A Strategy for Generating Naked‐Metal Clusters for Gas‐Phase Reactivity Studies by FTICR–MS

Abstract

Cluster reactivity in the gas phase has been probed extensively with clusters generated by using a variety of custombuilt sources. These include pulsed-laser vaporisation, continuous-operation ovens, fast-atom and secondary-ion sputtering, dc discharge, and pulsed-arc cluster-ion sources.[1] All generate an assortment of clusters of different nuclearities, and MS n techniques make selection of a particular sized cluster relatively straightforward. Both homo-and heteronuclear clusters are known.[2] All of these techniques employ a similar strategy to cluster synthesis; that is, the target is vaporised, the gas-phase metal atoms condensed, and the resulting clusters examined by mass spectrometry. We report herein an entirely different approach for the production of bare-metal gas-phase clusters, in which presynthesised transition-metal-carbonyl-cluster anions are delivered into the gas phase by a standard electrospray ionisation (ESI) source and stripped free of ligands by using collision-induced dissociation (CID) at the skimmer cone. The benefits of this approach are high yields of a specific cluster, no requirement for a special source, easy access to heteronuclear clusters and/ or those with interstitial atoms, and a vast library of known clusters to draw from.Because mixed-metal-carbonyl clusters are currently extensively used as precursors for metal nanoparticle catalysts (the clusters are absorbed inside mesoporous silica and calcined to remove the ligands), [3] examination of their gasphase reactivity may provide insight into their action as[*] Dr.

Theory meets experiment: Gas-phase chemistry of coinage metals

“…Electrospray ionization (ESI [139,140]) brought very powerful technique for gas-phase mechanistic studies [115,[141][142][143]. Using hard ionization conditions (large collision energies of the electrospray droplets with the drying gas [144]), highly reactive species can be generated and consequently used as models for catalysis.…”

Tailored Nanoparticles for Clean Technology–Achieving Size and Shape Control

“…However, studies by McIndoe et al [42] demonstrated that chemically synthesized atomically precise metal clusters could be used as precursors of naked metal clusters. Similarly, reactivity studies of partially ligated gas-phase metal clusters can be performed using chemically made, atomically precise clusters as a source, and easily installed and inexpensive modifications to electrospray ionization mass spectrometers [43].…”

Identification of clusters from reactions of ruthenium arene anticancer complex with glutathione using nanoscale liquid chromatography fourier transform ion cyclotron mass spectrometry combined with 18O-labeling

“…Two Ru III complexes are currently undergoing clinical trials as anti-cancer agents, and Ru II arene complexes have shown promising activity in model cancer systems [1]. Ruthenium has seven isotopes, making the mass isotopic pattern of ion peaks of ruthenium-containing compounds characteristic, yet complicated [2][3][4][5][6]. In our previous work [2,3,[7][8][9], mass spectra acquired by electrospray ionization (ESI-MS) equipped with a quadrupole mass analyzer allowed unambiguous assignment of singly charged ion peaks of mononuclear ruthenium arene complexes as well as their adducts with amino acids, peptides, and DNA.…”