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Ultraviolet photodissociation of the N-methylpyridinium ion: action spectroscopy and product characterization

Journal Article


Abstract


  • The ultraviolet photodissociation of gas-phase N-methylpyridinium ions is studied at

    room temperature using laser photodissociation mass spectrometry and structurally

    diagnostic ion-molecule reaction kinetics. The C5H5N-CH3

    + (m/z 94), C5H5N-CD3

    +

    (m/z 97), and C5D5N-CH3

    +(m/z 99) isotopologues are investigated and it is shown that

    the N-methylpyridinium ion photodissociates by the loss of methane in the 36 000 –

    43 000 cm-1 (280 – 230 nm) region. The dissociation likely occurs on the ground state

    surface following internal conversion from the S1 state. For each isotopologue, by

    monitoring the photofragmentation yield as a function of photon wavenumber, a

    broad vibronically-featured band is recorded with origin (0-0) transitions assigned at

    38 130, 38 140 and 38 320 cm-1 for C5H5N-CH3

    + C5H5N-CD3+ and C5D5N-CH3

    +,

    respectively. With the aid of quantum chemical calculations (CASSCF(6,6)/aug-ccpVDZ)

    most of the observed vibronic detail is assigned to two in-plane ring

    deformation modes. Finally, using ion-molecule reactions the methane co-product at

    m/z 78 is confirmed as 2-pyridinylium ion.

Authors


  •   Hansen, Christopher (external author)
  •   Kirk, Benjamin B. (external author)
  •   Blanksby, Stephen J. (external author)
  •   Trevitt, Adam J.

Publication Date


  • 2013

Citation


  • Hansen, C., Kirk, B. B., Blanksby, S. J. & Trevitt, A. J. (2013). Ultraviolet photodissociation of the N-methylpyridinium ion: action spectroscopy and product characterization. The Journal of Physical Chemistry Part A: Molecules, Spectroscopy, Kinetics, Environment and General Theory, 117 (42), 10839-10846.

Scopus Eid


  • 2-s2.0-84886636523

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/1201

Has Global Citation Frequency


Number Of Pages


  • 7

Start Page


  • 10839

End Page


  • 10846

Volume


  • 117

Issue


  • 42

Place Of Publication


  • United States

Abstract


  • The ultraviolet photodissociation of gas-phase N-methylpyridinium ions is studied at

    room temperature using laser photodissociation mass spectrometry and structurally

    diagnostic ion-molecule reaction kinetics. The C5H5N-CH3

    + (m/z 94), C5H5N-CD3

    +

    (m/z 97), and C5D5N-CH3

    +(m/z 99) isotopologues are investigated and it is shown that

    the N-methylpyridinium ion photodissociates by the loss of methane in the 36 000 –

    43 000 cm-1 (280 – 230 nm) region. The dissociation likely occurs on the ground state

    surface following internal conversion from the S1 state. For each isotopologue, by

    monitoring the photofragmentation yield as a function of photon wavenumber, a

    broad vibronically-featured band is recorded with origin (0-0) transitions assigned at

    38 130, 38 140 and 38 320 cm-1 for C5H5N-CH3

    + C5H5N-CD3+ and C5D5N-CH3

    +,

    respectively. With the aid of quantum chemical calculations (CASSCF(6,6)/aug-ccpVDZ)

    most of the observed vibronic detail is assigned to two in-plane ring

    deformation modes. Finally, using ion-molecule reactions the methane co-product at

    m/z 78 is confirmed as 2-pyridinylium ion.

Authors


  •   Hansen, Christopher (external author)
  •   Kirk, Benjamin B. (external author)
  •   Blanksby, Stephen J. (external author)
  •   Trevitt, Adam J.

Publication Date


  • 2013

Citation


  • Hansen, C., Kirk, B. B., Blanksby, S. J. & Trevitt, A. J. (2013). Ultraviolet photodissociation of the N-methylpyridinium ion: action spectroscopy and product characterization. The Journal of Physical Chemistry Part A: Molecules, Spectroscopy, Kinetics, Environment and General Theory, 117 (42), 10839-10846.

Scopus Eid


  • 2-s2.0-84886636523

Ro Metadata Url


  • http://ro.uow.edu.au/smhpapers/1201

Has Global Citation Frequency


Number Of Pages


  • 7

Start Page


  • 10839

End Page


  • 10846

Volume


  • 117

Issue


  • 42

Place Of Publication


  • United States