Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Insights into the Synthesis Mechanism of Ag29 Nanoclusters.

ABSTRACT: The current understanding of the synthesis mechanisms of noble metal clusters is limited, in particular for Ag clusters. Here, we present a detailed investigation into the synthesis process of atomically monodisperse Ag29 clusters, prepared via reduction of AgNO3 in the presence of dithiolate ligands. Using optical spectroscopy, mass spectrometry, and X-ray spectroscopy, it was determined that the synthesis involves a rapid nucleation and growth to species with up to a few hundred Ag atoms. From these larger species, Ag29 clusters are formed and their concentration increases steadily over time. Oxygen plays an important role in the etching of large particles to Ag29. No other stable Ag cluster species are observed at any point during the synthesis.

SUBMITTER: van der Linden M

PROVIDER: S-EPMC6369667 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Insights into the Synthesis Mechanism of Ag29 Nanoclusters.

van der Linden Marte M van Bunningen Arnoldus J AJ Delgado-Jaime Mario U MU Detlefs Blanka B Glatzel Pieter P Longo Alessandro A de Groot Frank M F FMF

The journal of physical chemistry. C, Nanomaterials and interfaces 20181119 49

The current understanding of the synthesis mechanisms of noble metal clusters is limited, in particular for Ag clusters. Here, we present a detailed investigation into the synthesis process of atomically monodisperse Ag29 clusters, prepared via reduction of AgNO3 in the presence of dithiolate ligands. Using optical spectroscopy, mass spectrometry, and X-ray spectroscopy, it was determined that the synthesis involves a rapid nucleation and growth to species with up to a few ...[more]

PMID: 30774744

Similar Datasets

Enantioseparation and chiral induction in Ag29 nanoclusters with intrinsic chirality.

Project description:The optical activity of a metal nanocluster (NC) is induced either by an asymmetric arrangement of constituents or by a dissymmetric field of a chiral ligand layer. Herein, we unveil the origin of chirality in Ag29 NCs, which is attributed to the intrinsically chiral atomic arrangement. The X-ray crystal structure of a Ag29(BDT)12(TPP)4 NC (BDT: 1,3-benzenedithiol; TPP: triphenylphosphine) manifested the presence of intrinsic chirality in the outer shell capping the icosahedral achiral Ag13 core. The enantiomers of the Ag29(BDT)12(TPP)4 NC are separated by high-performance liquid chromatography (HPLC) using a chiral column for the first time, showing mirror-image circular dichroism (CD) spectra. The CD spectra are reproduced by time-dependent density functional theory (TDDFT) calculations based on enantiomeric Ag29 models with achiral 1,3-propanedithiolate ligands. The mechanism of chiral induction in the synthesis of Ag29(DHLA)12 (DHLA: α-dihydrolipoic acid) NCs with a chiral ligand system is further discussed with the aid of DFT calculations. The use of the enantiomeric DHLA ligand preferentially leads to a one-handed atomic arrangement which is more stable than the opposite one, inducing the enantiomeric excess in the population of intrinsically chiral Ag29 NCs with CD activity.

| S-EPMC8157427 | biostudies-literature

Pyridine dicarbanion-bonded Ag13 organometallic nanoclusters: synthesis and on-surface oxidative coupling reaction.

Project description:Highly reactive organometallic nanoclusters in situ generated in metal-catalyzed reactions are pivotal in the comprehension of catalytic mechanisms. Herein, we develop a two-step synthetic method to achieve three unprecedented aryl dicarbanion-bonded Ag13 nanoclusters by using protective macrocyclic ligands. Firstly, various aryl dicarbanion-Ag4 cluster intermediates are acquired via a silver-mediated annulation reaction within a macrocyclic ligand. These Ag4 cluster precursors are released from the surrounding macrocycle by protonation, and further undergo an inter-cluster coupling to generate bipyridine products and low-valence silver atoms. The remaining resurgent diide-Ag4 clusters assemble with low-valence silver atoms to yield a series of organometallic Ag13 nanoclusters. These Ag13 nanoclusters feature a unique open-shell electronic structure as well as a chiral cluster architecture due to the asymmetric arrangements of surrounding aryl dianion ligands. Furthermore, the pyridyl diide ligands on the surface of the nanocluster further experience an intra-cluster oxidative coupling to produce bipyridine coupling products and large nanoparticles. The coupling reaction-driven cluster-to-cluster transformation is comprehensively tracked by high resolution mass spectroscopy. This work is not only reminiscent of the detailed evolution of cluster species upon the occurrence of coupling reactions, but also reproduces novel inter- and intra-cluster coupling steps at different reaction stages.

| S-EPMC9278448 | biostudies-literature

Spontaneous Resolution of Chiral Multi-Thiolate-Protected Ag30 Nanoclusters.

Project description:Despite significant progress achieved in the preparation of chiral nanoparticles, the enantioseparation of racemates still presents a big challenge in nanomaterial research. Herein, we report the synthesis and structural characterization of racemic anisotropic nanocluster Ag30(C2B10H9S3)8Dppm6 (Ag 30 -rac), which is protected by mixed carboranetrithiolate and phosphine ligands. Spontaneous self-resolution of the racemates was realized through conglomerate crystallization in dimethylacetamide (DMAc). The homochiral nanoclusters in the racemic conglomerates adopt enantiomeric helical self-assemblies (R/L-Ag 30 ). Diverse noncovalent interactions as the driving force in directing superstructure packing were elucidated in detail. Furthermore, the nanoclusters show red luminescence in both solid and solution states, and the racemic conglomerates display a mirror-image CPL response. This work provides atom-precise helical nanoparticle superstructures that facilitate an in-depth understanding of the helical-assembly mechanism.

| S-EPMC7706080 | biostudies-literature

Interdependence between nanoclusters AuAg24 and Au2Ag41.

Project description:Whole series of nanoparticles have now been reported, but probing the competing or coexisting effects in their synthesis and growth remains challenging. Here, we report a bi-nanocluster system comprising two ultra-small, atomically precise nanoclusters, AuAg24(SR)18- and Au2Ag41(SR)26(Dppm)2+ (SR = cyclohexyl mercaptan, Dppm = bis(diphenylphosphino)-methane). The mechanism by which these two nanoclusters coexist is elucidated, and found to entail formation of the unstable AuAg24(SR)18-, followed by its partial conversion to Au2Ag41(SR)26(Dppm)2+ in the presence of di-phosphorus ligands, and an interdependent bi-nanocluster system is established, wherein the two oppositely charged nanoclusters protect each other from decomposition. AuAg24(SR)18 and Au2Ag41(SR)26(Dppm)2 are fully characterized by single crystal X-ray diffraction (SC-XRD) analysis - it is found that their co-crystallization results in single crystals comprising equimolar amounts of each. The findings highlight the interdependent relationship between two individual nanoclusters, which paves the way for new perspectives on nanocluster formation and stability.

| S-EPMC7858706 | biostudies-literature

Evolution from superatomic Au24Ag20 monomers into molecular-like Au43Ag38 dimeric nanoclusters.

Project description:Hierarchical assembly of nanoparticles has been attracting wide interest, as advanced functionalities can be achieved. However, the ability to manipulate structural evolution of artificial nanoparticles into assemblies with atomic precision has been largely unsuccessful. Here we report the evolution from monomeric Au24Au20 into dimeric Au43Ag38 nanoclusters: Au43Ag38 inherits the kernel frameworks from parent Au24Ag20 but exhibits distinct surface motifs; Au24Ag20 is racemic, while Au43Ag38 is mesomeric. Importantly, the evolution from monomers to dimers opens up exciting opportunities exploring currently unknown properties of monomeric and dimeric alloy nanoclusters. The Au24Ag20 clusters show superatomic electronic configurations, while Au43Ag38 clusters have molecular-like characteristics. Furthermore, monomeric Au24Ag20 catalysts readily outperform dimeric Au43Ag38 catalysts in the catalytic reduction of CO2.

| S-EPMC8890245 | biostudies-literature

Bright near-infrared circularly polarized electrochemiluminescence from Au9Ag4 nanoclusters.

Project description:Metal nanoclusters are excellent electrochemiluminescent luminophores owing to their rich electrochemical and optical properties. However, the optical activity of their electrochemiluminescence (ECL) is unknown. Herein, we achieved, for the first time, the integration of optical activity and ECL, i.e., circularly polarized electrochemiluminescence (CPECL), in a pair of chiral Au9Ag4 metal nanocluster enantiomers. Chiral ligand induction and alloying were employed to endow the racemic nanoclusters with chirality and photoelectrochemical reactivity. S-Au9Ag4 and R-Au9Ag4 exhibited chirality and bright-red emission (quantum yield = 4.2%) in the ground and excited states. The enantiomers showed mirror-imaged CPECL signals at 805 nm owing to their highly intense and stable ECL emission in the presence of tripropylamine as a co-reactant. The ECL dissymmetry factor of the enantiomers at 805 nm was calculated to be ±3 × 10-3, which is comparable with that obtained from their photoluminescence. The obtained nanocluster CPECL platform shows the discrimination of chiral 2-chloropropionic acid. The integration of optical activity and ECL in metal nanoclusters provides the opportunity to achieve enantiomer discrimination and local chirality detection with high sensitivity and contrast.

| S-EPMC10321486 | biostudies-literature

Insights into the Synthesis Mechanisms of Ag-Cu3P-GaP Multicomponent Nanoparticles.

Project description:Metal-semiconductor nanoparticle heterostructures are exciting materials for photocatalytic applications. Phase and facet engineering are critical for designing highly efficient catalysts. Therefore, understanding processes occurring during the nanostructure synthesis is crucial to gain control over properties such as the surface and interface facets' orientations, morphology, and crystal structure. However, the characterization of nanostructures after the synthesis makes clarifying their formation mechanisms nontrivial and sometimes even impossible. In this study, we used an environmental transmission electron microscope with an integrated metal-organic chemical vapor deposition system to enlighten fundamental dynamic processes during the Ag-Cu3P-GaP nanoparticle synthesis using Ag-Cu3P seed particles. Our results reveal that the GaP phase nucleated at the Cu3P surface, and growth proceeded via a topotactic reaction involving counter-diffusion of Cu+ and Ga3+ cations. After the initial GaP growth steps, the Ag and Cu3P phases formed specific interfaces with the GaP growth front. GaP growth proceeded by a similar mechanism observed for the nucleation involving the diffusion of Cu atoms through/along the Ag phase toward other regions, followed by the redeposition of Cu3P at a specific Cu3P crystal facet, not in contact with the GaP phase. The Ag phase was essential for this process by acting as a medium enabling the efficient transport of Cu atoms away from and, simultaneously, Ga atoms toward the GaP-Cu3P interface. This study shows that enlightening fundamental processes is critical for progress in synthesizing phase- and facet-engineered multicomponent nanoparticles with tailored properties for specific applications, including catalysis.

| S-EPMC10134500 | biostudies-literature

Hydride-doped Ag17Cu10 nanoclusters as high-performance electrocatalysts for CO2 reduction.

Project description:The atomically precise metal electrocatalysts for driving CO2 reduction reactions are eagerly pursued as they are model systems to identify the active sites, understand the reaction mechanism, and further guide the exploration of efficient and practical metal nanocatalysts. Reported herein is a nanocluster-based electrocatalyst for CO2 reduction, which features a clear geometric and electronic structure, and more importantly excellent performance. The nanocatalysts with the molecular formula of [Ag17Cu10(dppm)4(PhC≡C)20H4]3+ have been obtained in a facile way. The unique metal framework of the cluster, with silver, copper, and hydride included, and dedicated surface structure, with strong (dppm) and labile (alkynyl) ligands coordinated, endow the cluster with excellent performance in electrochemical CO2 reduction reaction to CO. With the atomically precise electrocatalysts in hand, not only high reactivity and selectivity (Faradaic efficiency for CO up to 91.6%) but also long-term stability (24 h), are achieved.

| S-EPMC10518712 | biostudies-literature

Dual-quartet phosphorescent emission in the open-shell M1Ag13 (M = Pt, Pd) nanoclusters.

Project description:Dual emission (DE) in nanoclusters (NCs) is considerably significant in the research and application of ratiometric sensing, bioimaging, and novel optoelectronic devices. Exploring the DE mechanism in open-shell NCs with doublet or quartet emissions remains challenging because synthesizing open-shell NCs is difficult due to their inherent instability. Here, we synthesize two dual-emissive M1Ag13(PFBT)6(TPP)7 (M = Pt, Pd; PFBT = pentafluorobenzenethiol; TPP = triphenylphosphine) NCs with a 7-electron open-shell configuration to reveal the DE mechanism. Both NCs comprise a crown-like M1Ag11 kernel with Pt or Pd in the center surrounded by five PPh3 ligands and two Ag(SR)3(PPh3) motifs. The combined experimental and theoretical studies revealed the origin of DE in Pt1Ag13 and Pd1Ag13. Specifically, the high-energy visible emission and the low-energy near-infrared emission arise from two distinct quartet excited states: the core-shell charge transfer and core-based states, respectively. Moreover, PFBT ligands are found to play an important role in the existence of DE, as its low-lying π* levels result in energetically accessible core-shell transitions. This novel report on the dual-quartet phosphorescent emission in NCs with an open-shell electronic configuration advances insights into the origin of dual-emissive NCs and promotes their potential application in magnetoluminescence and novel optoelectronic devices.

| S-EPMC11252300 | biostudies-literature

Stability and its mechanism in Ag/CoOx/Ag interface-type resistive switching device.

Project description:Stability is an important issue for the application of resistive switching (RS) devices. In this work, the endurance and retention properties of Ag/CoOx/Ag interface-type RS device were investigated. This device exhibits rectifying I-V curve, multilevel storage states and retention decay behavior, which are all related to the Schottky barrier at the interface. The device can switch for thousands of cycles without endurance failure and shows narrow resistance distributions with relatively low fluctuation. However, both the high and low resistance states spontaneously decay to an intermediate resistance state during the retention test. This retention decay phenomenon is due to the short lifetime τ (τ = 0.5 s) of the metastable pinning effect caused by the interface states. The data analysis indicated that the pinning effect is dependent on the depth and density of the interface state energy levels, which determine the retention stability and the switching ratio, respectively. This suggests that an appropriate interface structure can improve the stability of the interface-type RS device.

| S-EPMC5069483 | biostudies-literature