Photoionisation mass spectrometric study of acetylene in the VUV region

Hayaishi, T; Iwata, Suehiro; Sasanuma, Michio; Ishiguro, Eiji; Morioka, Y; Iida, Yoshihiro; Nakamura, Masato

doi:10.1088/0022-3700/15/1/016

Cited by 71 publications

(70 citation statements)

References 19 publications

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“…This is in rather good agreement with previous electron impact works [18,36,47,48]. By photoionization [32] the onset is determined at 18.16 eV. The calculation of the thermodynamical onset for C 2 + production through the reaction (19), i.e.…”

Section: 32supporting

confidence: 90%

“…This is in very good agreement with most of the earlier electron impact and mass spectrometric photoionization experiments reported up-to-date [1]. However, Hayaishi et al [32] and Ono and Ng [33] mention the lowest appearance energy to be 16.8±0.1 eV and 16.79±0.03 eV respectively. Recently ZEKE-PIPECO [34] and threshold PEPICO [35] works agree by measuring an onset at 17.36±0.01 eV and 17.44±0.01 eV.…”

Section: 12supporting

confidence: 89%

“…The electron impact values reported in the literature scatter between 20.0±1.0 eV [47] to 23.1 eV [48]. By photoionization only one determination is reported at 20.7 keV [32]. Initial KE of 50 meV has been measured on CH + and no KE is observed on CD + .…”

Section: The Ch + (Cd + ) Dissociative Ionization Channelmentioning

confidence: 99%

“…In their electron impact work Plessis and Marmet [36] had to amplify the C 2 H + signal by 5000 to observe the onset at 16.7 eV. The main difference between these experiments [32,33,36] is the sample pressure. As mentioned in section 2, the present measurements were performed below 10 -6 Torn In these conditions the C 4 H 2 + signal at m/e = 50 is negligible.…”

Section: 12mentioning

confidence: 99%

“…IE(C 2 H) and D(H-C 2 H) are questionable. The latter has been discussed abundantly in the literature and ranges 5.0 < D(H-C 2 H) ≤ 5.79 eV as determined by thermodynamic cycles [16,38], proton transfer [39,40], dissociative ionization [32,33], and spectroscopy [41][42][43]. One of the most reliable value is obtained by negative ion electron detachment spectroscopy [16], i.e.…”

Section: 12mentioning

confidence: 99%

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How Complex can be the Unimolecular Decomposition of a Simple Molecule? The Case of Acetylene. An Electron Impact and PIPECO Investigation

Locht

Servais

1996

Zeitschrift Für Physikalische Chemie

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The dissociative ionization of C 2 H 2 , C 2 D 2 and C 2 HD is presented in this work. Excepting the H 2 + ion formation, all dissociation channels are thoroughly investigated by electron impact. The translational energy distribution as a function of the impinging electron energy and the appearance energy as a function of the translational energy are measured for all fragment ions. KE versus AE diagrams are obtained and the isotope effect is examined. All observed thresholds are analyzed in detail and dissociation mechanisms are proposed. For the C 2 H + ion, the PIPECO technique has also been used. From these discussions the H-C 2 H, HC≡CH and H-C 2 binding energy values are proposed, i.e. 5.33±0.23eV, 9.83±0.10eV and 5.44±0.40 eV respectively. The fragmentation paths leading to C + , CH 2 + and C 2 + are discussed in terms of dissociation mechanisms involving the transient vinylidene structure of the molecular ion as an intermediate.

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Section: 32supporting

confidence: 90%

Section: 12supporting

confidence: 89%

Section: The Ch + (Cd + ) Dissociative Ionization Channelmentioning

confidence: 99%

Section: 12mentioning

confidence: 99%

Section: 12mentioning

confidence: 99%

See 3 more Smart Citations

How Complex can be the Unimolecular Decomposition of a Simple Molecule? The Case of Acetylene. An Electron Impact and PIPECO Investigation

Locht

Servais

1996

Zeitschrift Für Physikalische Chemie

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Persistence of Iodines and Deformation of Molecular Structure in Highly Charged Diiodoacetylene: Anisotropic Carbon Ion Emission

et al. 2010

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Strong electric fields that are larger than those of valence electrons in molecules shake out many electrons from the molecules.[1] The generation of highly charged molecular ions by femtosecond laser fields followed by a Coulomb explosion [2] prepares charged atoms in close proximity. The ion dynamics have been investigated by covariance mapping, [3] momentum imaging techniques, [4] and simple consideration of kinetic energy releases. The interaction between ionic species is usually solved by a classical equation of motion under point-charge approximation. Supposing that two charges with different masses exist in close proximity, the light ion flies away while the heavy counterion remains near the original location to conserve momentum. If the heavy ion obstacles disturb the direction in which the precursor ion move, the light ions would undergo structural deformation that enables the light ions to fly away. Linear molecules exposed to intense laser fields would provide interesting information on this issue, especially when the terminal heavy atoms block the movement of lighter ions or ion clusters in the linear molecule. We demonstrate the mass effects on the Coulomb explosion processes of acetylene derivatives of similar geometry but with different electronic orbitals and weights of terminal atoms.We compare the Coulomb explosion dynamics between acetylene and diiodoacetylene (DIA, IÀCCÀI). Multiple ionization was carried out with a 40 fs pulse centered at 800 nm, and the ions were detected by a time-of-flight mass spectrometer. Figure 1 shows the time-of-flight mass spectrum of DIA. The principal ions were C 2 I 2 w + (w = 1À4), C 2

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Probing the pyrolysis of ethyl formate in the dilute gas phase by synchrotron radiation and theory

et al. 2023

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The thermal decomposition of the atmospheric constituent ethyl formate was studied by coupling flash pyrolysis with imaging photoelectron photoion coincidence (iPEPICO) spectroscopy using synchrotron vacuum ultraviolet (VUV) radiation at the Swiss Light Source (SLS). iPEPICO allows photoion mass-selected threshold photoelectron spectra (ms-TPES) to be obtained for pyrolysis products. By threshold photoionization and ion imaging, parent ions of neutral pyrolysis products and dissociative photoionization products could be distinguished, and multiple spectral carriers could be identified in several ms-TPES. The TPES and mass-selected TPES for ethyl formate are reported for the first time and appear to correspond to ionization of the lowest energy conformer having a cis (eclipsed) configuration of the O=C(H)-O-C(H 2 )-CH 3 and trans (staggered) configuration of the O=C(H)-O-C(H 2 )-CH 3 dihedral angles. We observed the following ethyl formate pyrolysis products: CH 3 CH 2 OH, CH 3 CHO, C 2 H 6 , C 2 H 4 , HC(O) OH, CH 2 O, CO 2 , and CO, with HC(O)OH and C 2 H 4 pyrolyzing further, forming CO + H 2 O and C 2 H 2 + H 2 . The reaction paths and energetics leading to these products, together with the products of two homolytic bond cleavage reactions, CH 3 CH 2 O + CHO and CH 3 CH 2 + HC(O)O, were studied computationally at the M06-2X-GD3/ aug-cc-pVTZ and SVECV-f12 levels of theory, complemented by further theoretical methods for comparison. The calculated reaction pathways were used to derive Arrhenius parameters for each reaction. The reaction rate constants and branching ratios are discussed in terms of the residence time and newly suggest carbon monoxide as a competitive primary fragmentation product at high temperatures.

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Photoionisation mass spectrometric study of acetylene in the VUV region

Cited by 71 publications

References 19 publications

How Complex can be the Unimolecular Decomposition of a Simple Molecule? The Case of Acetylene. An Electron Impact and PIPECO Investigation

How Complex can be the Unimolecular Decomposition of a Simple Molecule? The Case of Acetylene. An Electron Impact and PIPECO Investigation

Persistence of Iodines and Deformation of Molecular Structure in Highly Charged Diiodoacetylene: Anisotropic Carbon Ion Emission

Probing the pyrolysis of ethyl formate in the dilute gas phase by synchrotron radiation and theory

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