Unimolecular Decomposition in Ion Cyclotron Resonance Traps: Kinetic Energy Release and Microsecond-Scale Kinetics

Rakov, V. Sergey

doi:10.1255/ejms.497

Cited by 3 publications

(3 citation statements)

References 27 publications

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“…Kinetic energy distributions of scattered ions have been measured for benzene and Cr(CO) 6 þ as precursor ions (Rakov et al, 2000;Rakov & Futrell, 2002). For Cr(CO) 6 þ and its fragments the most probable kinetic energy of scattered ions is lower than 1 eV and the distributions are fairly narrow (<2 eV FWHM).…”

Section: Kinetic Energy Of Scattered Ionsmentioning

confidence: 99%

“…Kinetic energy distributions of ions derived from benzene are centered at approximately 4 eV (Rakov et al, 2000). However, it has been demonstrated that these distributions have been biased by the potential difference between the surface and the ICR cell (Rakov & Futrell, 2002). Therefore, the most probable energy for benzene fragments has been significantly overestimated.…”

Section: Kinetic Energy Of Scattered Ionsmentioning

confidence: 99%

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Activation of large lons in FT‐ICR mass spectrometry

Laskin

Futrell

2004

Mass Spectrometry Reviews

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177

146

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The advent of soft ionization techniques, notably electrospray and laser desorption ionization methods, has enabled the extension of mass spectrometric methods to large molecules and molecular complexes. This both greatly extends the applications of mass spectrometry and makes the activation and dissociation of complex ions an integral part of these applications. This review emphasizes the most promising methods for activation and dissociation of complex ions and presents this discussion in the context of general knowledge of reaction kinetics and dynamics largely established for small ions. We then introduce the characteristic differences associated with the higher number of internal degrees of freedom and high density of states associated with molecular complexity. This is reflected primarily in the kinetics of unimolecular dissociation of complex ions, particularly their slow decay and the higher energy content required to induce decomposition-the kinetic shift (KS). The longer trapping time of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) significantly reduces the KS, which presents several advantages over other methods for the investigation of dissociation of complex molecules. After discussing general principles of reaction dynamics related to collisional activation of ions, we describe conventional ways to achieve single-and multiple-collision activation in FT-ICR MS. Sustained off-resonance irradiation (SORI)-the simplest and most robust means of introducing the multiple collision activation process-is discussed in greatest detail. Details of implementation of this technique, required control of experimental parameters, limitations, and examples of very successful application of SORI-CID are described. The advantages of high mass resolving power and the ability to carry out several stages of mass selection and activation intrinsic to FT-ICR MS are demonstrated in several examples. Photodissociation of ions from small molecules can be effected using IR or UV/vis lasers and generally requires tuning lasers to specific wavelengths and/ or utilizing high flux, multiphoton excitation to match energy levels in the ion. Photodissociation of complex ions is much easier to accomplish from the basic physics perspective. The quasi-continuum of vibrational states at room temperature makes it very easy to pump relatively large amounts of energy into complex ions and infrared multiphoton dissociation (IRMPD) is a powerful technique for characterizing large ions, particularly biologically relevant molecules. Since both SORI-CID and IRMPD are slow activation methods they have many common characteristics. They are also distinctly different because SORI-CID is intrinsically selective (only ions that have a cyclotron frequency close to the frequency of the excitation field are excited), whereas IRMPD is not (all ions that reside on the optical path of the laser are excited). There are advantages and disadvantages to each technique and in many applications they complement each other. In contrast wi...

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Section: Kinetic Energy Of Scattered Ionsmentioning

confidence: 99%

Section: Kinetic Energy Of Scattered Ionsmentioning

confidence: 99%

Activation of large lons in FT‐ICR mass spectrometry

Laskin

Futrell

2004

Mass Spectrometry Reviews

Self Cite

177

146

View full text Add to dashboard Cite

show abstract

“…The TOF-SIMS analysis, in comparison, is much faster with only a few microseconds between the sputtering event and detection. Due to the significantly longer residence time of the energized secondary ions prior to analysis in FTICR-SIMS there is a much higher incidence of unimolecular decay and fragmentation as compared to TOF-SIMS. ,, The lower fragmentation yield observed in TOF-SIMS spectra is advantageous for the interpretation of SIMS spectra and for improved detection of secondary ions because signal intensity is distributed over fewer peaks.…”

Section: Resultsmentioning

confidence: 99%

In Situ Reactivity and TOF-SIMS Analysis of Surfaces Prepared by Soft and Reactive Landing of Mass-Selected Ions

2010

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An instrument has been designed and constructed that enables in situ reactivity and time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis of surfaces prepared or modified through soft and reactive landing of mass-selected polyatomic cations and anions. The apparatus employs an electrospray ion source coupled to a high transmission electrodynamic ion funnel, two focusing collision quadrupoles, a large 19 mm diameter quadrupole mass filter, and a quadrupole bender that deflects the ion beam, thereby preventing neutral contaminants from impinging on the deposition surface. The ion soft landing apparatus is coupled to a commercial TOF-SIMS instrument permitting the introduction of surfaces into vacuum and SIMS analysis before and after ion deposition without breaking vacuum. To facilitate a comparison of the current TOF-SIMS instrument with the in situ Fourier transform ion cyclotron resonance (FTICR-SIMS) deposition apparatus constructed previously, dications of the cyclic peptide Gramicidin S (GS) and the photoactive organonometallic complex ruthenium tris-bipyridine (Ru(bpy)(3)) were soft-landed onto fluorinated self-assembled monolayer (FSAM) on gold surfaces. In both cases, similarities and differences were observed in the secondary ion mass spectra, with the TOF-SIMS results, in general, characterized by greater sensitivity, larger dynamic range, less fragmentation, and fewer in-plume reactions than the corresponding FTICR-SIMS spectra. The charge reduction kinetics of both the doubly and singly protonated GS cations on the FSAM surface were also examined as was the influence of the primary gallium ion (Ga(+)) flux on the efficiency of these processes. In addition, we demonstrate that the new instrument enables detailed studies of the reactivity of catalytically active species immobilized by soft and reactive landing toward gaseous reagents.

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Current literature in mass spectrometry

2002

J. Mass Spectrom.

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In order to keep subscribers up‐to‐date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of mass spectrometry. Each bibliography is divided into 11 sections: 1 Books, Reviews & Symposia; 2 Instrumental Techniques & Methods; 3 Gas Phase Ion Chemistry; 4 Biology/Biochemistry: Amino Acids, Peptides & Proteins; Carbohydrates; Lipids; Nucleic Acids; 5 Pharmacology/Toxicology; 6 Natural Products; 7 Analysis of Organic Compounds; 8 Analysis of Inorganics/Organometallics; 9 Surface Analysis; 10 Environmental Analysis; 11 Elemental Analysis. Within each section, articles are listed in alphabetical order with respect to author (3 Weeks journals ‐ Search completed at 24th. July 2002)

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Unimolecular Decomposition in Ion Cyclotron Resonance Traps: Kinetic Energy Release and Microsecond-Scale Kinetics

Cited by 3 publications

References 27 publications

Activation of large lons in FT‐ICR mass spectrometry

Activation of large lons in FT‐ICR mass spectrometry

In Situ Reactivity and TOF-SIMS Analysis of Surfaces Prepared by Soft and Reactive Landing of Mass-Selected Ions

Current literature in mass spectrometry

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