Strong-field-induced bond rearrangement in CH<sub>3</sub>NCS ions

ORAL

Abstract

The methyl isothiocyanate (MITC) molecule, CH3NCS, a common agricultural pesticide, is of great interest in terms of its health and environmental impacts. We study intense ultrafast laser-induced ionization and fragmentation of this molecule, focusing on the CHnS+ (n=0-3) fragments arising due to bond rearrangement. Methyl thiocyanate (MTC), CH3SCN, is a potential impurity that could also contribute these fragments through bond cleavage. This issue is tackled by interrogating MITC and MTC separately utilizing a femtosecond pump-probe approach to record the time-resolved behavior of the fragment ions. For MITC, we find modulations in the CH3S+ yield at frequencies of about 130 cm-1 and 250 cm-1. CH3S+ from MTC exhibits a markedly different formation time from the case of MITC and also does not show the aforementioned oscillations. To shed light on our findings, we have performed high-level quantum calculations and simulations investigating the role of bending motion in the rearrangement process.

*This work is supported by the U. S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Atomic, Molecular and Optical Sciences Program under Award Number SISGR (DE-SC0002325).

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Presenters

  • Jacob Stamm

    • Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA

Authors

  • Shuai Li

    • Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA

  • Bethany C Jochim

    • Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA
    • Kansas State University

  • Jacob Stamm

    • Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA

  • Stephen Yuwono

    • Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA

  • Piotr Piecuch

    • Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA; Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA

  • James Jackson

    • Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA

  • Marcos Dantus

    • Department of Chemistry, Michigan State University, East Lansing, MI 48824, USA; Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824, USA