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Discusses an experimental and theoretical study of the spin-orbit interaction for carbon dioxide and oxygen. Rotationally resolved pulsed field ionization photoelectron (PFI-PE); Angular momentum coupling factor for the photoionization of the present carbon dioxide system.

Studies rotationally resolved pulsed filed ionization photoelectron (PFI-PE) spectra of NO at a specific energy range covering ionization transitions. PFI-PE bands for NO that represent the first rotationally resolved spectroscopic data for these states; Increase in inelastic cross sections for collisions.

Abstract: Recent developments of two-color infrared (IR)-vacuum ultraviolet (VUV) and VUV-IR photoionization and photoelectron detection schemes for spectroscopic studies are described. By preparing molecules in selected rovibrational states by IR excitation prior to VUV-photoionization, state-selected and state-to-state photoionization cross sections can be obtained by IR-VUV-photoionization efficiency (IR-VUV-PIE) and IR-VUV-pulsed field ionization-photoelectron (IR-VUV-PFI-PE) measurements, respectively. Rotationally resolved autoionizing Rydberg states converging to excited ionic states, which cannot be observed by single-photon VUV-PIE measurements, can be examined by the IR-VUV-PIE scheme. By monitoring the photoion and the PFI-PE intensities at a fixed VUV energy as a function of IR frequency, the respective IR photoion and IR absorption spectra of the corresponding neutral molecule can be measured. Two-color VUV-IR photo-induced Rydberg ionization (PIRI) experiment, in which high-n Rydberg states are prepared by VUV-photoexcitation followed by IR-induced autoionization, has also been demonstrated. Since the IR-VUV-PIE, IR-VUV-PFI-PE, and VUV-IR-PIRI methods do not require the existence of a bound intermediate electronic state in the UV and are generally applicable to all molecules, the development of these two-color photoionization and photoelectron schemes is expected to significantly enhance the scope of VUV spectroscopy and chemistry. [Copyright &y& Elsevier]

The vacuum ultraviolet pulsed field ionization-photoelectron (PFI-PE) spectra for CO[sub 2] have been measured in the energy range of 13.6-14.7 eV, revealing complex vibronic structures for the ground CO[sub 2][sup +](X [sup 2]Π[sub g]) state. Many vibronic bands for CO[sub 2][sup +](X [sup 2]Π[sub g]), which were not resolved in previous photoelectron studies, are identified in the present measurement based on comparison with available optical data and theoretical predictions. As observed in the HeI photoelectron spectrum of CO[sub 2], the PFI-PE spectrum is dominated by the symmetry allowed ν[sub 1][sup +] (symmetric stretch) vibrational progression for CO[sub 2][sup +](X [sup 2]Π[sub g]). However, PFI-PE vibronic bands due to excitation of the symmetry disallowed ν[sub 2][sup +] (bending) and ν[sub 3][sup +] (asymmetric stretch) modes with both odd quanta, together with the symmetry allowed even quanta excitations, are clearly discernible. The simulation of rotational contours resolved in PFI-PE vibronic bands associated with excitation to the (ν[sub 1][sup +]=0-1, ν[sub 2][sup +]=0-2, ν[sub 3][sup +]=0) vibrational levels has yielded accurate ionization energies for the formation of these vibronic states from CO[sub 2](X [sup 1]Σ[sub g][sup +]). © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

We have examined the titled reaction near its threshold using the pulsed field ionization photoelectron–photoion coincidence method. The measured 0 K threshold (18.220±0.002 eV) has made possible the determination of more precise values for the 0 K bond dissociation energies for D–OD+ (5.584±0.002 eV) and D–OD (5.191±0.002 eV) and the 0 K heats of formation (ΔH0f0''s) for OD+ (308.83±0.05 kcal/mol) and OD (8.38±0.05 kcal/mol). We found that the available energetic data for the OD/OD+ and D2O/D2O+ system are in excellent agreement with those for the OH/OH+ and H2O/H2O+ system after taking into account the zero-point vibration energies of these species. [Copyright &y& Elsevier]