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Monolayer protected metal clusters comprise a rich class of molecular systems and are promising candidate materials for a variety of applications. While a growing number of protected nanoclusters have been synthesized and characterized in crystalline forms, their dynamical behavior in solution, including prenucleation cluster formation, is not well understood due to limitations both in characterization and first-principles modeling techniques. Recent advancements in machine-learned interatomic potentials are rapidly enabling the study of complex interactions such as dynamical behavior and reactivity on the nanoscale. Here, we develop an Au-S-C-H atomic cluster expansion (ACE) interatomic potential for efficient and accurate molecular dynamics simulations of thiolate-protected gold nanoclusters (Aun(SCH3)m). Trained on more than 30,000 density functional theory calculations of gold nanoclusters, the interatomic potential exhibits ab initio level accuracy in energies and forces and replicates nanocluster dynamics including thermal vibration and chiral inversion. Long dynamics simulations (up to 0.1 μs time scale) reveal a mechanism explaining the thermal instability of neutral Au25(SR)18 clusters. Specifically, we observe multiple stages of isomerization of the Au25(SR)18 cluster, including a chiral isomer. Additionally, we simulate coalescence of two Au25(SR)18 clusters and observe series of clusters where the formation mechanisms are critically mediated by ligand exchange in the form of [Au-S]n rings.

Fluorescent molecules have enabled single-molecule detection of toxins, biomarkers, and pollutants under controlled conditions. Unfortunately, these fluorophores are typically organic molecules that degrade or become photobleached when applied to non-ideal systems. Noble metal nanoclusters, in particular gold nanoclusters (AuNCs), pose a solution to the problems of degradation and photobleaching. Despite the low fluorescence quantum yield of AuNCs without thiolated ligands, labeling these clusters with fluorescent ligands allows enhancement of the fluorescence intensity and manipulation of the emission wavelength. In this work, we explore the labeling of the bi-icosahedron Au25 (bi-Au25) nanocluster. The bi-Au25 nanocluster has unique stability and electrochemical properties making it an attractive, yet poorly studied, candidate for fluorescent labeling. In order to demonstrate its potential as a near-IR emitting nanocluster we synthesized and labeled the bi-Au25 with the novel fluorophore 6-(9-Anthryl)-5-hexyne-1-thiol, or simply anthracenethiol. Two common ligands used in the synthesis of bi-Au25 are hexanethiol and phenylethanethiol, and we spectroscopically verify the ability for the straight-chain alkane hexanethiol to block the labeling of bi-Au25, while the aromatic phenylethanethiol enables the labeling of the complex. These products are characterized with square wave voltammetry, UV-vis and fluorescence spectrophotometry, and NMR spectrometry. The fluorescently labeled bi-Au25 nanocluster demonstrates a 25x increase in NIR photoluminescence at ~ 810 nm when originally capped with phenylethanethiol, and not the long-chain alkanethiol. The quantum yield of this cluster has been improved from 0.0786% in the unlabeled cluster to 1.97% in the labeled product. [ABSTRACT FROM AUTHOR]

High‐efficiency and low‐cost catalysts for oxygen evolution reaction (OER) are critical for electrochemical water splitting to generate hydrogen, which is a clean fuel for sustainable energy conversion and storage. Among the emerging OER catalysts, transition metal dichalcogenides have exhibited superior activity compared to commercial standards such as RuO2, but inferior stability due to uncontrolled restructuring with OER. In this study, we create bimetallic sulfide catalysts by adapting the atomic ratio of Ni and Co in CoxNi1‐xSy electrocatalysts to investigate the intricate restructuring processes. Surface‐sensitive X‐ray photoelectron spectroscopy and bulk‐sensitive X‐ray absorption spectroscopy confirmed the favorable restructuring of transition metal sulfide material following OER processes. Our results indicate that a small amount of Ni substitution can reshape the Co local electronic structure, which regulates the restructuring process to optimize the balance between OER activity and stability. This work represents a significant advancement in the development of efficient and noble metal‐free OER electrocatalysts through a doping‐regulated restructuring approach. [ABSTRACT FROM AUTHOR]

We report an anomalous structural transformation of a Cu(I) cluster into two different types of copper‐silver (CuAg) alloy nanoclusters. Different from previous reports, we demonstrate that under specifically designed reaction conditions, the Ag‐doping could induce a substantial growth of the starting Cu15 and a Ag13Cu20 nanocluster was obtained via the unexpected insertion of an Ag13 kernel inside the Cu(I)‐S shell. Ag13Cu20 demonstrates high activity to initiate the photopolymerization of previously hard‐to‐print inorganic polymers in 3D laser microprinting. Interestingly, a slight modification of the reaction condition leads to the formation of another Ag18‐xCuxS (8≤x) nanocluster templated by a central S2− anion, which possesses a unique electronic structure compared to conventional template‐free CuAg nanoclusters. Overall, this work unveils the intriguing doping chemistry of Cu clusters, as well as their capability to create different types of alloy nanoclusters with previously unobtainable structures and multifunctionality. [ABSTRACT FROM AUTHOR]

One of the ways to create plasmonic nanoparticles is through a physical method of synthesizing by thermal evaporation in a vacuum, which was chosen for analysis through computer simulation. Experimental data on the initial and annealed silver nanoparticles obtained in this manner were studied. It was found that small Ag nanoparticles (D < 3.5 nm) exhibited nearly ideal FCC structure, while larger nanoparticles unexpectedly showed predominantly icosahedral or decahedral modifications. To assess the mechanisms behind these experimental results, a study on the stability of Ag nanocluster structures with diameters D = 2.0–10.0 nm was conducted using molecular dynamics. Based on computer analysis of synthesis processes, subsequent cooling of Ag nanoparticles, and their thermal annealing, it was demonstrated that the theoretical discrepancy in the structure of experimentally obtained nanoparticles could only be explained by significant deformation of small Ag nanoparticles occurring during their deposition on a substrate in a liquid state. Possible ways to control the structure of Ag nanoparticles were identified. The regularities identified through computer simulation can be utilized in the preparation of Ag nanoparticles using physical synthesis methods. [ABSTRACT FROM AUTHOR]

Following exocytosis, the recapture of plasma membrane‐stranded vesicular proteins into recycling synaptic vesicles (SVs) is essential for sustaining neurotransmission. Surface clustering of vesicular proteins has been proposed to act as a 'pre‐assembly' mechanism for endocytosis that ensures high‐fidelity retrieval of SV cargo. Here, we used single‐molecule imaging to examine the nanoclustering of synaptotagmin‐1 (Syt1) and synaptic vesicle protein 2A (SV2A) in hippocampal neurons. Syt1 forms surface nanoclusters through the interaction of its C2B domain with SV2A, which are sensitive to mutations in this domain (Syt1K326A/K328A) and SV2A knockdown. SV2A co‐clustering with Syt1 is reduced by blocking SV2A's cognate interaction with Syt1 (SV2AT84A). Surprisingly, impairing SV2A‐Syt1 nanoclustering enhanced the plasma membrane recruitment of key endocytic protein dynamin‐1, causing accelerated Syt1 endocytosis, altered intracellular sorting and decreased trafficking of Syt1 to Rab5‐positive endocytic compartments. Therefore, SV2A and Syt1 are segregated from the endocytic machinery in surface nanoclusters, limiting dynamin recruitment and negatively regulating Syt1 entry into recycling SVs. [ABSTRACT FROM AUTHOR]

The purpose of current study was to assess the impact of ALA-coated gold nanoclusters (Au NPs) on the combined therapeutic effects of radiotherapy (RT) and photodynamic therapy (PDT) on healthy MCF-10A and MCF-7 breast cancer cells. The Au NPs were covered with ALA using PEG polymer, resulting in the synthesis of Au@ALA NPs. The successful synthesis of the final NPs was confirmed through FTIR, XRD, TEM, and UV–Vis tests. MCF-10A and MCF-7 cell lines were treated with different concentrations of Au@ALA NPs and exposed to irradiation of 2 and 4 Gy (using MV X-ray) and 630 nm laser light irradiation. Cytotoxicity was assessed using a multifaceted approach involving the MTT assay, real-time PCR, and colony forming assay. The findings revealed that the damage inflicted by Au@ALA NPs on cancerous tissue was significantly greater than that on normal tissue. The cytotoxic effects of all experimental groups exhibited a direct correlation with increasing concentrations and radiation doses. The combination of Au@ALA NPs with RT doses of 2 and 4 Gy resulted in a reduction in cell viability by a factor of 1.58 (P = 0.001) and 1.73 (P = 0.004), respectively. Furthermore, the simultaneous intervention of NPs with PDT and RT at doses of 2 and 4 Gy led to a decrease in cell viability by a factor of 2.10 (P = 0.001) and 3.08 (P = 0.001) in turn. Furthermore, the real-time PCR and colonogenic assay results demonstrated that the combined treatment significantly increased phosphorylation of ATM and expression of TP53, indicating an adequate synergistic effect on breast cancer cells. The concurrent application of Au@ALA NPs in RT and PDT successfully enhanced the radiosensitization of breast cancer cells to megavoltage RT and PDT. [ABSTRACT FROM AUTHOR]

Transition metal phosphides (TMPs) are promising hydrogen evolution reaction (HER) electrocatalysts, but the unsatisfying activity and durability at industrial‐scale current densities hinder their application. Downsizing TMPs to nanoclusters can substantially enhance their activity; yet, the high surface free energy tends to initiate agglomeration thereby limiting their service life. Herein, a molecular engineering strategy to synthesize robust sulfur‐doped RuP2 (S‐RuP2) nanoclusters, which can continuously provide ampere‐level current densities of 1.0, 2.0, and 3.0 A cm−2 for at least 480 h with low overpotentials of 55.6 ± 1.0, 90.6 ± 1.2, and 122.8 ± 1.0 mV, respectively, is proposed. In particular, it exhibits a remarkable charge transfer amount (representing a long service life), outperforming all reported alkaline HER electrocatalysts. Remoulding the RuP2 architecture by sulfur atom can significantly lift the d‐band center of Ru and the p‐band center of P, therefore strengthening the adsorption of H2O, H, and OH to reduce the barriers of water dissociation and H migration. The authors‘ research unveils the enormous potential of molecule‐based porous materials for designing high‐performance nano‐structured catalysts. [ABSTRACT FROM AUTHOR]

Quantum chemical modeling of CO oxidation on the Cu12S6(PH3)8 and Cu12S6 clusters was performed in order to establish the general tendencies in the process on metal nanoclusters stabilized by ligands and to find out if the presence of a phosphine ligand is needed in the active site. The Langmuir–Hinshelwood mechanism was studied, which involves sequential oxidation of two CO molecules with oxygen. The calculated activation energies on Cu12S6(PH3)8 are lower than on Cu12S6 for all oxidation stages; therefore, the PH3 ligands have a positive effect on the catalytic properties of the copper sulfide cluster in the CO oxidation. A linear correlation was found between the energy of CO adsorption on various copper sulfide clusters and the activation energy of the oxidation stage: the lowest activation energy is observed for the cluster with a CO adsorption energy of 36 kJ/mol. [ABSTRACT FROM AUTHOR]

The Förster Resonance Energy Transfer (FRET) is a widely used mechanism harnessed for sensing applications. For temporal stability of the energy transfer between donor and acceptor molecules their photostability and maintenance of the coupling geometry are important. A donor‐acceptor system was created from silicon nanoclusters (Si NCs) and silver nanoclusters (dihydrolopic acid (DHLA)‐protected Ag29 NCs). Optical spectroscopy and lifetime measurements helped to understand the energy transfer process between the Si NCs and Ag29 NCs. Compared with donor‐acceptor pairs based on gold nanocluster and organic dyes, the FRET pair formed between Si NCs and Ag29 (DHLA)12 NCs reaches a coequal efficiency of 60 %. A fine‐tuning of the system's parameters opens the door to investigating the sensitivity of the two nanocluster FRET system to various species and incorporating highly photostable moieties in a process relying on photoluminescence. [ABSTRACT FROM AUTHOR]

[Display omitted] • A Zr-based nanocluster molecular robot is applied for contaminated water remediation. • It exhibits a stimuli-responsive behavior with a molecular-level accuracy. • It shows 2 to 4 orders of magnitude faster anions removal rate than conventional sorbents. • Active sites responsible for anions capture are confirmed. • Cost analysis shows its economical applicability in practical application. Water contamination owing to anionic pollutants is a persisting and ubiquitous global threat. The current remediation technologies are mostly low in efficiency, expensive in materials and often associated with complicated processes. Herein, we report a characteristic zirconium-based nanocluster that can work as molecular robots for the efficient remediation of anions-contaminated water with great effectiveness and molecular-level accuracy. It exhibits a stimuli-responsive behavior to facilitate the water treatment process: dissolve in acidic aqueous solutions for molecular-level decontamination and quickly aggregate for post-remediation collection. It can precisely capture the representative anionic pollutants, whilst featuring satisfactory capacities (ca. 175 mg-arsenic/g, 60 mg-chromium/g, 45 mg-fluoride/g, 70 mg-phosphorus/g, respectively), super-fast kinetics (finishing uptake within seconds, which is two to four orders of magnitude faster than typical sorbents), as well as multi-cycle applications without appreciable loss of activity. The coexisting common ions show no effect on the target uptake. The responsible active site investigation shows that four active sites are responsible for the monovalent pollutant removal, and the active sites work in pairs to capture divalent chromate species. Cost analysis shows its economical applicability in practical applications. This work would lead to the development of effective water decontamination with higher effectiveness, more convenience, lower cost and more practical application value. [ABSTRACT FROM AUTHOR]

In the present work we have investigated the stability, CO poisoning tendency and HOR and ORR activities of small-sized monometallic Pt and bimetallic PtGe nanoclusters deposited on a series of 2D materials. By means of global minima search and mechanistic studies at the density functional theory (DFT) level with continuum implicit solvent, a screening of size, composition and support material has been carried out to obtain the optimal catalyst compositions that may boost the catalytic performance. Alloying and support effects work in two directions. On the one hand, the support increases the stability and modifies the electronic structure of the cluster via metal-support interaction. On the other hand, the cluster can change the electronic properties and catalytic activity of the support, which can be modulated with its size and composition. In addition, the 2D support assists pure Pt clusters in reducing the propensity to undergo CO poisoning, which can be further reduced by Ge alloying. This effect can be exploited to the point that the interaction with CO is not even favorable, as in Pt 5 Ge 5 /germanene, thus completely inhibiting the CO poisoning on the catalyst. Regarding the catalytic activities, all the catalysts studied in this work yield too high overpotentials for the ORR in acidic conditions, due to the presence of too oxophilic active sites which results in the overbinding of oxygenated species. However, the combination of Ge alloying and 2D support yield remarkable results in the HOR performance. The simultaneous tailoring of catalyst composition and support is demonstrated to be an effective strategy to successfully adjust the catalytic properties. [Display omitted] • This article studies the activity of Pt(Ge) clusters supported on 2D materials. • 2D materials enhance significantly the stability of monometallic clusters. • Combination of 2D material and Ge alloying drastically reduces CO poisoning. • Combination of 2D material and Ge alloying yields too oxophilic active sites for ORR. • Combination of 2D material and Ge alloying optimizes HOR performance. [ABSTRACT FROM AUTHOR]

Plasmon-induced hot-electron transfer from metal nanostructures is being intensely pursed in current photocatalytic research, however it remains elusive whether molecular-like metal clusters with excitonic behavior can be used as light-harvesting materials in solar energy utilization such as photocatalytic methanol steam reforming. In this work, we report an atomically precise Cu13 cluster protected by dual ligands of thiolate and phosphine that can be viewed as the assembly of one top Cu atom and three Cu4 tetrahedra. The Cu13H10(SR)3(PR’3)7 (SR = 2,4-dichlorobenzenethiol, PR’3 = P(4-FC6H4)3) cluster can give rise to highly efficient light-driven activity for methanol steam reforming toward H2 production.

The electrochemical CO2 reduction reaction (CO2RR) has been widely studied as a promising means to convert anthropogenic CO2 into valuable chemicals and fuels. In this process, the alkali metal ions present in the electrolyte are known to significantly influence the CO2RR activity and selectivity. In this study, we report a strategy for preparing efficient electrocatalysts by introducing a cation‐relaying ligand, namely 6‐mercaptohexanoic acid (MHA), into atom‐precise Au25 nanoclusters (NCs). The CO2RR activity of the synthesized Au25(MHA)18 NCs was compared with that of Au25(HT)18 NCs (HT=1‐hexanethiolate). While both NCs selectively produced CO over H2, the CO2‐to‐CO conversion activity of the Au25(MHA)18 NCs was significantly higher than that of the Au25(HT)18 NCs when the catholyte pH was higher than the pKa of MHA, demonstrating the cation‐relaying effect of the anionic terminal group. Mechanistic investigations into the CO2RR occurring on the Au25 NCs in the presence of different catholyte cations and concentrations revealed that the CO2‐to‐CO conversion activities of these Au25 NCs increased in the order Li+

In this article, we investigated the influence of molecular weight (Mw) on particle deposition efficiency after PEG-functionalized (polyethylene glycol-PEG) magnetoresponsive magnetic cluster targeting. In this work, the clusters were obtained by the solvothermal polyol method using polyethylene glycol (PEG) as a coating agent. So, we investigated three kinds of magnetoresponsive clusters: MNC-2000, MNC-6000, and MNC-10,000. These clusters were coated with PEG, and had molecular weights (Mw) of 2000 Da, 6000 Da, and 10,000 Da, respectively. The authors propose that the key to achieving maximum efficiency in targeted drug delivery is to deposit a thin, uniform layer of medication that covers the vascular wall in the area of interest. We defined a set of efficiency criteria to focus on the most essential characteristics of the targeting results. These are the obstruction degree, which measures the level of vessel obstruction; the magnet coverage degree, which evaluates the quality of particle deposition along the vessel wall; and the proximal deposition degree, which assesses the effect of pulsatile flow on deposition length. We performed several tests to determine how molecular weight affected these efficiency parameters. These tests examined (a) the effect of the injected cluster quantities, (b) the effect of the magnet distance, and (c) the effect of the injection period. Our findings indicate that an increase in PEG's molar weight significantly impacts magnetic particle targeting efficiency. [ABSTRACT FROM AUTHOR]

Nitrate reduction toward ammonia is pivotal in energy and environmental domains but faces challenges in achieving simultaneous high selectivity and activity. Manipulating interactions between intermediates and metal species is deemed effective for catalytic enhancement. In this study, a uniformly configured Fe1‐N4 single‐atom catalyst with four‐coordination was synthesized. Subsequent deposition of thiol‐poisoned Pd nanoclusters provided a platform to investigate the neighboring effect of Pd nanoclusters, excluding activity influences from Pd catalysts. Through this neighbor engineering, the Fe 3d electron spin configuration shifted from low spin to medium spin (MS). Experimental and theoretical analyses affirmed that MS Fe species optimized nitrate reduction by enhancing the *NO desorption process. This spin‐modulated Fe single‐atom catalyst demonstrated superior activity (392.16 mmol−1 gcat−1 h−1, ~40 mol−1 gFe−1 h−1) and a Faraday efficiency of 98.6% at −0.5 V vs. RHE, surpassing reported values. This study presents a promising strategy for nitrogen‐chemistry transition metal catalysts. [ABSTRACT FROM AUTHOR]

This study compares the properties of B12N12 and Si12C12 nanoclusters functionalized with tyrosine in the adsorption of organophosphorus pesticides, focusing on adsorption energy and electronic stability. The results indicate that B12N12/tyrosine exhibits more negative adsorption energies than Si12C12/tyrosine, suggesting stronger interactions and higher adsorption stability. Additionally, B12N12 demonstrates higher ionization energy and chemical hardness, enhancing its electronic stability during the adsorption process. In contrast, Si12C12 has higher electrophilicity and maximum electron transfer capacity, leading to greater variability in adsorption energy and more flexible electronic structure adjustments. These findings suggest that B12N12 nanoclusters have greater potential and application value as adsorption materials, particularly when modified with tyrosine. B12N12/tyrosine demonstrates higher stability and predictability in pesticide adsorption, making it more suitable for related applications. [ABSTRACT FROM AUTHOR]

Taking advantage of the metal–support interaction is an efficient strategy to rationally design cost-effective and highly efficient catalysts. Herein, we report that tiny Pt species anchored on nanoceria with N-rGO as support (denoted as Pt-CeO2/N-rGO) display size-dependent activity toward the hydrogen evolution reaction (HER). The PtSAPtNC-CeO2/N-rGO is far more active than PtSA-CeO2/N-rGO and PtSAPtNP-CeO2/N-rGO. The overpotential at 10 mA/cm2 is only 26 mV for PtSAPtNC-CeO2/N-rGO (5.0 wt %), ∼16 and 119 mV lower than that of commercial Pt/C (20.0 wt %) and a Pt catalyst supported on N-rGO with similar dispersion form (11.0 wt %), respectively. DFT calculations reveal that the electron interaction between Pt and CeO2 greatly favor water adsorption and reduce the H2 evolution energy barrier, which was further optimized by the synergistic effect between PtSA and PtNC. XPS measurement and charge density difference analysis indicate that electrons transfer from Pt single atoms to CeO2 and CeO2 reversely donate electrons to Pt nanoclusters. The electron-rich Pt nanoclusters enhance the electronic conductivity of the catalysts and thus accelerate the H2 evolution kinetics. Our work provides an idea of how to optimize catalytic performance via manipulating the metal–support interaction. [ABSTRACT FROM AUTHOR]

Fe–N–C catalysts are emerging as promising alternatives to Pt‐based catalysts for the oxygen reduction reaction (ORR), while they still suffer from sluggish reaction kinetics due to the discontented binding affinity between the Fe‐N4 sites and oxygen‐containing intermediates, and unsatisfactory stability. Herein, a flexible multichannel carbon fiber membrane immobilized with atomically dispersed Fe‐N4 sites and neighboring Fe nanoclusters/nanoparticles (FeN4‐FeNCP@MCF) is synthesized. The optimized geometric and electronic structures of the Fe atomic sites brought by adjacent Fe nanoclusters/nanoparticles and hierarchically porous structure of the carbon matrix endow FeN4‐FeNCP@MCF with outstanding ORR activity and stability, considerably outperforming its counterpart with FeN4 sites only and the commercial Pt/C catalyst. Liquid and solid‐state flexible zinc–air batteries employing FeN4‐FeNCP@MCF both exhibit outstanding durability. Theoretical calculation reveals that the Fe nanoclusters can trigger remarkable electron redistribution of the FeN4 sites and modulate the hybridization of central Fe 3d and O 2p orbitals, facilitating the activation of O2 molecules and optimizing the adsorption capacity of oxygen‐containing intermediates on FeN4 sites, and thus accelerating the ORR kinetic. This work offers an effective approach to constructing coupling catalysts that have single atoms coexisting with nanoclusters/nanoparticles for efficient ORR catalysis. [ABSTRACT FROM AUTHOR]

Owing to distinct physicochemical properties in comparison to gold and silver counterparts, atomically precise copper nanoclusters are attracting embryonic interest in material science. The introduction of copper cluster nanomaterials in more interesting fields is currently urgent and desired. Reported in this work are novel copper nanoclusters of [XCu54Cl12(tBuS)20(NO3)12] (X=S or none, tBuSH=2‐methyl‐2‐propanethiol), which exhibit high performance in photothermal conversion. The clusters have been prepared in one pot and characterized by combinatorial techniques including ultraviolet‐visible spectroscopy (UV‐vis), electrospray ionization mass spectrometry (ESI‐MS), and X‐ray photoelectron spectroscopy (XPS). The molecular structure of the clusters, as revealed by single crystal X‐ray diffraction analysis (SCXRD), shows the concentric three‐shell Russian doll arrangement of X@Cu14@Cl12@Cu40. Interestingly, the [SCu54Cl12(tBuS)20(NO3)12] cluster contains 8 free valence electrons in its structure, making it the first eight‐electron copper nanocluster stabilized by thiolates. More impressively, the clusters possess an effective photothermal conversion (temperature increases by 71 °C within ~50 s, λex=445 nm, 0.5 W cm−2) in a wide wavelength range (either blue or near‐infrared). The photothermal conversion can be even driven under irradiation of simulated sunlight (3 sun), endowing the clusters with great potency in solar energy utilization. [ABSTRACT FROM AUTHOR]

[Display omitted] As model catalysts, it is necessary to study the relationship between the structure and properties of ultra-small metal nanoclusters (MNCs) and to reduce their steric hindrance as much as possible, e.g. preparing ultrasmall MNCs protected by ultra-short ligands. However, it is challenging to attain various MNCs with the same cores but different surface stabilizing ligands. Additionally, shortening the chains of protecting ligands will lead to larger MNC cores. Here, four different Pd NCs (Pd 6 (SC 4 H 9) 12 , Pd 6 (SC 8 H 17) 12 , Pd 6 (SC 6 (C 2)H 17) 12 and Pd 6 (SC 6 H 13) 12) were successfully synthesized by a slow synthesis process. All these clusters consist of six Pd atoms and are stabilized by 12 thiols with different chain lengths and steric hindrance. The catalytic properties of the as-prepared Pd 6 NCs were evaluated using the catalytic reduction of p-nitroaniline to p-phenylenediamine as a model reaction. The outcomes indicated that shortening the chain length of the protecting thiols could enhance the catalytic activity of the Pd 6 NCs. Notably, stable and active ultra-small Pd 6 clusters stabilized by ultra-short ligands (HSC 4 H 9) were successfully synthesized. Although the performance of Pd 6 (SC 4 H 9) 12 clusters protected by the ultra-short thiols is lower than that of commercial palladium on carbon (Pd/C), they display higher stability. Interestingly, the activity of Pd 6 NCs protected by ethyl-branched alkane thiols is also better than that of Pd 6 NCs protected by the alkane thiol ligands with the same chain length or the same number of carbon numbers. This work provides clear evidence that the catalytic activity of atomically precise MNCs can be controlled by regulating the surface stabilizing ligands. [ABSTRACT FROM AUTHOR]

Atomically precise metal nanoclusters (NCs) have emerged as a new frontier in electrocatalysis, enabling the study of electrocatalytic reactions on well‐defined stable surfaces and rational electrocatalyst design based on atomic‐level tailoring. In this review, we focus on the recent applications of these NCs to energy conversion reactions, including those involved in water splitting (hydrogen and oxygen evolution reactions), fuel cell operation (oxygen reduction and hydrogen oxidation reactions), and electrochemical CO2 reduction. Emblematic examples are used to highlight the roles of different NC parts, for example, core metal and surrounding ligands, and the significance of the electrode substrate. Finally, we discuss the perspectives of the future development and implementation of NC‐based energy conversion systems. [ABSTRACT FROM AUTHOR]

The electrochemical carbon dioxide (CO2) reduction reaction (CRR, which can convert CO2 into useful compounds at room temperature and ambient pressure by using electricity derived from renewable energy source), has been attracting attention in recent years. This is because it can convert CO2 into useful compounds, which is pertinent to establishing a next‐generation recycling‐oriented energy society. However, further improvement of the electrocatalyst is required to improve its activity, selectivity, and durability. Among these, copper (Cu) can synthesize various hydrocarbons from CO2 and has been the most studied electrocatalyst for the CRR over many years. In particular, regarding ligand‐protected Cu particles for the CRR, the size, shape, and ligands of Cu particles prepared by chemical reduction can be precisely controlled. In this review, we summarize previous research on the size‐dependence of the CRR by using ligand‐protected Cu particles (nanoparticles and nanoclusters) prepared by liquid‐phase reduction, and discuss the current status of these studies for researchers on the electrochemical CRR. [ABSTRACT FROM AUTHOR]

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In this study, gold (Au), nanoclusters (NC) and heterogeneous titanium dioxide (TiO2) were successfully synthesized by low-temperature photoelectron spectroscopy. The chemical structure of Au-TiO2 was characterized by XRD, EDX, XPS and HR-TEM. Optical properties were evaluated using PL and UV–Vis, and electrical properties were evaluated using CV, CP, UPS and EIS parameters. The results showed that Au nanocluster (NCs) were converted into Au nanoparticles (NPs) during high sunlight, and the transfer mechanism was examined. In addition, the produced nanoparticles can form a Schottky barrier with TiO2, which affects the band structure. Moreover, the simultaneous synthesis of nanoparticles and nanoclusters adds an extra dimension to the understanding of the photoelectronic behavior of structured photoelectrodes. Moreover, this research shows that good control of the photography process can result in more photos. This improvement is related to several factors, including the plasmonic field and coupling line bending.

The equilibrium geometry and wave functions were calculated and a quantum topological study of electron density was performed for the supramolecular complexes [Ca(H2O)6]2+[(TiO2)n] (n = 1, 10‒16) and [Ca(H2O)6]2+[(TiO2)10(H2O)m] (m = 2, 8–10) with different numbers of water molecules in the hydration shell of the (TiO2)10 cluster using the density functional theory method in the B3LYP/6-31g(d, p) approximation. The binding of the calcium aqua ion with isolated (TiO2)n or hydrated (TiO2)10 mainly occurs due to the formation of OH···O intermolecular hydrogen bonds of the water molecules of the hydration shell of [Ca(H2O)6]2+ with the oxygen atoms of the titanium dioxide cluster. The energies of H bonds between the calcium aqua ion and the titanium dioxide nanocluster were calculated, and the bonds were shown to have high dynamic stability. [ABSTRACT FROM AUTHOR]

Regulating the metal‐support interaction of the anchored metal nanoclusters is recognized as valid approach to optimize the electrocatalytic performance through tuning the interfacial electronic structure. However, developing novel support and understanding the interfacial electron accumulation on modulating the reaction kinetics are still elusive. Herein, highly‐dispersed Ruthenium (Ru) nanoclusters anchored onto phosphorous doped molybdenum boride (Ru/P‐MoB) is developed through ultrafast microwave‐plasma (60 s) approach. The synthesized Ru/P‐MoB impressively promote the hydrogen evolution with low overpotentials of 34, 45, and 40 mV to drive 10 mA cm−2 in alkaline freshwater, alkaline seawater and acid media. Specially, it presents superior turnover frequency and mass/specific activity relative to Pt/C, Ru/C, and Ru/MoB. Moreover, the anion exchange membrane (AEM) electrolyzer cell based on Ru/P‐MoB can achieve 500 and 1000 mA cm−2 with small voltages of 1.71 and 1.78 V with good durability. Experimental and density functional theoretical (DFT) analysis reveal that the strong metal‐support interactions (Ru─Mo and Ru─P bonds) with generated interfacial electron‐enriched Ru, and then favoring the water‐molecule adsorption/dissociation and optimal H intermediate adsorption free energy. This work provides novel designing avenue to exploit electrocatalysts with outstanding catalytic performance under high current density at practical high‐temperature. [ABSTRACT FROM AUTHOR]

Luban locks with mortise and tenon structure have structural diversity and architectural stability, and it is extremely challenging to synthesize Luban lock‐like structures at the molecular level. In this work, we report the cocrystallization of two structurally related atom‐precise fcc silver nanoclusters Ag110(SPhF)48(PPh3)12 (Ag110) and Ag14(μ6‐S)(SPhF)12(PPh3)8 (Ag14). It is worth noting that the Ag110 cluster is the first compound to simulate the complex Luban lock structure at the molecular level. Meanwhile, Ag110 is the largest known fcc‐based silver nanocluster, so far, there is no precedent for fcc silver nanocluster with more than 100 silver atoms. DFT calculations show that Ag110 is a 58‐electron superatom with an electronically closed shell1S21P61D102S21F142P61G18. Ag110⋅Ag14 can rapidly catalyze the reduction of 4‐nitrophenol within 4 minutes. In addition, Ag110 presents clear structural evidence to reveal the critical size and mechanism of the transformation of metal core from fcc stacking to quasi‐spherical superatom. This research work provides an important structural model for studying the nucleation mechanism and structural assembly of silver nanoclusters. [ABSTRACT FROM AUTHOR]

Silver cluster‐based solids have garnered considerable attention owing to their tunable luminescence behavior. While surface modification has enabled the construction of stable silver clusters, controlling interactions among clusters at the molecular level has been challenging due to their tendency to aggregate. Judicious choice of stabilizing ligands becomes pivotal in crafting a desired assembly. However, detailed photophysical behavior as a function of their cluster packing remained unexplored. Here, we modulate the packing pattern of Ag12 clusters by varying the nitrogen‐based ligand. CAM‐1 formed through coordination of the tritopic linker molecule and NC‐1 with monodentate pyridine ligand; established via non‐covalent interactions. Both the assemblies show ligand‐to‐metal‐metal charge transfer (LMMCT) based cluster‐centered emission band(s). Temperature‐dependent photoluminescence spectra exhibit blue shifts at higher temperatures, which is attributed to the extent of the thermal reverse population of the S1 state from the closely spaced T1 state. The difference in the energy gap (ΔEST) dictated by their assemblies played a pivotal role in the way that Ag12 cluster assembly in CAM‐1 manifests a wider ΔEST and thus requires higher temperatures for reverse intersystem crossing (RISC) than assembly of NC‐1. Such assembly‐defined photoluminescence properties underscore the potential toolkit to design new cluster‐ assemblies with tailored optoelectronic properties. [ABSTRACT FROM AUTHOR]

Clinically, the immune checkpoint inhibitor anti-PD-1 antibody has shown a certain effect in the treatment of hepatocellular carcinoma (HCC), which is limited to a small number of patients with HCC. This study aims to reveal whether carnosic acid nanocluster-based framework (CA-NBF) has a sensitization effect on anti-PD-1 antibody in the treatment of HCC at the cellular and animal levels. MHCC97H cells were treated with CA-NBF, anti-PD-1 and their combination. The effects of CA-NBF and anti-PD-1 on cell proliferation, cell cycle, apoptosis, invasion, and migration were evaluated by MTT assay, flow cytometry, and scratch test. The effects of CA-NBF and anti-PD-1 on Wnt/β-catenin signaling pathway in MHCC97H cells were detected. A BALB/C nude mouse model of hepatocellular carcinoma was established, and the tumor growth was observed at different time points. The expression of cytotoxic T lymphocyte and helper T lymphocyte markers CD8 and CD4 in tumor tissues was detected by immunohistochemistry. Western blotting was used to detect the Wnt/β-catenin signaling pathway proteins (Wnt-3a, β-catenin, and GSK-3β) level in tumor tissues after CA-NBF and anti-PD-1 treatment. CA-NBF activity was significantly higher than CA, which could prominently reduce the proliferation, migration and invasion of MHCC97H cells and enhance apoptosis by inactivating Wnt/β-catenin signaling pathway. CA-NBF combined with anti-PD-1 antibody further enhanced cell proliferation, migration, invasion and pro-apoptosis but had no significant effect on Wnt/β-catenin signaling pathway. CA-NBF in vivo improved the tumor response to PD1 immune checkpoint blockade in HCC, manifested by reducing tumor size and weight, promoting CD4 and CD8 expression. CA-NBF combined with anti-PD-1 have stronger immunomodulatory and anticancer effects without increasing biological toxicity. [ABSTRACT FROM AUTHOR]

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Metal nanoclusters possess excellent electrochemical, optical, and catalytic properties, but correlating these properties remains challenging, which is the foundation to generate electrochemiluminescence (ECL). Herein, we report for the first time that a structurally determined Pt1Ag18 nanocluster generates intense ECL and simultaneously enhances the ECL of carbon dots (CDs) via an electrocatalytic effect. Pt1Ag18 nanocluster show aggregation‐induced emission enhancement and aggregation‐induced ECL enhancement under light and electrochemical stimulation, respectively. In the presence of tripropylamine (TPrA) as a coreactant, solid Pt1Ag18 shows unprecedented ECL efficiency, which is more than nine times higher than that of 1 mM Ru(bpy)32+ with the same TPrA concentration. Potential‐resolved ECL spectra reveal two ECL emission bands in the presence of TPrA. The ECL emission centered at 650 nm is assigned to the solid Pt1Ag18 nanocluster, consistent with the peak wavelength in self‐annihilation ECL and photoluminescence of the solid state. The ECL emission centered at 820 nm is assigned to the CDs on the glassy carbon electrode. The electrocatalytic effect of the nanoclusters enhanced the ECL of the CDs by a factor of more than 180 in comparison to that without nanoclusters. Based on the combined optical and electrochemical results, the ECL generation pathways and mechanisms of Pt1Ag18 and CDs are proposed. These findings are extremely promising for designing multifunctional nanocluster luminophores with strong emissions and developing ratiometric sensing devices. [ABSTRACT FROM AUTHOR]

The pursuit of highly emissive electrochemiluminescence (ECL) luminophores has long been a goal for both understanding mechanism and advancing detection applications. In this study, we employ ligand engineering to boost the ECL performance of bimetallic Au12Ag13 nanoclusters, substituting the PPh3 ligand with P(Ph‐OMe)3. The results demonstrate a 3.6‐fold enhancement in ECL efficiency following ligand exchange when compared to Au12Ag13‐PPh3, particularly in the presence of 1 mM tri‐n‐propylamine (TPrA) as a coreactant – surpassing the performance of the conventional Ru(bpy)32+ luminophore. Voltammetric analysis reveals the presence of both oxidative and reductive ECL signals under sweeping potentials, with corresponding ECL spectra collected. Proposed ECL mechanisms are rooted in the anodic and cathodic activities of Au12Ag13‐P(Ph‐OMe)3 nanoclusters. Notably, this work captures extremely high and transient ECL signals, sequentially activating LUMO and HOMO states, reminiscent of the behavior observed in Au12Ag13‐PPh3. Our findings present a promising strategy to enhance the ECL of metal nanoclusters, holding potential for further applications in sensing and detection. [ABSTRACT FROM AUTHOR]

Pt/ZrP2O7 catalysts exhibiting high activity for catalytic NOx reduction by H2 in the presence of excess O2 were developed in this study. At a low temperature of 125 °C and a high space velocity of approximately 5 × 104 h–1, 0.4 wt % Pt/ZrP2O7 facilitated a higher NO conversion to N2 (51%) than 0.4 wt % Pt/ZrO2 (<5%) for a reaction mixture of 200 ppm NO, 5000 ppm H2, 10% O2, and He balance. However, N2O and NO2 production increased at temperatures lower than 100 °C and higher than 200 °C, thereby decreasing the N2 yield. High-resolution electron microscopy and X-ray photoelectron spectroscopy analyses of 0.4 wt % Pt/ZrP2O7 revealed the coexistence of large metallic Pt crystallites with sizes of ∼20 nm and highly dispersed Pt oxide nanoclusters. When Pt loading was decreased to 0.05 wt %, the large metallic Pt crystallites disappeared, and only the Pt oxide nanoclusters remained on ZrP2O7. Owing to this structural change, N2O/NO2 formation was significantly suppressed, enabling highly selective NO reduction to N2. Moreover, catalyst preparation by equilibrium adsorption instead of wet impregnation further improved the reaction, achieving >90% selective NO conversion to N2, which was nearly free of undesired byproducts (NH3, N2O, and NO2) at 175 °C. The Pt oxide nanocluster supported on ZrP2O7 was more tolerant to the presence of 10% water vapor in the exhaust gas than the metallic Pt particles. Therefore, the developed catalyst is suitable for applications in practical exhaust gas purification for H2-fueled internal combustion engines. [ABSTRACT FROM AUTHOR]

Zirconium nitride (ZrN) is an industrial material having very high melting point, hardness and chemical stability. Compared to the bulk ZrN, its nanoclusters (NCs) are rarely explored. In this report, we generate a few ZrN NCs using ab initio molecular dynamics simulation. We investigate their electronic properties in terms of Bader charge, electron localization function and density of states. The obtained results are compared with their bulk counterpart. We also study the static and dynamical stability of the NCs with the help of binding energy, density of states and phonon dispersion spectra. The electron localization function of bulk ZrN is reported here for the first time to better understand its often confusing bonding behaviour. [ABSTRACT FROM AUTHOR]

Atomically precise Au nanoclusters (NCs) with discrete energy levels can be used as photosensitizers for CO2 reduction. However, tight ligand capping of Au NCs hinders CO2 adsorption on its active sites. Here, a new hybrid material is obtained by anchoring of thiol functionalized terpyridine metal complexes (metal=Ru, Ni, Fe, Co) on Au NCs by ligand exchange reactions (LERs). The anchoring of Ru and Ni complexes on Au25 NC (Au25−Ru and Au25−Ni) leads to adequate CO2 to CO conversion for photocoupled electrocatalytic CO2 reduction (PECR) in terms of high selectivity, with Faradaic efficiency of CO (FECO) exceeding 90 % in a wide potential range, remarkable activity (CO production rate up to two times higher than that for pristine Au25PET18) and extremely large turnover frequencies (TOFs, 63012 h−1 at −0.97 V for Au25−Ru and 69989 h−1 at −1.07 V vs. RHE for Au25−Ni). Moreover, PECR stability test indicates the excellent long‐term stability of the modified NCs in contrast with pristine Au NCs. The present approach offers a novel strategy to enhance PECR activity and selectivity, as well as to improve the stability of Au NCs under light illumination, which paves the way for highly active and stable Au NCs catalysts. [ABSTRACT FROM AUTHOR]

Enhancing cross-protections against diverse influenza viruses is desired for influenza vaccinations. Neuraminidase (NA)-specific antibody responses have been found to independently correlate with a broader influenza protection spectrum. Here, we report a sequential immunization regimen that includes priming with NA protein followed by boosting with peptide nanoclusters, with which targeted enhancement of antibody responses in BALB/c mice to certain cross-protective B-cell epitopes of NA was achieved. The nanoclusters were fabricated via desolvation with absolute ethanol and were only composed of composite peptides. Unlike KLH conjugates, peptide nanoclusters would not induce influenza-unrelated immunity. We found that the incorporation of a hemagglutinin peptide of H2-d class II restriction into the composite peptides could be beneficial in enhancing the NA peptide-specific antibody response. Of note, boosters with N2 peptide nanoclusters induced stronger serum cross-reactivities to heterologous N2 and even heterosubtypic N7 and N9 than triple immunizations with the prototype recombinant tetrameric (rt) N2. The mouse challenge experiments with HK68 H3N2 also demonstrated the strong effectiveness of the peptide nanocluster boosters in conferring heterologous protection. [ABSTRACT FROM AUTHOR]

A distinctive feature of oxide dispersion-strengthened alloys and steels, which provides a significant increase in heat resistance in comparison with traditional materials, is a significant number of homogeneously distributed nanoscale inclusions (oxides and clusters). For detailed characterization of such materials, a set of techniques is used, such as transmission electron microscopy, atom probe tomography, as well as small-angle scattering of X-rays and neutrons. The latter techniques make it possible to analyze the largest volume of material, while maintaining the ability to detect various nanoscale features. Since ferritic-martensitic oxide dispersion-strengthened steels are ferromagnetic materials, magnetic scattering has to be taken into account in the processing of small-angle neutron scattering data. The nanostructure of ferritic-martensitic oxide dispersion-strengthened steels with different alloying systems (different content of Cr, V, W, Al, and Zr) is investigated by small-angle neutron scattering. A comparison of the results of the study of the nanostructure of steels (oxide particles and clusters) in the ferromagnetic state with and without magnetic scattering is carried out. It is shown that oxide particles have a significantly higher magnetic contrast in comparison with nanoscale clusters. At the same time, the most accurate hardness values can be obtained by taking into consideration of both oxide inclusions and clusters. [ABSTRACT FROM AUTHOR]

Tow-dimensional and 3-dimensional colloidal structures have been used to study surface-enhanced Raman scattering and localized surface plasmon resonance because of their regular stacking structures. However, freely controlling the number and size of the colloidal assemblies remains a challenge. In this study, we demonstrated the fabrication and mechanism of tiny nanoclusters using spontaneous evaporation-based nanofountain pens (NFPs). A micrometer-scale NFP nozzle was fabricated using a glass capillary. The gold nanoparticles (AuNPs) dispersed ink formed the pendant droplet at the NFP nozzle tip, where the AuNPs accumulated within the pendant droplet because of evaporation. The accumulated AuNPs were transferred onto the substrate via a stamp-like process to create nanoclusters. Using water evaporation analyzed by diffusion equations, we showed that reducing the AuNP accumulation to one hundred is possible. This precise adjustment enables fabrication until submicrometer-level nanoclusters. The fabrication method using NFPs can create 3D structures, and this operation is not significantly affected by the size or composition of the AuNPs. This could be expanded to metabolite-included nanocluster where metabolite can be located at the hot spot among AuNPs. Therefore, we expect that this will be utilized to create SERS signals and conduct disease diagnosis research using extremely small amounts of metabolites. [ABSTRACT FROM AUTHOR]

It is important and challenging to analyze nanocluster structure with atomic precision. Herein, α-hemolysin nanopore was used to identify nanoclusters at the single molecule level by providing two-dimensional (2D) dwell time–current blockage spectra and translocation event frequency which sensitively depended on their structures. Nanoclusters such as Anderson, Keggin, Dawson, and a few lacunary Dawson polyoxometalates with very similar structures, even with only a two-atom difference, could be discriminated. This nanopore device could simultaneously measure multiple nanoclusters in a mixture qualitatively and quantitatively. Furthermore, molecular dynamics (MD) simulations provided microscopic understandings of the nanocluster translocation dynamics and yielded 2D dwell time–current blockage spectra in close agreement with experiments. The nanopore platform provides a novel powerful tool for nanocluster characterization. [ABSTRACT FROM AUTHOR]

[Display omitted] The development of novel efficient, safe antimicrobial strategies is an urgent need, as the misuse of antibiotics has become a significant threat to human health. Therefore, we have loaded metal Ni with environmentally friendly carbon black as a substrate, with species varying from single atoms to nanoclusters and nanoparticles. The results obtained from the antimicrobial systems and the role of different types of metal species in the photosensitized antimicrobial reactions were compared to better understand the catalytic behavior of different metal entities (single atoms, nanoclusters, and nanoparticles). Furthermore, the antimicrobial mechanisms of these materials were described by physical and chemical characterization, biological experiments, and theoretical calculations. Such systematic studies provide new ideas and prospects for developing more efficient and environmentally friendly antimicrobial materials. [ABSTRACT FROM AUTHOR]

The structure of two high-chromium (~14–15 at % Cr) oxide dispersion-strengthened steels was characterized using atom-probe tomography and transmission electron microscopy. One of the steels was manufactured using the conventional technology for preparing oxide dispersion-strengthened steels, with mechanical alloying of the matrix steel and yttrium oxide Y2O3 powder. Another steel was produced by mechanically alloying an oxidized powder of matrix steel with the intermetallic compound Fe3Y. It was shown that the average size of oxide inclusions in the examined steels ranged from 5 to 6 nm, with a number density from 1 × 1022 to 4 × 1023 m–3. The average size of clusters varied from 2 to 3 nm, with a number density ranging from 1 × 1023 to 3.2 × 1023 m–3. These clusters were predominantly enriched in Y and O. Steel produced with the addition of Fe3Y exibited a high number density of clusters (~3 × 1023 m–3) and a lower number density of oxides (~1 × 1022 m–3) compared to steels manufactured conventionally. It was also demonstrated that the high chromium concentration in the materials increased its presence in the matrix, thereby enhancing the corrosion resistance of the steels. [ABSTRACT FROM AUTHOR]

Oxide dispersion-strengthened steels are among the most promising materials for Generation IV reactor installations and thermonuclear power generation due to their high heat resistance, which is achieved by a significant number of uniformly distributed oxide particles. These materials can withstand temperatures up to 700°C and mitigate radiation-induced swelling within 200 dpa. The enhanced properties of such steels significantly depend on the specifics of their nanostructure, namely, the size and spatial distribution of dispersive inclusions (oxide particles and clusters). In this study, small-angle neutron scattering is applied to characterize the nanostructure of oxide dispersion-strengthened steels. This method enables the analysis of a large volume of material while retaining the ability to detect features such as clusters with sizes in the range of a few nanometers. The investigated steels have different alloying systems, varying in their concentration of Cr, V, W, Al, and Zr. Small-angle neutron scattering enables determination of the characteristic sizes of nanoscale inclusions in oxide dispersion-strengthened steels and their number densities. The results of small-angle neutron scattering are compared to the findings of transmission electron microscopy and atom-probe tomography. [ABSTRACT FROM AUTHOR]

In this work, numerical experiments were carried out in the framework of the molecular dynamics method to study the impact interaction of metallic nanoclusters of different sizes with a metallic substrate in a wide range of velocities. Analysis of the data obtained showed that the crater volume remains proportional to the impact energy and inversely proportional to the dynamic strength of the material, with the line slope being independent of the cluster size and the cluster–substrate material. [ABSTRACT FROM AUTHOR]

Monolayer-protected noble metal clusters, also called nanoclusters, can be produced with the atomic precision and in large-scale quantity and are playing an increasingly important role in the field of nanoscience. To outline the origin and the perspectives of this new field, we overview the main results obtained on free metal clusters produced in gas phase including mainly electronic properties, the giant atom concept, the optical properties, briefly the role of the metal atom (alkali, divalent, noble metal) and finally the atomic structure of clusters. We also discuss the limitations of the free clusters. Then, we describe the field of monolayer-protected metal clusters, the main results, the new offered perspectives, the added complexity, and the role of the ligand beyond the superatom concept. [ABSTRACT FROM AUTHOR]

The optical properties of doped metal nanoclusters (NCs) have stimulated great research interests because of their applications in biosensing and photocatalysis. The photoluminescence and excited state dynamics of MAu24(SR)18 are complicated and the detailed mechanism has not been fully understood. Here, we investigate the exciton and vibrational dynamics of two doped NCs MAu24(SR)18 (M=Pd, Pt; SR stands for phenylethanethiolate) by ultrafast spectroscopy. In contrast to the parent Au25(SR)18 NCs, Pd and Pt doping significantly reduce the exciton lifetime by several orders of magnitude. We find that the ultrashort exciton lifetimes of PtAu24 (5 ps) and PdAu24 (30 ps) are ascribed to the ultrasmall energy gap (Eg=0.3 eV). In both two doped NCs, we observe significant coherent vibrations (2.4 THz) that arise from the metal core, which indicates these oscillations can survive regardless of the short exciton lifetime. Unravelling the effect of foreign atom doping on the exciton and vibrational dynamics of metal NCs will provide new insight into their optical properties and help designing these molecular-like nanostructures for specific applications. [ABSTRACT FROM AUTHOR]