10  ZEKE spectroscopy: Into the new millennium

Zero electron kinetic energy spectroscopy of the para-fluorotoluene cation

“…The energies of the excited electronic and cationic states of substituted aromatics make them particularly amenable to one-or two-color photoelectron studies. ZEKE spectroscopy has been applied to a wide range of systems, 12,13 including halogen-substituted benzenes and toluenes. pFT itself has been the subject of both a ZEKE spectroscopic study 14 by Takazawa et al and the sister technique of mass-analyzed threshold ionization ͑MATI͒ spectroscopy by Georgiev et al 3 The former study concentrated on the torsional energy levels of pFT + in its D 0 state, while the latter was mostly concerned with the pFT + -Ar complex.…”

Rovibronic photoionization dynamics of asymmetric-top molecules

“…The investigation of the rovibronic photoionization dynamics of a wide range of polyatomic molecules by photoelectron spectroscopic methods has become possible with the development of pulsed-field-ionization zero-kineticenergy (PFI-ZEKE) photoelectron spectroscopy [10][11][12][13][14][15][16][17]. In conventional photoelectron spectroscopy, the molecules are ionized with radiation of a fixed frequency and the photoelectron kinetic energy, which corresponds to the difference between the photon energy and the internal energy of the cationic core, is measured [18].…”

Experimental techniques and terminology in gas‐phase ion spectroscopy

“…However, it can be possible to use intermediate electronically excited states to overcome this ionization threshold energy. Low‐lying Rydberg states can be used as such intermediates giving rise to numerous specific spectroscopic techniques such as zero electron kinetic energy (ZEKE) spectroscopy and mass‐analyzed threshold ionization (MATI) spectroscopy, as well as their derivatives 44,45 . These techniques lie beyond the scope of the current review.…”