A study of the dissociation of CH3CH2SH+ by collisional activation: Evidence of nonstatistical behavior

Chen, Yu‐Ju; Stimson, S.; Fenn, Patrick; Ng, C. Y.; Li, Wai‐Kee; L., N.

doi:10.1063/1.476241

Cited by 7 publications

(26 citation statements)

References 24 publications

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“…Most of bond-selective dissociation studies have been focused on the dissociation processes induced by photoexcitation. In our previous collision-induced dissociation (CID) studies − concerning the measurements of absolute total CID cross sections for collisions of CH 3 SH + (or CH 3 CH 2 SH + ) + Ar, we have obtained convincing evidence that bond-selective dissociations occur in these CID reactions. In the CID reaction of CH 3 SH + + Ar, the higher-energy product channel CH 3 + + SH, owing to C−S bond rupture, was found to be more favorable than the more stable product channel CH 2 SH + + H resulting from C−H cleavage.…”

Section: Introductionmentioning

confidence: 84%

Study of the Dissociation of CH₃SCH₃⁺ by Collisional Activation: Evidence of Nonstatistical Behavior

et al. 2002

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The collision-induced dissociation (CID) reaction of CH 3 SCH 3 + + Ar was studied in a triple-quadrupole, double-octopole ion-molecule reaction apparatus. The absolute total cross sections for the product ions CH 2 SH + /CH 3 S + , CH 2 S + , CHS + , and CH 3 + formed in the CID reaction have been measured in the centerof-mass kinetic energy (E cm ) range of 1-19 eV. Using the charge-transfer probing technique, we found that mass-47 product ions are formed in both the CH 2 SH + and CH 3 S + structures. The onsets for CH 2 SH + , CH 3 S + , CH 2 S + , CHS + , and CH 3 + are consistent with their thermochemical thresholds. The formation of the higherenergy product channel CH 3 S + + CH 3 , which involves C-S bond scission, is found to dominate in the E cm range immediately above its onset. The lower-energy channel corresponding to the formation CH 3 SCH 2 + + H is not found. The strong preference observed for the higher-energy channel is in accordance with the conclusions obtained from the CID studies of CH 3 SH + and CH 3 CH 2 SH + , providing further evidence that the CID of CH 3 SCH 3 + is also nonstatistical. The high yield of CH 3 S + + CH 3 is attributed to the more efficient translational-to-vibrational energy transfer for the C-S stretching modes with lower frequencies than to those for the C-H stretching modes with higher frequencies, along with weak coupling between these vibrational modes with significantly different frequencies of CH 3 SCH 3 + . In addition, the dissociation pathways deduced are consistent with the results of ab initio calculations at the G3 level.

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Section: Introductionmentioning

confidence: 84%

Study of the Dissociation of CH₃SCH₃⁺ by Collisional Activation: Evidence of Nonstatistical Behavior

et al. 2002

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“…Potential non-RRKM effects, such as those reported in references [82] and [83], are not included in these models. In principle, use of quasiclassical trajectory calculations enables accounting for such effects (e.g., refs [47,84,85].…”

Section: General Discussion Of the Methods And The Resultsmentioning

confidence: 99%

Classical trajectories and RRKM modeling of collisional excitation and dissociation of benzylammonium and tert-butyl benzylammonium ions in a quadrupole-hexapole-quadrupole tandem mass spectrometer

Knyazev

Stein²

2010

J. Am. Soc. Mass Spectrom.

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Collision-induced dissociation of the benzylammonium and the 4-tert-butyl benzylammonium ions was studied experimentally in an electrospray ionization quadrupole-hexapole-quadrupole tandem mass spectrometer. Ion fragmentation efficiencies were determined as functions of the kinetic energy of ions and the collider gas (argon) pressure. A theoretical Monte Carlo model of ion collisional excitation, scattering, and decomposition was developed. The model includes simulation of the trajectories of the parent and the product ions flight through the hexapole collision cell, quasiclassical trajectory modeling of collisional activation and scattering of ions, and Rice-Ramsperger-Kassel-Marcus (RRKM) modeling of the parent ion decomposition. The results of modeling demonstrate a general agreement between calculations and experiment. Calculated values of ion fragmentation efficiency are sensitive to initial vibrational excitation of ions, scattering of product ions from the collision cell, and distribution of initial ion velocities orthogonal to the axis of the collision cell. Three critical parameters of the model were adjusted to reproduce the experimental data on the dissociation of the benzylammonium ion: reaction enthalpy and initial internal and translational temperatures of the ions. Subsequent application of the model to decomposition of the t-butyl benzylammonium ion required adjustment of the internal ion temperature only. Energy distribution functions obtained in modeling depend on the average numbers of collisions between the ion and the atoms of the collider gas and, in general, have non-Boltzmann shapes. (J Am Soc Mass Spectrom 2010, 21, 425-439) © 2010 American Society for Mass Spectrometry F ragmentation of gaseous ions has long been an important source of information on the properties of these ions and the corresponding parent species. Studies of collision-induced dissociation (CID) mass spectra of many types of ions provide important information on their structure, thermochemistry, and other properties; recently, the main focus of such studies shifted to the analysis of large biomolecules, such as proteins and peptides (e.g., [1][2][3][4][5][6][7][8][9][10][11].As a result of many studies, the many features of collisional ion dissociation have been elucidated, including those of fragmentation of the ions of large biomolecules (e.g., [9,[12][13][14][15][16][17] and references therein). However, the factors that determine absolute and relative abundances of possible fragments are not well understood, certainly not to the point that would enable quantitative prediction of CID mass spectra. It is generally understood that the successful modeling of collisional ion dissociation would require correct quantitative description of three factors: (1) the chemical mechanism of fragmentation (i.e., the sequence of intramolecular rearrangements and decomposition and the potential energy surfaces of these processes), (2) rovibrational excitation of the parent ion as a result of collisions with the inert collider gas, a...

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“…This corresponds to the so-called shattering reaction mechanism, where the bond is broken largely before energy transfer between vibrational modes. It should be noted that the shattering mechanism can be important in driving the reactivity, as was, for example, noticed experimentally and theoretically by studying the dissociation of CH 3 SH + and CH 3 SCH þ 3 [179,180]. Shattering is a reaction mechanism that shirks the basic assumptions of statistical theory and thus any prediction based on this theoretical framework.…”

Section: Chemical Dynamicsmentioning

confidence: 95%

Theoretical Methods for Vibrational Spectroscopy and Collision Induced Dissociation in the Gas Phase

Gaigeot

Spezia

2014

Topics in Current Chemistry

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In this chapter we review recent advances in theoretical methods to understand and rationalize anharmonic vibrational spectroscopy (IR-MPD and IR-PD) and collision induced dissociations (CID) in the gas phase. We focused our attention on the application of molecular dynamics-based methods. DFT-based molecular dynamics was shown to be able to reproduce InfraRed Multi-Photon Dissociation (IR-MPD) and InfraRed Pre-Dissociation (IR-PD) action spectroscopy experiments, and help assign the vibrational bands, taking into account finite temperature, conformational dynamics, and various anharmonicities. Crucial examples of dynamical vibrational spectroscopy are given on the protonated Ala n H(+) series (related to IR-MPD in the 800-4,000 cm(-1) domain), ionic clusters (related to IR-PD in the 3,000-4,000 cm(-1) region), and neutral peptides (related to IR-MPD in the far-IR). We give examples from simple (e.g., cationized urea) to more complex (e.g., peptides and carbohydrates) molecular systems where molecular dynamics was particularly suited to understanding CID experiments.

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A study of the dissociation of CH3CH2SH+ by collisional activation: Evidence of nonstatistical behavior

Cited by 7 publications

References 24 publications

Study of the Dissociation of CH₃SCH₃⁺ by Collisional Activation: Evidence of Nonstatistical Behavior

Study of the Dissociation of CH₃SCH₃⁺ by Collisional Activation: Evidence of Nonstatistical Behavior

Classical trajectories and RRKM modeling of collisional excitation and dissociation of benzylammonium and tert-butyl benzylammonium ions in a quadrupole-hexapole-quadrupole tandem mass spectrometer

Theoretical Methods for Vibrational Spectroscopy and Collision Induced Dissociation in the Gas Phase

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A study of the dissociation of CH3CH2SH+ by collisional activation: Evidence of nonstatistical behavior

Cited by 7 publications

References 24 publications

Study of the Dissociation of CH3SCH3+ by Collisional Activation: Evidence of Nonstatistical Behavior

Study of the Dissociation of CH3SCH3+ by Collisional Activation: Evidence of Nonstatistical Behavior

Classical trajectories and RRKM modeling of collisional excitation and dissociation of benzylammonium and tert-butyl benzylammonium ions in a quadrupole-hexapole-quadrupole tandem mass spectrometer

Theoretical Methods for Vibrational Spectroscopy and Collision Induced Dissociation in the Gas Phase

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Study of the Dissociation of CH₃SCH₃⁺ by Collisional Activation: Evidence of Nonstatistical Behavior

Study of the Dissociation of CH₃SCH₃⁺ by Collisional Activation: Evidence of Nonstatistical Behavior