TY - JOUR T1 - The Multiphoton Ionization Spectrum of Methyl Iodide Revisited: 1.67-2.2 ev Excitation AU - Scardino , Debra Jo AU - McDowell , Matthew D. AU - Graham , Jacob D. AU - Hammer , Nathan I. JO - Journal of Atomic and Molecular Sciences VL - 2 SP - 93 EP - 98 PY - 2011 DA - 2011/02 SN - 2 DO - http://doi.org/10.4208/jams.010511.011411a UR - https://global-sci.org/intro/article_detail/jams/8114.html KW - methyl iodide, multiphoton ionization, photofragmentation, photoionization, mass spectra. AB -

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.