Dissociative and Reactive Hyperthermal Ion−Surface Collisions with Langmuir−Blodgett Films Terminated by CF3(CH2)n−, n-Perfluoroalkyl, or n-Alkyl Groups

Gu, Chungang; Wysocki, Vicki H.; Harada, Atsuhiro; Takaya, and Hiroaki; Kumadaki, Itsumaro

doi:10.1021/ja990719a

Cited by 20 publications

(37 citation statements)

References 70 publications

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“…V transfer in collisions of ions with different surfaces (Cooks, Ast, & Mabud, 1990;Miller et al, 1994;Gu et al, 1999;Smith et al, 2002). The major limitation of these methods is that they require a prior knowledge of the BDG, which is available for a very limited number of ions.…”

Section: B Thermometer Ion Methodsmentioning

confidence: 99%

Collisional activation of peptide ions in FT‐ICR mass spectrometry

Laskin

Futrell

2003

Mass Spectrometry Reviews

176

179

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In the last decade, the characterization of complex molecules, particularly biomolecules, became a focus of fundamental and applied research in mass spectrometry. Most of these studies utilize tandem mass spectrometry (MS/MS) to obtain structural information for complex molecules. Tandem mass spectrometry (MS/MS) typically involves the mass selection of a primary ion, its activation by collision or photon excitation, unimolecular decay into fragment ions characteristic of the ion structure and its internal excitation, and mass analysis of the fragment ions. Although the fundamental principles of tandem mass spectrometry of relatively small molecules are fairly well-understood, our understanding of the activation and fragmentation of large molecules is much more primitive. For small ions, a single energetic collision is sufficient to dissociate the ion; however, this is not the case for complex molecules. For large ions, two fundamental limits severely constrain fragmentation in tandem mass spectrometry. First, the center-of-mass collision energy-the absolute upper limit of energy transfer in a collision process-decreases with increasing mass of the projectile ion for fixed ion kinetic energy and neutral mass. Secondly, the dramatic increase in density of states with increasing internal degrees of freedom of the ion decreases the rate of dissociation by many orders of magnitude at a given internal energy. Consequently, most practical MS/MS experiments with complex ions involve multiple-collision activation (MCA-CID), multi-photon activation, or surface-induced dissociation (SID). This review is focused on what has been learned in recent research studies concerned with fundamental aspects of MCA-CID and SID of model peptides, with an emphasis on experiments carried out with Fourier transform ion cyclotron resonance mass spectrometers (FT-ICR MS). These studies provide the first quantitative comparison of gas-phase multiple-collision activation and SID of peptide ions. Combining collisional energy-resolved data with RRKM-based modeling revealed the effect of peptide size and identity on energy transfer in collisions-very important characteristics of ion activation from fundamental and the analytical perspectives. Finally, the combination of FT-ICR with SID was utilized to carry out the first time-resolved experiments that examine the kinetics of peptide fragmentation. This has lead to the discovery that the time-dependence of ion dissociation varies smoothly up to a certain collision energy, and then shifts dramatically to a time-independent, extensive dissociation. This near-instantaneous "shattering" of the ion generates a large number of relatively small fragment ions. Shattering of ions on surfaces opens up a variety of dissociation pathways that are not accessible with multiple-collision and multiphoton excitation.

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Section: B Thermometer Ion Methodsmentioning

confidence: 99%

Collisional activation of peptide ions in FT‐ICR mass spectrometry

Laskin

Futrell

2003

Mass Spectrometry Reviews

176

179

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“…Organic thin films on metal substrates substantially reduce neutralization of projectile ions. Surfaces commonly used in SID experiments include self-assembled monolayers of n-alkanethiols (HSAM) and their fluorinated analogs (FSAM) on gold or silver (Morris et al, 1992;Cooks et al, 1994;Dongre, Somogyi, & Wysocki, 1996), thin films of a liquid perfluoropolyether (Koppers et al, 1997), Langmuir-Blodgett (L-B) films (Gu et al, 1999) or highly oriented pyrolytic graphite (Beck et al, 1996a). Thin films of insulating materials (such as metal halides or diamond) on metal substrates have a great potential for efficient dissociation of large molecules (Laskin & Futrell, 2003b).…”

Section: Choice Of the Sid Targetmentioning

confidence: 99%

Activation of large lons in FT‐ICR mass spectrometry

Laskin

Futrell

2004

Mass Spectrometry Reviews

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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“…Of course, the penetration depth depends strongly on the kinetic energy, with a calculated penetration depth into an alkane thiolate surface of about 3.5 Å for 60 eV impact. 82 Wysocki and co-workers 83 have reported studies of the depth dependence of an ion/surface reaction using isotopically labeled Langmuir-Blodgett films as adsorbates. They reported that for low collision energies it is predominantly the terminal group of the adsorbate that reacts with the incoming ion, the interaction region being confined to the outermost few atoms of the surface monolayer.…”

Section: Characteristic Parametersmentioning

confidence: 99%

“…Several experimental observations, especially those using isotopically labeled surfaces, establish that reactive scattering is limited to the topmost few atomic layers of SAM, 26 as well as Langmuir-Blodgett surfaces. 24,83 …”

Section: F Target Surfacementioning

confidence: 99%

Collisions of ions with surfaces at chemically relevant energies: Instrumentation and phenomena

Grill¹,

Shen²,

Evans³

et al. 2001

Review of Scientific Instruments

202

249

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Articles you may be interested inMeasuring the internal energies of species emitted from hypervelocity nanoprojectile impacts on surfaces using recalibrated benzylpyridinium probe ions High-energy ions and atoms sputtered and reflected from a magnetron source for deposition of magnetic thin films J. Vac. Sci. Technol. A 23, 671 (2005); 10. 1116/1.1943452 Surface induced dissociations of protonated ethanol monomer, dimer and trimer ions: Trimer break-down graph from the collision energy dependence of projectile fragmentation An overview of gaseous ion/surface collisions is presented, with special emphasis on the behavior of polyatomic projectile ions at hyperthermal collision energies ͑1-100 eV͒ and the instrumentation needed for such studies. The inelastic and reactive processes occurring during ion/surface collisions are described in terms of several archetypes, viz., elastic and quasielastic scattering, chemical sputtering leading to release of surface material, inelastic scattering leading to surface-induced dissociation ͑SID͒ of the projectile, ion/surface reactions, and soft landing. Parameters that are important in ion/surface interactions are discussed, including the interaction time, the conversion of translational to internal energy, the translational energies of the scattered ions, the effects of scattering angle, and the influence of the nature of the surface. Different types of tandem mass spectrometers, built specifically to study ion/surface collision phenomena, are discussed and the advantages and disadvantages of the individual designs are compared. The role of SID as a technique in bioanalytical mass spectrometry is illustrated and this inelastic collision experiment is compared and contrasted with gas-phase collision-induced dissociation, the standard method of tandem mass spectrometry. Special emphasis is placed on reactive scattering including the use of ion/surface reactions for surface chemical analysis and for surface chemical modification.

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Dissociative and Reactive Hyperthermal Ion−Surface Collisions with Langmuir−Blodgett Films Terminated by CF₃(CH₂)_n−, n-Perfluoroalkyl, or n-Alkyl Groups

Cited by 20 publications

References 70 publications

Collisional activation of peptide ions in FT‐ICR mass spectrometry

Collisional activation of peptide ions in FT‐ICR mass spectrometry

Activation of large lons in FT‐ICR mass spectrometry

Collisions of ions with surfaces at chemically relevant energies: Instrumentation and phenomena

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