The Multiphoton Ionization Spectrum of Methyl Iodide Revisited: 1.67-2.2 ev Excitation

Authors

  • Debra Jo Scardino Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677, USA
  • Matthew D. McDowell Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677, USA
  • Jacob D. Graham Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677, USA
  • Nathan I. Hammer Department of Chemistry and Biochemistry, University of Mississippi, University, MS 38677, USA

DOI:

https://doi.org/10.4208/jams.010511.011411a

Keywords:

methyl iodide, multiphoton ionization, photofragmentation, photoionization, mass spectra.

Abstract

The study of the multiphoton ionization of methyl iodide has a long and storied history. Here, we revisit this topic and present spectra of each of the photoionization and photodissociation fragments ($C^{+},$ $CH^{+},$ $CH_{2}^{+},$ $CH_{3}^{+},$ $CH_{3}I^{+},$ and $I^{+}$) using a custom time-of-flight mass spectrometer and a tunable dye laser over the excitation range of 550-740 nm (2.2-1.67 eV). The choice of this wavelength range allows for excitation through the $A$ state and resonant ionization through higher energy levels using 4+1, 5+1, or 6+1 photons for excitation and ionization.  Although the various fragments yield very similar spectra, fewer fragment ions are observed with increasing wavelength.

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Published

2021-02-23

Issue

Vol. 2 No. 2 (2011)

Section

Articles