A silver cluster having the composition Ag9(H 2MSA)7 (H2MSA = mercaptosuccinic acid) was synthesized in macroscopic quantities using a solid-state route. The clusters were purified by PAGE and characterized by UV-vis, FTIR, luminescence, and NMR spectroscopy, TEM, XPS, XRD, TG, SEM/EDAX, elemental analysis, and ESI MS. The solid-state route provides nearly pure Ag9 clusters, and nanoparticle contamination was insignificant for routine studies. Formation of various clusters was observed by modifying the conditions. The effect of ligands on the synthesis was checked. The cluster decomposed slowly in water, and the decomposition followed first-order kinetics. However, it could be stabilized in solvent mixtures and in the solid state. Such materials may be important in cluster research because of their characteristic absorption profiles, which are similar to those of Au25 and Au38. The cluster showed luminescence with a quantum yield of 8 × 10-3 at 5 °C. © 2010 American Chemical Society.

Pradeep Thalappil

Department Of Chemistry

Thumu Udaya Bhaskara Rao

CHARACTERISTIC ABSORPTION

Elemental analysis

First order kinetics

FTIR

MACROSCOPIC QUANTITIES

MERCAPTOSUCCINIC ACIDS

NANOPARTICLE CONTAMINATION

NMR spectroscopy

QUANTUM CLUSTERS

SILVER CLUSTER

SOLID-STATE ROUTES

Solvent mixtures

Acids

chelation

chemical analysis

Luminescence

Nuclear magnetic resonance spectroscopy

quantum yield

quantum theory

Gold

nanoparticle

Silver

solvent

THIOMALIC ACID

Water

Absorption

article

contamination

decomposition

electrospray mass spectrometry

Energy dispersive X ray analysis

infrared spectroscopy

polyacrylamide gel electrophoresis

Quantum chemistry

Scanning electron microscopy

solid state

synthesis

thermogravimetry

Transmission electron microscopy

Ultraviolet spectroscopy

X ray analysis

X ray diffraction

X ray photoelectron spectroscopy

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Journal of the American Chemical Society

Recent reports have shown that the intercluster reaction is a new synthetic strategy to prepare alloy clusters. In this work, we performed an intercluster reaction between silver clusters and produced highly ionizable Ag-S-type clusters; we examined their formation by mass spectrometry. [Ag18(TPP)10H16]2+ (Ag18), a highly reactive hydride and phosphine-protected silver cluster, was used as a sacrificial cluster in this synthesis. An intercluster reaction between Ag18 and smaller silver-chalcogenolate clusters (SCC) resulted in a new cluster, [Ag34S3SBB20(CF3COO)6]2+. The cluster showed an NIR emission at around 1100 nm. The cluster composition was confirmed by high-resolution electrospray ionization mass spectrometry (ESI-MS), thermogravimetry (TGA), and X-ray photoelectron spectroscopy (XPS). © 2019 The Royal Society of Chemistry.

Dalton Transactions

Formation of an NIR-emitting Ag34S3SBB20(CF3COO)62+ cluster from a hydride-protected silver cluster

Abstract: Materials emitting white luminescence are receiving increasing attention due to their potential applications in electroluminescent devices, information displays and fluorescent sensors. To produce white light, one must have either three primary colors, blue, green and red or two colors, blue and orange. In this paper, we have used thiol/phosphine protected red luminescent silver nanoclusters (Ag NCs), [Ag29(BDT)12(PPh3)4]3-(BDT=1,3-benzenedithiol), [AuxAg29-x(BDT)12(PPh3)4]3- and Ag 29(LA) 12 (LA = lipoic acid) as one of the fluorophores for white light emission. These clusters are mixed with blue luminescent silicon nanoparticles (Si NPs) and green luminescent fluorescein isothiocyanate (FITC). The mixtures show white luminescence with CIE coordinates of (0.31, 0.34), (0.33, 0.35) and (0.29, 0.31) which are in good agreement with pure white light (0.33, 0.33). The other clusters with yellow, blue, orange, etc., luminescence can also be used to make white light. This work provides a prospective pathway for white light emission based on atomically precise noble metal NCs. Graphical abstract: Synopsis Monolayer protected noble metal nanoclusters such as [Ag29(BDT)12(PPh3)4]3-(BDT=1,3-benzenedithiol), [AuxAg29-x(BDT)12(PPh3)4]3- and Ag 29(LA) 12 (LA = lipoic acid) are used as red luminophores which can produce white light emission when mixed with blue luminescent silicon nanoparticles (Si NPs) and green luminescent fluorescein isothiocyanate (FITC). The mixtures produce white luminescence with CIE (Commission Internationale d’Eclair) coordinates of (0.31, 0.34), (0.33, 0.35) and (0.29, 0.31), respectively. All-cluster-based white light emission is indeed possible.[Figure not available: see fulltext.]. © 2018, Indian Academy of Sciences.

Fulltext

Journal of Chemical Sciences

Atomically precise cluster-based white light emitters §

Nanoparticles rival pharmaceuticals in synthetic inefficiency, in particular as measured by process mass intensity, with by far the largest contribution to waste being from solvents. We have therefore developed a greener method of synthesizing silver nanoparticles using a paste format instead of a metal salt solution. The paste-based synthesis requires 87% less solvent yet still produces exclusively Na4Ag44(p-MBA)30 nanoparticles, without size sorting, with 89% yield. By using a stoichiometric silver-thiolate polymer as a precursor to intimately mix the metal atoms and ligands, and by using a small amount of liquid to form a paste to promote mass transport, the heterogeneity and kinetics problems that are associated with entirely solid-state syntheses were avoided. Because the nanoparticle product was also a paste, solvent use for postprocessing was minimized. Use of the silver-thiolate polymer can also reduce health risks associated with hazardous free thiols in conventional solution-phase syntheses. Using this strategy, the process mass intensity was reduced from ∼1800 for the solution-phase reaction to ∼200 and ∼100 for the paste-based reaction with and without protonation of the ligands, respectively. © 2017 American Chemical Society.

Journal of Physical Chemistry C

High-Yield Paste-Based Synthesis of Thiolate-Protected Silver Nanoparticles

Reactivity of monolayer protected atomically precise clusters of noble metals is of significant research interest. To date very few experimental data are available on the reaction thermodynamics of such clusters. Here we report a calorimetric study of the reaction of glutathione (GSH) protected silver clusters in the presence of excess ligand, GSH, using isothermal titration calorimetry (ITC). We have studied Ag11(SG)7 and Ag32(SG)19 clusters and compared their reactivity with GSH protected silver nanoparticles (AgNPs) and silver ions. Clusters show intermediate reactivity toward excess ligand compared to nanoparticles and silver ions. Several control experiments were performed to understand the degradation mechanism of these silver clusters and nanoparticles. The effect of dissolved oxygen in the degradation process was studied in detail, and it was found that it did not have a significant role, although alternate pathways of degradation with the involvement of oxygen cannot be ruled out. Direct confirmation of the fact that functionalized metal clusters fall in-between NPs and atomic systems in their stability is obtained experimentally for the first time. Several other thermophysical parameters of these clusters were also determined, including density, speed of sound, isentropic compressibility, and coefficient of thermal expansion. © 2017 American Chemical Society.

Reactivity of Monolayer Protected Silver Clusters toward Excess Ligand: A Calorimetric Study

We report the synthesis and unique reactivity of a new green dithiol protected cluster (DTPC), Ag51(BDT)19(TPP)3 (BDT and TPP are 1,3-benzenedithiol and triphenylphosphine, respectively). The cluster composition was confirmed by electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI) mass spectrometric studies as well as by other supporting data. Surprisingly, the chemical reactivity between this DTPC and Au25(SR)18 involves only metal ion exchange in Au25(SR)18 without any ligand exchange, while reactions between monothiol protected clusters (MTPCs) show both metal and ligand exchange, an example being the reaction between Ag25DMBT18 and Au25PET18 (where DMBT and PET are 2,4-dimethylbenzenethiol and phenylethanethiol, respectively). The conclusions have been confirmed by the reaction of another DTPC, Ag29(BDT)12(TPP)4 with Au25BT18 (where BT corresponds to butanethiol) in which only metal exchange happens in Au25BT18. We also show the conversion of Ag51(BDT)19(TPP)3 to Ag29(BDT)12(TPP)4 in the presence of a second monothiol, DMBT which does not get integrated into the product cluster. This is completely different from the previous understanding wherein the reaction between MTPCs and a second thiol leads to either mixed thiol protected clusters with the same core composition or a completely new cluster core protected with the second thiol. The present study exposes a new avenue of research for monolayer protected clusters, which in turn will give additional impetus to explore the chemistry of DTPCs. © 2017 The Royal Society of Chemistry.

Nanoscale

Unusual reactivity of dithiol protected clusters in comparison to monothiol protected clusters: Studies using Ag51(BDT)19(TPP)3 and Ag29(BDT)12(TPP)4

Ag9 quantum cluster through a solid-state route

High Yield, Large Scale Synthesis of Thiolate-Protected Ag7Clusters

Chemical Society Reviews

Atomic and electronic structure of gold clusters: understanding flakes, cages and superatoms from simple concepts

Origin of Magic Stability of Thiolated Gold Clusters: A Case Study on Au25(SC6H13)18

Chemistry of Materials

Synthesis and Chiroptical Study ofd/l-Penicillamine-Capped Silver Nanoclusters

Journal	Journal of the American Chemical Society
ISSN	00027863
Open Access	No