Coinage Metal Nanoclusters Research Articles

Advancements in Atomically Precise Nanocluster Protected by Thiacalix[4]arene.

Coinage metal nanoclusters (NCs), comprising a few to several hundred atoms, are prized for their size-dependent properties crucial in catalysis, sensing, and biomedicine. However, their practical application is often hindered by stability and reactivity challenges. Thiacalixarene, a macrocyclic ligand, shows promise in stabilizing silver, copper, and bimetallic NCs, enhancing their structural integrity and chemical stability. This investigation delves into the unique properties of thiacalix[4]arene and their role in bolstering NC stability, catalytic efficiency, and sensing capabilities. The current challenges and future prospects are critically evaluated, underscoring the transformative impact of thiacalix[4]arene in nanoscience. This review aims to broaden the utilization of atomically precise coinage metal NCs, unlocking new avenues across scientific and industrial applications.

Interactions of coinage metal nanoclusters with low-molecular-weight biocompounds.

Nowadays, coinage metal nanoclusters (NCs) are largely presented in diagnostics, bioimaging, and biocatalysis due to their high biocompatibility, chemical stability, and sensitivity to surrounding biomolecules. Silver and gold NCs are usually characterized by intense luminescence and photostability, which is in great demand in the detection of organic compounds, ions, pH, temperature, etc. The experimental synthesis of metal NCs often occurs on biopolymer templates, mostly DNA and proteins. However, this review mainly focuses on the interactions with small biomolecules (SBMs) of a molecular weight less than 1000 Da: amino acids, nucleobases, thiolates, oligopeptides, etc. Such molecules can serve as the templates for an eco-friendly facile one-pot synthesis of biocompatible luminescent NCs. The latter aspect makes NCs suitable for diagnostics and intracellular bioimaging. Another important aspect is the interaction of clusters with biomarkers, which is largely exploited by nanosensors: biomarker detection often occurs through either fluorescence emission "turn-on" or "turn-off" mechanisms. Moreover, as theoretical studies show, electronic absorption spectra and Raman spectra of the metal-organic complexes allow efficient detection of various analytes. In this regard, both theoretical and experimental studies of SBM complexes with metal NCs are in great demand. Therefore, this review aims to summarize up-to-date studies on the interaction of small biomolecules with coinage metal NCs from both theoretical and experimental viewpoints.

Silvery fullerene in Ag102 nanosaucer.

Despite the discovery of a series of fullerenes and a handful of noncarbon clusters with the typical topology of I h-C60, the smallest fullerene with a large degree of curvature, C20, and its other-element counterparts are difficult to isolate experimentally. In coinage metal nanoclusters (NCs), the first all-gold fullerene, Au32, was discovered after a long-lasting pursuit, but the isolation of similar silvery fullerene structures is still challenging. Herein, we report a flying saucer-shaped 102-nuclei silver NC (Ag102) with a silvery fullerene kernel of Ag32, which is embraced by a robust cyclic anionic passivation layer of (KPO4)10. This Ag32 kernel can be viewed as a non-centered icosahedron Ag12 encaged into a dodecahedron Ag20, forming the silvery fullerene of Ag12@Ag20. The anionic layer (KPO4)10 is located at the interlayer between the Ag32 kernel and Ag70 shell, passivating the Ag32 silvery fullerene and templating the Ag70 shell. The t BuPhS- and CF3COO- ligands on the silver shell show a regioselective arrangement with the 60 t BuPhS- ligands as expanders covering the upper and lower of the flying saucer and 10 CF3COO- as terminators neatly encircling the edges of the structure. In addition, Ag102 shows excellent photothermal conversion efficiency (η) from the visible to near-infrared region (η=67.1%±0.9% at 450nm, 60.9%±0.9% at 660nm and 50.2%±0.5% at 808nm), rendering it a promising material for photothermal converters and potential application in remote laser ignition. This work not only captures silver kernels with the topology of the smallest fullerene C20, but also provides a pathway for incorporating alkali metal (M) into coinage metal NCs via M-oxoanions.

Advances in coinage metal nanoclusters: From synthesis strategies to electrocatalytic performance

Advances in coinage metal nanoclusters: From synthesis strategies to electrocatalytic performance

Role of transition metals in coinage metal nanoclusters for the remediation of toxic dyes in aqueous systems.

A difficult issue in chemistry and materials science is to create metal compounds with well-defined components. Metal nanoclusters, particularly those of coinage groups (Cu, Ag, and Au), have received considerable research interest in recent years owing to the availability of atomic-level precision via joint experimental and theoretical methods, thus revealing the mechanisms in diverse nano-catalysts and functional materials. The textile sector significantly contributes to wastewater containing pollutants such as dyes and chemical substances. Textile and fabric manufacturing account for about 7 × 105 tons of wastewater annually. Approximately one thousand tons of dyes used in textile processing and finishing has been recorded as being discharged into natural streams and water bodies. Owing to the widespread environmental concerns, research has been conducted to develop absorbents that are capable of removing contaminants and heavy metals from water bodies using low-cost technology. Considering this idea, we reviewed coinage metal nanoclusters for azo and cationic dye degradation. Fluorometric and colorimetric techniques are used for dye degradation using coinage metal nanoclusters. Few reports are available on dye degradation using silver nanoclusters; and some of them are discussed in detailed herein to demonstrate the synergistic effect of gold and silver in dye degradation. Mostly, the Rhodamine B dye is degraded using coinage metals. Silver nanoclusters take less time for degradation than gold and copper nanoclusters. Mostly, H2O2 is used for degradation in gold nanoclusters. Still, all coinage metal nanoclusters have been used for the degradation due to suitable HOMO-LUMO gap, and the adsorption of a dye onto the surface of the catalyst results in the exchange of electrons and holes, which leads to the oxidation and reduction of the adsorbed dye molecule. Compared to other coinage metal nanoclusters, Ag/g-C3N4 nanoclusters displayed an excellent degradation rate constant with the dye Rhodamine B (0.0332 min-1). The behavior of doping transition metals in coinage metal nanoclusters is also reviewed herein. In addition, we discuss the mechanistic grounds for degradation, the fate of metal nanoclusters, anti-bacterial activity of nanoclusters, toxicity of dyes, and sensing of dyes.

Exceptional stability of ultrasmall cubic copper metal nanoclusters - a molecular dynamics study.

The fabrication of shape-selective coinage metal nanoclusters (MNCs) has promising applications due to their exceptional physical and chemical molecule-like properties. However, the stability of the specific geometry of the nanoclusters, such as their cubic shapes, is unclear and has been unraveled by assessing the nanoclusters' interactions with different environments. In this work, we investigate the morphological stability of cubic structured, coinage metal nanoclusters of varying sizes ranging from 14 to 1099 atoms. The impact of solvent environments like water and the presence of ionic liquids (IL) on the stabilization of the MNCs were assessed using molecular dynamics (MD) simulations. In general, smaller MNCs composed of less than 256 atoms encountered structural distortion easily compared to the larger ones, which preserved their cubic morphology with minimal surface aberrations in water. However, in the presence of 4M 1-butyl-1,1,1-trimethyl ammonium methane sulfonate [N1114][C1SO3] IL solution, the overall cubic shape of the MNCs was successfully preserved. Strikingly, it is observed that in contrast to the noble MNCs like Au and Ag, the cubic morphology for Cu MNCs with sizes less than 256 atoms exhibited significant stability even in the absence of IL.

Recent Advances in Long-Lived Emission in Coinage Metal Nanoclusters: Implications for Optoelectronic Applications

Recent Advances in Long-Lived Emission in Coinage Metal Nanoclusters: Implications for Optoelectronic Applications

Total Structure, Structural Transformation and Catalytic Hydrogenation of [Cu41 (SC6 H3 F2 )15 Cl3 (P(PhF)3 )6 (H)25 ]2- Constructed from Twisted Cu13 Units.

Herein, a remarkable achievement in the synthesis and characterization of an atomically precise copper-hydride nanocluster, [Cu41 (SC6 H3 F2 )15 Cl3 (P(PhF)3 )6 (H)25 ]2- via a mild one-pot reaction is presented. Through X-ray crystallography analysis, it is revealed that [Cu41 (SC6 H3 F2 )15 Cl3 (P(PhF)3 )6 (H)25 ]2- exhibits a unique shell-core-shell structure. The inner Cu29 kernel is composed of three twisted Cu13 units, connected through Cu4 face sharing. Surrounding the metal core, two Cu6 metal shells, resembling a protective sandwich structure are observed. This arrangement, along with intracluster π···π interactions and intercluster C─H···F─C interactions, contributes to the enhanced stability of [Cu41 (SC6 H3 F2 )15 Cl3 (P(PhF)3 )6 (H)25 ]2- . The presence, number, and location of hydrides within the nanocluster are established through a combination of experimental and density functional theory investigations. Notably, the addition of a phosphine ligand triggers a fascinating nanocluster-to-nanocluster transformation in [Cu41 (SC6 H3 F2 )15 Cl3 (P(PhF)3 )6 (H)25 ]2- , resulting in the generation of two nanoclusters, [Cu14 (SC6 H3 F2 )3 (PPh3 )8 H10 ]+ and [Cu13 (SC6 H3 F2 )3 (P(PhF)3 )7 H10 ]0 . Furthermore, it is demonstrated that [Cu41 (SC6 H3 F2 )15 Cl3 (P(PhF)3 )6 (H)25 ]2- exhibits catalytic activity in the hydrogenation of nitroarenes. This intriguing nanocluster provides a unique opportunity to explore the assembly of M13 units, similar to other coinage metal nanoclusters, and investigate the nanocluster-to-nanocluster transformation in phosphine and thiol ligand co-protected copper nanoclusters.

Unveiling the Long-Lived Emission of Copper Nanoclusters Embedded in a Protein Scaffold.

Protein-conjugated coinage metal nanoclusters have become promising materials for optoelectronics and biomedical applications. However, the origin of the photoluminescence, especially the long-lived excited state emission in these metal nanoclusters, is still elusive. Here, we unveiled the underlying mechanism of long-lived emission in albumin protein-conjugated copper nanoclusters (Cu NCs) using steady state and time-resolved spectroscopic techniques. Our findings reveal room-temperature phosphorescence (RTP) in protein-conjugated Cu NCs. Time-resolved area-normalized spectra distinguished short- and long-lived components, where the former arises from the singlet state and the latter from the triplet state, thus resulting in RTP. The similarity of the emission spectra at room (298 K) and cryogenic (77 K) temperature ascertains the RTP phenomenon by harvesting the higher-lying triplet states. Time-gated bioimaging of A549 cells using the long-lived emission not only supports RTP emission in the cellular environment but also provides exciting avenues in long-term bioimaging using bovine serum albumin-conjugated Cu NCs.

Ligand engineering of coinage metal nanoclusters: The synthesis and properties of calixarene stabilized nanoclusters

Ligand engineering of coinage metal nanoclusters: The synthesis and properties of calixarene stabilized nanoclusters

Up‐ and Down‐Shifting Nanomaterials with Chiroptical Responses: Origin of their Chiroptical Activity and Applications

AbstractArtificial chiral nanoparticles exhibit unique optical and (photo)physical properties. They can be all‐inorganic or organic–inorganic materials that are usually confined to the nanoscale by anchoring organic ligands to their surface. The ligands can also possess distinctive optical and/or (photo)physical properties, thereby adding functionality to the whole nanosystem and constituting an organic–inorganic nanohybrid. Development of luminescent chiral nanoparticles and nanohybrids is pertinent to many applications, such as (bio)sensing, therapeutics, photocatalysis, and optoelectronics, among others. This review deals with different photoactive nanomaterials, displaying either up‐shifting emission (nanoparticles consisting of a photoactive or inert matrix doped with lanthanides, Ln3+, upconversion nanoparticles, UCNPs) or down‐shifting emission, such as coinage metal nanoclusters (e.g., gold nanoclusters, AuNCs) and lead halide perovskite nanoparticles (HP NPs), as well as very low emissive nanoparticles, such as plasmonic nanoparticles (such as gold nanoparticles, AuNPs). Special attention is paid to the origin of the chiroptical response of these materials, showing that it is varied and can be alike for some of them.

Ultrasmall Coinage Metal Nanoclusters as Promising Theranostic Probes for Biomedical Applications.

Ultrasmall coinage metal nanoclusters (NCs, <3 nm) have emerged as a novel class of theranostic probes due to their atomically precise size and engineered physicochemical properties. The rapid advances in the design and applications of metal NC-based theranostic probes are made possible by the atomic-level engineering of metal NCs. This Perspective article examines (i) how the functions of metal NCs are engineered for theranostic applications, (ii) how a metal NC-based theranostic probe is designed and how its physicochemical properties affect the theranostic performance, and (iii) how metal NCs are used to diagnose and treat various diseases. We first summarize the tailored properties of metal NCs for theranostic applications in terms of biocompatibility and tumor targeting. We focus our discussion on the theranostic applications of metal NCs in bioimaging-directed disease diagnosis, photoinduced disease therapy, nanomedicine, drug delivery, and optical urinalysis. Lastly, an outlook on the challenges and opportunities in the future development of metal NCs for theranostic applications is provided.

All-alkynyl-protected coinage metal nanoclusters: from synthesis to electrocatalytic CO2reduction applications

Alkynyl-protected metal nanoclusters possess unique advantages, and the recent progress on the controllable synthesis and CO2electroreduction application is discussed, with some explicit examples to elaborate the structure-performance relationship.

Recent developments in the investigation of driving forces for transforming coinage metal nanoclusters.

Metal nanoclusters serve as an emerging class of modular nanomaterials. The transformation of metal nanoclusters has been fully reflected in their studies from every aspect, including the structural evolution analysis, physicochemical property regulation, and practical application promotion. In this review, we highlight the driving forces for transforming atomically precise metal nanoclusters and summarize the related transforming principles and fundamentals. Several driving forces for transforming nanoclusters are meticulously reviewed herein: ligand-exchange-induced transformations, metal-exchange-induced transformations, intercluster reactions, photochemical transformations, oxidation/reduction-induced transformations, and other factors (intrinsic instability, pH, temperature, and metal salts) triggering transformations. The exploitation of transforming principles to customize the preparations, structures, physicochemical properties, and practical applications of metal nanoclusters is also disclosed. At the end of this review, we provide our perspectives and highlight the challenges remaining for future research on the transformation of metal nanoclusters. Our intended audience is the broader scientific community interested in metal nanoclusters, and we believe that this review will provide researchers with a comprehensive synthetic toolbox and insights on the research fundamentals needed to realize more cluster-based nanomaterials with customized compositions, structures, and properties.

Surface modifications of eight-electron palladium silver superatomic alloys

Atomically precise thiolate-protected coinage metal nanoclusters and their alloys are far more numerous than their selenium congeners, the synthesis of which remains extremely challenging. Herein, we report the synthesis of a series of atomically defined dithiophosph(in)ate protected eight-electron superatomic palladium silver nanoalloys [PdAg20{S2PR2}12], 2a–c (where R = OiPr, a; OiBu, b; Ph, c) via ligand exchange and/or co-reduction methods. The ligand exchange reaction on [PdAg20{S2P(OnPr)2}12], 1, with [NH4{Se2PR2}12] (where R = OiPr, or OnPr) leads to the formation of [PdAg20{Se2P(OiPr)2}12] (3) and [PdAg20{Se2P(OnPr)2}12] (4), respectively. Solid state structures of 2a, 2b, 3 and 4 unravel different PdAg20 metal frameworks from their parent cluster, originating from the different distributions of the eight-capping silver(I) atoms around a Pd@Ag12 centered icosahedron with C2,D3,Th and Th symmetries, respectively. Surprisingly ambient temperature crystallization of the reaction product 3 obtained by the ligand exchange reaction on 1 has resulted in the co-crystallization of two isomers in the unit cell with overall T (3a) and C3 (3b) symmetries, respectively. To our knowledge, this is the first ever characterized isomeric pair among the selenolate-protected NCs. Density functional theory (DFT) studies further rationalize the preferred geometrical isomerism of the PdAg20 core.

Engineering Coinage Metal Nanoclusters for Electroluminescent Light-Emitting Diodes.

Coinage metal nanoclusters (MNCs) are a new type of ultra-small nanoparticles on the sub-nanometer (typically < three nm) scale intermediate between atoms and plasmonic nanoparticles. At the same time, the ultra-small size and discrete energy levels of MNCs enable them to exhibit molecular-like energy gaps, and the total structure involving the metal core and surface ligand together leads to their unique properties. As a novel environmentally friendly chromophore, MNCs are promising candidates for the construction of electroluminescent light-emitting diodes (LEDs). However, a systematic summary is urgently needed to correlate the properties of MNCs with their influences on electroluminescent LED applications, describe the synthetic strategies of highly luminescent MNCs for LEDs’ construction, and discuss the general influencing factors of MNC-based electroluminescent LEDs. In this review, we first discuss relevant photoemissions of MNCs that may have major influences on the performance of MNC-based electroluminescent LEDs, and then demonstrate the main synthetic strategies of highly luminescent MNCs. To this end, we illustrate the recent development of electroluminescent LEDs based on MNCs and present our perspectives on the opportunities and challenges, which may shed light on the design of MNC-based electroluminescent LEDs in the near future.

An Overview on Coinage Metal Nanocluster-Based Luminescent Biosensors via Etching Chemistry.

The findings from the synthetic mechanism of metal nanoclusters yield the etching chemistry based on coinage metal nanoclusters. The utilization of such chemistry as a tool that can alter the optical properties of metal nanoclusters has inspired the development of a series of emerging luminescent biosensors. Compared with other sensors, the luminescent biosensors have the advantages of being more sensitive, saving time and saving cost. We reviewed topics on the luminescent sensors based on the etching of emissive coinage metal nanoclusters. The molecules possessing varied etching ability towards metal nanoclusters were categorized with discussions of corresponding etching mechanisms. The understanding of etching mechanisms favored the discussions of how to use etching methods to detecting biochemical molecules. The emerging luminescent biosensors via etching chemistry also provided challenges and new opportunities for analytical chemistry and sensors.

Luminescent Sensors Based on the Assembly of Coinage Metal Nanoclusters

Coinage metals, such as Cu, Ag and Au, can form nanoclusters, which, when functionalized with ligands, have unique electronic and optical properties and are widely used in biomedical imaging, remote sensing, labeling, catalytic, etc. The mechanisms, structures and properties of nanocluster assemblies have been well reviewed. However, the collections and analyses of nanocluster assemblies for sensor application are few. This review examines different nanocluster sensor platforms with a focus on the assembly and analysis of the assembly processes and examples of applications.

Large-Sized Aun- Core-Shell Clusters (n = 61-66): Enduring Structure of the Icosahedral Au13 Core.

Large-sized gold Aun- anion clusters exhibit structural characteristics drastically different from other coinage metals. Typically, coinage metal nanoclusters exhibit a 13-atom icosahedral core at the cluster size of 55. Gold clusters, contrarily, do not entail this core until the size reaches 60. Here, we investigated the robustness of the icosahedral core within the large-sized Aun- anion clusters. We found that the icosahedral core persists over the size of range of n = 61-66. To adapt the exceptional robustness of the icosahedral core, the shells of the clusters tend to undergo notable structural deformations with polygonal defects. As the cluster size increases from 61 to 66, the core starts to become distorted at n = 64 and the space between the core and shell becomes enlarged. To our knowledge, this is the first theoretical study that provides the simulated photoelectron spectra of the two largest sized gold clusters: Au65- and Au66-.

Superatomic Orbital Splitting in Coinage Metal Nanoclusters.

The superatomic orbital splitting (SOS) method is developed to understand the electronic structures of coinage metal nanoclusters, in which delocalized electron counts are not magic numbers. Because the symmetry of a metal core can significantly affect the electronic structure of a nanocluster, this method takes the shape of the core into account in determining the order of group orbital levels. By taking nanoclusters as superatoms, a highly positively charged core is established by removing the ligands and staples. The superatomic orbitals split into group orbitals at different energy levels because of the nonspherical shape of the cluster core. Therefore, the electron configuration of the nonmagic-number nanocluster can be qualitatively analyzed without quantum chemical calculations, which is very important for understanding the stability of the cluster.