Dissociative ionization of ethanol, methanol and butanol molecules

Zavilopulo, A. N.; Chipev, F.F.; Kokhtych, Lyudmyla M.

doi:10.1016/j.nimb.2005.03.126

Cited by 28 publications

(27 citation statements)

References 7 publications

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“…The cation of m/z = 30 amu can be attributed to the formaldehyde ion. Zavilopulo et al [27] and Cummings and Bleakney [28] in addition to those compiled by NIST [32].…”

Section: Methanolmentioning

confidence: 99%

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Electron impact ionisation and fragmentation of methanol and ethanol

Nixon

Pires

Neves

et al. 2016

International Journal of Mass Spectrometry

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Electron impact ionisation and dissociative ionisation of the two smallest primary alcohols have been investigated. A quadrupole mass spectrometer was used, with an internal ionising electron source resulting in an energy resolution of ~ 0.8 eV. The partial ionisation cross sections (PICS) for a number of individual cations have been measured for energies between 10 - 100 eV. The present data compares well with previous results for methanol. Surprisingly, however, this study is the first to report individual PICS for ethanol. The sum of the present PICS for both methanol and ethanol is also compared to the total ionisation cross sections reported in the literature and are found to be in good accord. Additionally, appearance energies have been derived by fitting the Wannier equation to data measured within ~ 2 eV of the cation formation threshold. However, the low energy resolution limits the precision with which these values are able to be determined. This study also establishes the validity of the data collected using the apparatus at Universidade Federal de Juiz de Fora (UFJF) and so provides a solid foundation for further studies of larger alcohols

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“…The cation of m/z = 30 amu can be attributed to the formaldehyde ion. Zavilopulo et al [27] and Cummings and Bleakney [28] in addition to those compiled by NIST [32].…”

Section: Methanolmentioning

confidence: 99%

“…also give relative PICS, for energies less than 30eV [27], as well as reporting appearance energies (AEs). The apparatus employed to measure these values used an electron source with an energy resolution comparable to that of Srivastava et al [20], ~ 0.5 eV, and a monopole mass selector.…”

Section: Introductionmentioning

confidence: 99%

Electron impact ionisation and fragmentation of methanol and ethanol

Nixon

Pires

Neves

et al. 2016

International Journal of Mass Spectrometry

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“…The photodissociation of methanol in the gas phase has been studied experimentally and theoretically in the ultraviolet region by several authors (Shi et al 2002;Tang et al 2002;Zavilopulo 2005). However, despite some photoabsorption studies in the X-ray range (Ishii & Hitchcook 1988;Prince et al 2003;Burton et al 1992) there are few studies focusing on the photodissociation pathways in this photon energy range.…”

Section: Introductionmentioning

confidence: 99%

Photodissociation of organic molecules in star-forming regions

Pilling

Neves

Santos

et al. 2006

A&A

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The presence of methyl alcohol or methanol (CH 3 OH) in several astrophysical environments has been characterized by its high abundance that depends on both the production rate and the destruction rate. In the present work, the photoionization and photodissociation processes of methanol have been experimentally studied, employing soft X-ray photons (100-310 eV) from a toroidal grating monochromator (TGM) beamline of the Brazilian Synchrotron Light Laboratory (LNLS). Mass spectra were obtained using the photoelectron photoion coincidence (PEPICO) method. Kinetic energy distribution and abundances for each ionic fragment have been obtained from the analysis of the corresponding peak shapes in the mass spectra. Absolute photoionization and photodissociation cross sections were also determined. We have found, among the channels leading to ionization, about 11-16% of CH 3 OH survive the soft X-rays photons. This behavior, together with an efficient formation pathways, may be associated with the high column density observed in star-forming regions. The three main photodissociation pathways are represented by COH + (or HCO + ) ion release (with ejection of H 2 + H), the dissociation via C-O bond rupture (with strong charge retention preferentially on the methyl fragment) and the ejection of a single energetic (2-4 eV) proton. Since methanol is very abundant in star forming regions, the produced protons could be an alternative route to molecular hydrogenation or a trigger for secondary dissociation processes or even to promote extra heating of the environment.

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“…The setup, in which monopole mass spectrometer MX 7304A with a mass resolution not worse than ΔM = 1Da was used as an analytic device, is described in detail in [8][9][10]. The beam of the glycerin molecules under investigation was formed with the help of a multichan nel source of effusion type (the molecular concentra tion in the beam was on the order of 10 10 -10 11 cm -3 ) and was directed to the ion source with electron ion ization, which operated in the electron current stabili zation mode and made it possible to obtain the elec tron beams with a fixed energy of 5-90 eV for currents of 0.05-0.5 mA and energy spread ΔE 1/2 = 250 meV, where ΔE is the full width at half maximum of the elec tron energy distribution.…”

Section: Methodsmentioning

confidence: 99%

“…In addition, the initial segments of the ionization curves of some molecules are ana lyzed in [3,8] with the aim to determine from them the appearance potentials of the fragment ions. As regards the study and analysis of the threshold behavior of the fragment ions resulting from dissociative ionization, information for alcohol molecules is scarce [9].…”

Section: Introductionmentioning

confidence: 99%