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.

Pradeep Thalappil

Department Of Chemistry

C. K. Manju

Debasmita Ghosh

Mohammad Bodiuzzaman

Electrodeposition

Electrospray ionization

Hydrides

Infrared devices

Mass spectrometry

Phosphorus compounds

Photoionization

Silver

Thermogravimetric analysis

X ray photoelectron spectroscopy

ALLOY CLUSTER

Electrospray ionization mass spectrometry

High resolution

INTER CLUSTERS

NIR EMISSION

SILVER CLUSTER

Synthetic strategies

Silver compounds

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

Dalton Transactions

Two ligand-protected nanoscale silver moieties, [Ag46(SPhMe2)24(PPh3)8](NO3)2 and [Ag40(SPhMe2)24(PPh3)8](NO3)2 (abbreviated as Ag46 and Ag40, respectively) with almost the same shell but different cores were synthesized simultaneously. As their external structures are identical, the clusters were not distinguishable and become co-crystallized. The occupancy of each cluster was 50 %. The outer shell of both is composed of Ag32S24P8, which is reminiscent of fullerenes, and it encapsulates a well-studied core, Ag14 and a completely new core, Ag8, which correspond to a face-centered cube and a simple cube, respectively, resulting in the Ag46 and Ag40 clusters. The presence of two entities (Ag40 and Ag46 clusters) in a single crystal and their molecular formulae were confirmed by detailed electrospray ionization mass spectrometry. The optical spectrum of the mixture showed unique features which were in good agreement with the results from time-dependent density functional theory (TD-DFT). © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Angewandte Chemie - International Edition

Camouflaging Structural Diversity: Co-crystallization of Two Different Nanoparticles Having Different Cores But the Same Shell

An intercluster reaction between Au25(PET)18 and Ir9(PET)6 producing the alloy cluster, Au22Ir3(PET)18 exclusively, is demonstrated where the ligand PET is 2-phenylethanethiol. Typical reactions of this kind between Au25(PET)18 and Ag25(SR)18, and other clusters reported previously, produce mixed cluster products. The cluster composition was confirmed by detailed high-resolution electrospray ionization mass spectrometry (ESI MS) and other spectroscopic techniques. This is the first example of Ir metal incorporation in a monolayer-protected noble metal cluster. The formation of a single product was confirmed by thin layer chromatography (TLC). Density functional theory (DFT) calculations suggest that the most favorable geometry of the Au22Ir3(PET)18 cluster is one wherein the three Ir atoms are arranged triangularly with one Ir atom at the icosahedral core and the other two on the icosahedral shell. Significant contraction of the metal core was observed due to strong Ir-Ir interactions. © 2017 American Chemical Society.

Journal of Physical Chemistry Letters

Au22Ir3(PET)18: An Unusual Alloy Cluster through Intercluster Reaction

We report an attempt to probe into the energy demand of the fragmentation of atomically precise silver clusters using collision induced dissociation mass spectrometry. Energy resolved collisions of several gas phase ions of clusters, Ag29(S2R)12, Ag25(SR)18, and Ag44(SR)30, reveal distinct fragmentation kinetics involving charge separation. The fragmentation pattern of [Ag25(SR)18]- is found to be different from its structural analog, [Au25(SR)18]-. Survival yield analysis has been used to establish a direct comparison between the stability of the ions of these clusters, which reveals that [Ag29(S2R)12]3- is the most stable cluster ion, followed by [Ag25(SR)18]- and [Ag44(SR)30]4-. Gas phase stabilities reflect their solution phase stabilities, indicating that the molecular nature of the clusters is retained in the gas phase, too. We further report that fragmentation occurs in a stepwise fashion, conserving the closed shell electronic stability of the parent ion at each step. Such studies are important in understanding the electronic and geometric stability of cluster ions and their fragments. © 2017 American Chemical Society.

Journal of Physical Chemistry C

Dissociation of Gas Phase Ions of Atomically Precise Silver Clusters Reflects Their Solution Phase Stability

We report the formation of naked cluster ions of silver of specific nuclearities, uncontaminated by other cluster ions, derived from monolayer-protected clusters. The hydride and phosphine co-protected cluster, [Ag18(TPP)10H16]2+ (TPP, triphenylphosphine), upon activation produces the naked cluster ion, Ag17 +, exclusively. The number of metal atoms present in the naked cluster is almost the same as that in the parent material. Two more naked cluster ions, Ag21 + and Ag19 +, were also formed starting from two other protected clusters, [Ag25(DPPE)8H22]3+ and [Ag22(DPPE)8H19]3+, respectively (DPPE, 1,2-bis(diphenylphosphino)ethane). By systematic fragmentation, naked clusters of varying nuclei are produced from Ag17 + to Ag1 + selectively, with systematic absence of Ag10 +, Ag6 +, and Ag4 +. A seemingly odd number of cluster ions are preferred due to the stability of the closed electronic shells. Sequential desorption of dihydrogen occurs from the cluster ion, Ag17H14 +, during the formation of Agn +. A comparison of the pathways in the formation of similar naked cluster ions starting from two differently ligated clusters has been presented. This approach developed bridges the usually distinct fields of gas-phase metal cluster chemistry and solution-phase metal cluster chemistry. We hope that our findings will enrich nanoscience and nanotechnology beyond the field of clusters. © 2017 American Chemical Society.

Fulltext

ACS Nano

Sequential Dihydrogen Desorption from Hydride-Protected Atomically Precise Silver Clusters and the Formation of Naked Clusters in the Gas Phase

We present the first example of intercluster reactions between atomically precise, monolayer protected noble metal clusters using Au25(SR)18 and Ag44(SR)30 (RS- = alkyl/aryl thiolate) as model compounds. These clusters undergo spontaneous reaction in solution at ambient conditions. Mass spectrometric measurements both by electrospray ionization and matrix assisted laser desorption ionization show that the reaction occurs through the exchange of metal atoms and protecting ligands of the clusters. Intercluster alloying is demonstrated to be a much more facile method for heteroatom doping into Au25(SR)18, as observed by doping up to 20 Ag atoms. We investigated the thermodynamic feasibility of the reaction using DFT calculations and a tentative mechanism has been presented. Metal core-thiolate interfaces in these clusters play a crucial role in inducing these reactions and also affect rates of these reactions. We hope that our work will help accelerate activities in this area to establish chemistry of monolayer protected clusters. © 2015 American Chemical Society.

Journal of the American Chemical Society

Intercluster Reactions between Au25(SR)18 and Ag44(SR)30

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

Journal	Data powered by TypesetDalton Transactions
Publisher	Data powered by TypesetRoyal Society of Chemistry
ISSN	14779226
Open Access	No