Internal energy distributions of tungsten hexacarbonyl ions after neutralization-Reionization

Sarka Beranova, Chrys Wesdemiotis

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

The internal energy distributions P(ε) transferred to W(CO)6 during the kiloelectronvolt collisions that occur upon neutralization-reionization (NR) have been estimated based on the relative abundances of the W(CO)0-6 products present in NR spectra (thermochemical method). The average internal energy of the incipient {W(CO)6}* ions arising after near thermoneutral neutralization with trimethylamine followed by reionization with O2 is ∼9 eV for 8-keV precursor ions and is mainly deposited during reionization, For comparison, the mean internal energy of {W(CO)6}* after electron ionization (EO or collisionally activated dissociation (CAD) is ∼ 6 eV. Making the neutralization step endothermic slightly increases the overall excitation gained; however, a large increase in endothermicity (> 16 eV) causes only a modest rise of the average internal energy (<2 eV). The P(ε) curve for NR increases exponentially up to ∼ 6 eV and levels off at higher energies.. showing that the probability of imparting large internal energies (6-17 eV) is high. In sharp contrast, the most probable excitation on CAD is ≤6 eV, and the probability of deposition of larger energies declines exponentially. The mean internal energies after CAD and NR decrease steadily when the kinetic energy is lowered. The structure (minima-maxima) observed in the P(ε) distribution for El, which most likely originates from Franck-Condon factors, is not reproduced in the distributions for NR or high energy CAD, despite the fact that all three methods involve electronic excitation. Because of the large internal energies transferred upon NR, NR mass spectrometry could be particularly useful in the differentiation of ionic isomers with high dissociation but low isomerization thresholds.

Original languageEnglish (US)
Pages (from-to)1093-1101
Number of pages9
JournalJournal of the American Society for Mass Spectrometry
Volume5
Issue number12
DOIs
StatePublished - Jan 1 1994

Fingerprint

Ions
Carbon Monoxide
Mass Spectrometry
Isomerization
Kinetic energy
Isomers
Ionization
Mass spectrometry
Electrons
hexacarbonyltungsten
trimethylamine

All Science Journal Classification (ASJC) codes

  • Structural Biology
  • Spectroscopy

Cite this

Internal energy distributions of tungsten hexacarbonyl ions after neutralization-Reionization. / Beranova, Sarka; Wesdemiotis, Chrys.

In: Journal of the American Society for Mass Spectrometry, Vol. 5, No. 12, 01.01.1994, p. 1093-1101.

Research output: Contribution to journalArticle

@article{c492f17c5ad043d19f96cd6689bf3432,
title = "Internal energy distributions of tungsten hexacarbonyl ions after neutralization-Reionization",
abstract = "The internal energy distributions P(ε) transferred to W(CO)6+· during the kiloelectronvolt collisions that occur upon neutralization-reionization (NR) have been estimated based on the relative abundances of the W(CO)0-6+· products present in NR spectra (thermochemical method). The average internal energy of the incipient {W(CO)6+·}* ions arising after near thermoneutral neutralization with trimethylamine followed by reionization with O2 is ∼9 eV for 8-keV precursor ions and is mainly deposited during reionization, For comparison, the mean internal energy of {W(CO)6+·}* after electron ionization (EO or collisionally activated dissociation (CAD) is ∼ 6 eV. Making the neutralization step endothermic slightly increases the overall excitation gained; however, a large increase in endothermicity (> 16 eV) causes only a modest rise of the average internal energy (<2 eV). The P(ε) curve for NR increases exponentially up to ∼ 6 eV and levels off at higher energies.. showing that the probability of imparting large internal energies (6-17 eV) is high. In sharp contrast, the most probable excitation on CAD is ≤6 eV, and the probability of deposition of larger energies declines exponentially. The mean internal energies after CAD and NR decrease steadily when the kinetic energy is lowered. The structure (minima-maxima) observed in the P(ε) distribution for El, which most likely originates from Franck-Condon factors, is not reproduced in the distributions for NR or high energy CAD, despite the fact that all three methods involve electronic excitation. Because of the large internal energies transferred upon NR, NR mass spectrometry could be particularly useful in the differentiation of ionic isomers with high dissociation but low isomerization thresholds.",
author = "Sarka Beranova and Chrys Wesdemiotis",
year = "1994",
month = "1",
day = "1",
doi = "10.1016/1044-0305(94)85070-4",
language = "English (US)",
volume = "5",
pages = "1093--1101",
journal = "Journal of the American Society for Mass Spectrometry",
issn = "1044-0305",
publisher = "Springer New York",
number = "12",

}

TY - JOUR

T1 - Internal energy distributions of tungsten hexacarbonyl ions after neutralization-Reionization

AU - Beranova, Sarka

AU - Wesdemiotis, Chrys

PY - 1994/1/1

Y1 - 1994/1/1

N2 - The internal energy distributions P(ε) transferred to W(CO)6+· during the kiloelectronvolt collisions that occur upon neutralization-reionization (NR) have been estimated based on the relative abundances of the W(CO)0-6+· products present in NR spectra (thermochemical method). The average internal energy of the incipient {W(CO)6+·}* ions arising after near thermoneutral neutralization with trimethylamine followed by reionization with O2 is ∼9 eV for 8-keV precursor ions and is mainly deposited during reionization, For comparison, the mean internal energy of {W(CO)6+·}* after electron ionization (EO or collisionally activated dissociation (CAD) is ∼ 6 eV. Making the neutralization step endothermic slightly increases the overall excitation gained; however, a large increase in endothermicity (> 16 eV) causes only a modest rise of the average internal energy (<2 eV). The P(ε) curve for NR increases exponentially up to ∼ 6 eV and levels off at higher energies.. showing that the probability of imparting large internal energies (6-17 eV) is high. In sharp contrast, the most probable excitation on CAD is ≤6 eV, and the probability of deposition of larger energies declines exponentially. The mean internal energies after CAD and NR decrease steadily when the kinetic energy is lowered. The structure (minima-maxima) observed in the P(ε) distribution for El, which most likely originates from Franck-Condon factors, is not reproduced in the distributions for NR or high energy CAD, despite the fact that all three methods involve electronic excitation. Because of the large internal energies transferred upon NR, NR mass spectrometry could be particularly useful in the differentiation of ionic isomers with high dissociation but low isomerization thresholds.

AB - The internal energy distributions P(ε) transferred to W(CO)6+· during the kiloelectronvolt collisions that occur upon neutralization-reionization (NR) have been estimated based on the relative abundances of the W(CO)0-6+· products present in NR spectra (thermochemical method). The average internal energy of the incipient {W(CO)6+·}* ions arising after near thermoneutral neutralization with trimethylamine followed by reionization with O2 is ∼9 eV for 8-keV precursor ions and is mainly deposited during reionization, For comparison, the mean internal energy of {W(CO)6+·}* after electron ionization (EO or collisionally activated dissociation (CAD) is ∼ 6 eV. Making the neutralization step endothermic slightly increases the overall excitation gained; however, a large increase in endothermicity (> 16 eV) causes only a modest rise of the average internal energy (<2 eV). The P(ε) curve for NR increases exponentially up to ∼ 6 eV and levels off at higher energies.. showing that the probability of imparting large internal energies (6-17 eV) is high. In sharp contrast, the most probable excitation on CAD is ≤6 eV, and the probability of deposition of larger energies declines exponentially. The mean internal energies after CAD and NR decrease steadily when the kinetic energy is lowered. The structure (minima-maxima) observed in the P(ε) distribution for El, which most likely originates from Franck-Condon factors, is not reproduced in the distributions for NR or high energy CAD, despite the fact that all three methods involve electronic excitation. Because of the large internal energies transferred upon NR, NR mass spectrometry could be particularly useful in the differentiation of ionic isomers with high dissociation but low isomerization thresholds.

UR - http://www.scopus.com/inward/record.url?scp=0001376440&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0001376440&partnerID=8YFLogxK

U2 - 10.1016/1044-0305(94)85070-4

DO - 10.1016/1044-0305(94)85070-4

M3 - Article

C2 - 24226515

AN - SCOPUS:0001376440

VL - 5

SP - 1093

EP - 1101

JO - Journal of the American Society for Mass Spectrometry

JF - Journal of the American Society for Mass Spectrometry

SN - 1044-0305

IS - 12

ER -