ESI/MS investigation of routes to the formation of silver hydride nanocluster dications [Ag x H x−2 L y ] 2+ and gas-phase unimolecular chemistry of [Ag 10 H 8 L 6 ] 2+
| Autor: | Athanasios Zavras, George N. Khairallah, Vlasta Bonačić-Koutecký, Marjan Krstić, Philippe Dugourd, Richard A. J. O'Hair |
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| Přispěvatelé: | Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), ICAST, University of Split, Bio21 Molecular Science & Biotechnology Institute [Melbourne] (School of Chemistry), Faculty of Science [Melbourne], University of Melbourne-University of Melbourne |
| Rok vydání: | 2017 |
| Předmět: |
Hydrogen
electrospray mass spectrometry gas-phase ligated silver hydride nanoclusters Electrospray ionization Analytical chemistry chemistry.chemical_element 02 engineering and technology 010402 general chemistry 01 natural sciences Dissociation (chemistry) chemistry.chemical_compound [CHIM]Chemical Sciences Molecule Physical and Theoretical Chemistry Acetonitrile Instrumentation ComputingMilieux_MISCELLANEOUS Spectroscopy Chemistry Ligand Hydride 021001 nanoscience & nanotechnology Condensed Matter Physics 0104 chemical sciences Crystallography Mass spectrum [PHYS.PHYS.PHYS-CHEM-PH]Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph] 0210 nano-technology |
| Zdroj: | International Journal of Mass Spectrometry International Journal of Mass Spectrometry, Elsevier, 2017, 413, pp.97-105. ⟨10.1016/j.ijms.2016.05.022⟩ |
| ISSN: | 1387-3806 |
| Popis: | When the bis(diphenylphosphino)methane (dppm) ligated silver hydride nanocluster salt [Ag 3 (L) 3 ( μ 3 -H)](BF 4 ) 2 is allowed to react with NaBH 4 in a methanol/chloroform solution for 5 mins., and then diluted with acetonitrile and subjected to electrospray ionization mass spectrometry (ESI/MS), a range of silver hydride nanocluster dications are observed including: [Ag 8 H 6 L 5 ] 2+ and [Ag x H x−2 L 6 ] 2+ , where x = 9–15 and L = dppm. All of these clusters are no longer present in the ESI mass spectrum at 40 mins after mixing. Multistage mass spectrometry (MS n ) experiments were carried out to determine the fragmentation chemistry of [Ag 10 H 8 L 6 ] 2+ under conditions of collision-induced dissociation (CID). The initial CID reactions involve sequential loss of two ligands (L) to produce [Ag 10 H 8 L 4 ] 2+ . Further isolation and CID of [Ag 10 H 8 L 4 ] 2+ resulted in a rich series of product ions which arise from three classes of fragmentation reactions: (i) cluster fission to yield complementary ion pairs [Ag 10−x H 8-(x−1) L 4−y ] + and [Ag x H x−1 L y ] + (x = 1, 2 and 4); (ii) ligand loss associated with cluster fission to yield pairs of singly charged clusters [Ag 10−x H 8-(x−1) L 4−y ] + and [Ag x H x−1 L y−1 ] + (x = 1–4); (iii) ligand loss with concomitant loss of all the hydrides, presumably as four molecules of hydrogen to give the ligated silver cluster, [Ag 10 L 3 ] 2+ . The subsequent fragmentation reactions of the product ions were also examined. Most of the singly charged ligated silver hydride clusters fragment to form [Ag x H x−1 L y ] + . The exceptions are [Ag 9 H 8 L 2 ] + and [Ag 7 H 6 L 2 ] + which, upon ligand loss also release all of the hydrides to form the ligated silver clusters, [Ag 9 L] + and [Ag 7 L] + respectively. DFT calculations were carried out to examine how the cluster geometry changes for the following processes: [Ag 10 H 8 L 6 ] 2+ → [Ag 10 H 8 L 4 ] 2+ + 2L → [Ag 10 H 8 L 3 ] 2+ + L → [Ag 10 L 3 ] 2+ + 4H 2 . Losses of 2 L from [Ag 10 H 8 L 6 ] 2+ and L from [Ag 10 H 8 L 4 ] 2+ were calculated to be endothermic by 2.9 and 1.9 eV respectively, but the subsequent loss of 4H 2 from [Ag 10 H 8 L 3 ] 2+ is exothermic by 0.2 eV. |
| Databáze: | OpenAIRE |
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