Multiphoton ionization mechanisms in CH3I and CD3I

Mass resolved MPI spectra of methyl iodide in the 430–490 nm region

“…The study showed that absorption of photons in the wavelength region leads to a competition between non-resonant multiphoton ionization of the parent molecule, absorption of another photon the parent molecule ion dissociated CH 3 Fairbrother et al [9] have studied the photodissociation dynamics of methyl iodide at 333 nm. Their results are analogous to those in [18]. Using 275-315 nm femtosecond laser, Janssen [19] testified the controllable steps: absorption of twophoton energies (three-photon energies in this study) to 6p and 7s Rydberg states and a further absorption of one photon, then the molecule ionized.…”

“…Their studies have confirmed the view that the predominant pathway to ions is from photodissociation followed by ionization of the neutral CH 3 and I photofragment. Over the wavelength range 330 -335 nm, using the mass spectra technology, Garrett [18] have studied the multiphoton ionization of methyl iodide. The study showed that absorption of photons in the wavelength region leads to a competition between non-resonant multiphoton ionization of the parent molecule, absorption of another photon the parent molecule ion dissociated CH 3 Fairbrother et al [9] have studied the photodissociation dynamics of methyl iodide at 333 nm.…”

UV-induced desorption of CH3X (X=I and Br)/TiO2(110)

“…In a previous experiment involving multiphoton ionization of gas-phase CH 3 I, the CH 3 I ϩ ion was only detected at fluences more than two orders magnitude higher than the fluences used in this experiment. 63 Multiple excitations of adsorbates by photogenerated substrate electrons have only been reported for femtosecond pulses, which have ϳ4 orders of magnitude higher peak irradiance than those of nanosecond pulses. 64…”

Multiple ionization of CH3I clusters by nanosecond laser: Electron energy distribution and formation mechanism of multiply charged ions

“…CH 3 I, a symmetric top molecule, has been used extensively to study the ionization and dissociation dynamic process [1][2][3]. Recently, the interaction of nanosecond laser with CH 3 I cluster was investigated widely, where multiply charged ions with high energy were observed experimentally [4][5][6][7].…”