High-energy collision induced dissociation of iridium hexa-halide dianions: Observation of triple electron detachment and other decay pathways

W E Boxford, M O A El Ghazaly, C E H Dessent, S B Nielsen

Research output: Contribution to journalArticlepeer-review

Abstract

Lifetimes of the IrBr62- and IrCl62- gas-phase ions were measured in an electrostatic ion storage ring its 3.3 +/- 0.1 s and 3.1 +/- 0.1 s, respectively. The lifetimes indicate that the dianions are not subject to spontaneous decay under ambient conditions, since they are associated with decay resulting solely from high-energy collisions with residual gas (similar to 5 x 10(-11) Torr) that is present in the ring. To further investigate the high-energy collisional decay dynamics, IrBr62- and IrCl62- were subjected to high-energy collision induced dissociation measurements in an accelerator mass spectrometer (ion translational energy in laboratory frame = 100 keV). A number of daughter ions were formed following the high-energy collisions (e.g., IrCl62- produced IrCl6-, IrCl5, IrCl4-, IrCl3 and Cl). The presence of the intact monoanion (i.e., IrCl6-) indicates that electron detachment is a prominent decay process, in contrast to low-energy collisional excitation where IrCl5 and Cl- are produced via ionic fragmentation. The predominance of electron detachment occurring is a result of high-energy collisions was further illustrated by charge-reversal measurements where cationic daughter fragments were observed, consistent with triple electron detachment. This measurement indicates that high-energy collisional activation of dianions should represent a general approach for studying triple electron detachment of molecular anions. (c) 2005 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)60-64
Number of pages5
JournalINTERNATIONAL JOURNAL OF MASS SPECTROMETRY
Volume244
Issue number1
DOIs
Publication statusPublished - 15 Jun 2005

Keywords

  • multiply charged ions
  • dianions
  • ion storage ring
  • high-energy collision induced dissociation
  • triple electron detachment
  • MULTIPLY-CHARGED ANIONS
  • GAS-PHASE
  • METAL-COMPLEX
  • IONS
  • STABILITY
  • SPECTROSCOPY
  • DYNAMICS

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