Zero kinetic energy, pulsed-field ionization spectroscopy of hydrogen iodide

Abstract

The rotationally resolved, zero kinetic energy, pulsed-field ionization (ZEKE-PFI) spectrum of the HI+ X 2Π1/2, v+=0 level, obtained by double-resonance excitation via the HI F 1Δ2, v=0 level, is reported. The rotational and Λ-doubling constants for the HI+ X 2Π1/2, v+=0 level obtained from the experiment are close to those estimated theoretically by Mank et al. [J. Chem. Phys. 95, 1676 (1991)]. At higher pressures, the dissociative charge transfer reaction HI*+HI→HI++H+I− represents a potentially serious loss mechanism for the high Rydberg states that give rise to the ZEKE-PFI signal. This result is of more general applicability, because it provides evidence that collisions of the Rydberg electron with neighboring molecules can play a significant role in ZEKE-PFI experiments.

Two‐Photon Dissociation Spectroscopy of State‐Selected HCl+ and DCl+ Ions

“…The X 2 P ion ground state has been investigated extensively for various halogen hydrides. [21][22][23][24] Kulp described the 2 P state of HCl + as an intermediate between Hund's cases (a) and (d), [1] while Norling discussed a combination of Hund's cases (a) and (b). [4] 6,7,8,9).…”

Using the Phase of Light as a Photochemical Tool

“…The ionization threshold lies at 83750 ( 1 cm -1 , 34,35 and the spin-orbit excited X 2 Π 1/2 state lies at 89109 ( 1 cm -1 . 36 The potential energy curves relevant to this subsection are sketched in Figure 6. Phase lag measurements were performed in the energy regime 84200-85020 cm -1 , which lies slightly above the first ionization threshold.…”

“…Removal of an outer π electron produces the ground state X 2 Π i ion. The ionization threshold lies at 83750 ± 1 cm -1 , , and the spin−orbit excited X 2 Π 1/2 state lies at 89109 ± 1 cm -1 6 Excitation scheme of HI .…”

“…The ground-state ionization potential was calculated by subtracting the spin−orbit splitting reported in ref from the ionization potential of the spin−orbit excited molecule reported in ref .…”

High energy state interactions, energetics and multiphoto-fragmentation processes of HI

“…A large number of Rydberg and ion-pair vibrational states (HI**) have been assigned and characterized both in absorption [21][22][23] and resonance enhanced multiphoton ionization (REMPI) [24][25][26][27][28][29][30] for the excitation energy region of about 66 000-75 000 cm À1 . Photofragmentation processes have been explored by mass resolved REMPI, [24][25][26][27][28][29][30] photoelectron spectra [31][32][33][34][35] and velocity map imaging (VMI) 36,37 studies.…”