states, in conjunction with a density-functional theoretical (DFT) analysis based upon the icosahedral Pd 145 -structure-type applicable to these systems. Samples rich in the hexanethiolate-protected CuAu 144 clusters are obtained via a single-phase reduction process. The predicted electronic structure of the vacancy-centered Au 144 (SR) 60 system provided a simple rationale for the limiting [4+] charge-state observed of Au 144 , whereas the maximal [3+] charge detected on the CuAu 144 (SR) 60 cluster can be explained if the 145th atom occupies the central site. Occupancy of the center-site stabilizes the superatomic 3S-orbital, and thereby shifts the shell-closing count from 82 to 84 free electrons. The DFT-calculated energetics also predicts a strong (0.65 eV) preference for placing the smaller Cu ion in this central site. Remarkably, the optical absorption spectra of dilute tetrahydrofuran (THF) solutions feature a broad band centered near 2.3 eV, in contrast to the previously reported "nonplasmonic" response of sub-2.0-nm all-gold or -copper clusters. Other methods (matrix-assisted laser desorption ionization mass spectrometry and high-resolution electron microscopy) were used to investigate whether aggregation phenomena might account for this observed plasmon emergence. This unusual result points to the need to obtain highly purified samples of copper-doped gold clusters of ca. 145 atoms total. ■ INTRODUCTIONIn the physical chemistry of metal clusters, one prime concern has been to elucidate the rules, or criteria, that can explain the selection of exceptionally stable cluster sizes, or compositional "magic numbers", and predict the existence of other related special clusters. Typically, such special clusters are first identified by mass-spectrometric analysis, well before definitive structural characterization can be achieved. In the simpler ligand-free metal clusters, the main rules select for (i) the number of free electrons, n e , available to fill the set of angularmomentum shells, according to the universal aufbau of the spherical electron-shell model (or superatom analogy); and (ii) the number of metal atoms, n, required to complete concentric shells of atomic sites, as relating to crystallography and surface structure. 1,2 A simple metal cluster of formula A n[z] is said to be "doubly magic", if both counts, n and n e = v A n − z, satisfy the respective shell-closing criteria, where v A represents the metalatom valence and ze is the electrical charge. 3 Selected monolayer-protected clusters (MPCs), 4 denoted compositionally by A n X p [z] , feature an additional, external shell of p anionic ligand-groups, X − , that coordinate specifically t...

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Section: ■ Experimental Methodssupporting

confidence: 73%

Section: ■ Experimental Methodsmentioning

confidence: 88%

Section: ■ Experimental Methodsmentioning

confidence: 99%

Section: ■ Concluding Remarksmentioning

confidence: 99%

See 2 more Smart Citations

ESI-MS Identification of Abundant Copper–Gold Clusters Exhibiting High Plasmonic Character

Bhattarai¹,

Black²,

Boppidi³

et al. 2015

J. Phys. Chem. C

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“…The characterization of the theoretical structure of Au 67 (SR) 35 2− is also included for comparison. 30 From Figure 1 and Table 1, we find that the Iso1 has the same hollow m-Dh Au 17 inner core as Au 67 (SR) 35 2− , and Iso2 has a compact m-Dh Au 18 inner core, which has one more central atom than the hollow Au 17 inner core. With the increase of the number of atoms of the inner core, the symmetry becomes lower, such as Au 19 of Iso3 with C 2v and Au 20 of Iso4 with C 2 .…”

Section: ■ Introductionmentioning

confidence: 94%

Unraveling the Atomic Structures of the Au₆₈(SR)₃₄ Nanoparticles

Gao

2015

J. Phys. Chem. C

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The atomic structure prediction of thiolate-protected gold nanoparticle (RS-AuNP) Au 68 (SH) 34 is performed based on the "divide and protect" concept and experimental studies on 14 kDa RS-AuNPs. Four low-lying energy isomers, Iso1− Iso4, were identified by the density-functional theory. Our results indicate the most stable structure Iso2 adopts the C 2v Au 50 core with Marks-decahedral (m-Dh) Au 18 inner core. The calculated HOMO−LUMO gap is 0.74 eV, which is very close to that of Au 67 (SR) 35 2− . Further analysis suggests the 14 kDa RS-AuNPs might be not only the turn point between the fused core structure and the compact core structure but also the turn point between the one-shell inner core structure and the multishell inner core structure. The threshold number of Au atoms in bulk-like RS-AuNPs is evaluated as ∼263 based on the linear fitting of the HOMO−LUMO gaps of various RS-AuNPs including Au 68 (SR) 34 . The research on the medium-sized Au 68 (SR) 34 establishes a bridge between smaller and larger RS-AuNPs, which is beneficial for us to better understand the structures of the RS-AuNPs.

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Atomically Precise Metal Nanoclusters as Electrocatalysts

Sun¹,

Tang²,

Jiang³

2023

Atomically Precise Nanochemistry

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Au₁₃₇(SR)₅₆nanomolecules: composition, optical spectroscopy, electrochemistry and electrocatalytic reduction of CO₂

Cited by 57 publications

References 34 publications

ESI-MS Identification of Abundant Copper–Gold Clusters Exhibiting High Plasmonic Character

ESI-MS Identification of Abundant Copper–Gold Clusters Exhibiting High Plasmonic Character

Unraveling the Atomic Structures of the Au₆₈(SR)₃₄ Nanoparticles

Atomically Precise Metal Nanoclusters as Electrocatalysts

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Au137(SR)56nanomolecules: composition, optical spectroscopy, electrochemistry and electrocatalytic reduction of CO2

Cited by 57 publications

References 34 publications

ESI-MS Identification of Abundant Copper–Gold Clusters Exhibiting High Plasmonic Character

ESI-MS Identification of Abundant Copper–Gold Clusters Exhibiting High Plasmonic Character

Unraveling the Atomic Structures of the Au68(SR)34 Nanoparticles

Atomically Precise Metal Nanoclusters as Electrocatalysts

Contact Info

Product

Resources

About

Au₁₃₇(SR)₅₆nanomolecules: composition, optical spectroscopy, electrochemistry and electrocatalytic reduction of CO₂

Unraveling the Atomic Structures of the Au₆₈(SR)₃₄ Nanoparticles