Spectra of the triply charged ion CS23+ and selectivity in molecular Auger effects

Abstract

Spectra of triply charged carbon disulphide have been obtained by measuring, in coincidence, all three electrons ejected in its formation by photoionization. Measurements of the CS 2 3+ ion in coincidence with the three electrons identify the energy range where stable trications are formed. A sharp peak in this energy range is identified as the 2 ⌸ ground state at 53.1Ϯ 0.1 eV, which is the lowest electronic state according to ab initio molecular orbital calculations. Triple ionization by the double Auger effect is provisionally divided, on the basis of the pattern of energy sharing between the two Auger electrons into contributions from direct and cascade Auger processes. The spectra from the direct double Auger effect via S 2p, S 2s, and C 1s hole states contain several resolved features and show selectivity based on the initial charge localization and on the identity of the initial state. Triple ionization spectra from single Auger decay of S 2p-based core-valence states CS 2 2+show retention of the valence holes in this Auger process. Related ion-electron coincidence measurements give the triple ionization yields and the breakdown patterns in triple photoionization at selected photon energies from 90 eV to above the inner shell edges.

Triple ionization of CO2 by valence and inner shell photoionization

“…The spectrum contains a weak but clear peak at 74 eV followed by broader structures of greater area, the first centred at about 80 eV; the spectrum resembles that of CS +++ 2 acquired recently by the same technique. 32 The width of the 74 eV peak com- pared with the estimated instrumental resolution of 1.5 eV is consistent with population of a single vibrational level in a quasi-stable state.…”

“…32 The lowest energy triple ionization for formation of the nascent [CO 2 ] +++ ion, presumably at about the neutral molecule geometry, is seen in the spectrum of Fig. 9 as a sharp peak at 74 ± 0.5 eV, and in Figs.…”

Ultrafast Charge Transfer of a Valence Double Hole in Glycine Driven Exclusively by Nuclear Motion

“…1 are in good agreement with the calculated spectra of glycine using particle-particle Green's function techniques [39]. Because of the large energy gap of about 15 eV between states dominated by ½ðO2sÞ −2 and ½ðN2sÞ −2 configurations, the electronic and nuclear dynamics initiated from the localized double-hole states at either atomic site can, in principle, be probed with complete knowledge of the initial electronic state of the ion by coincident detection of the energy of the Auger electron [40][41][42][43].…”

Single-photon double and triple ionization of acetaldehyde (ethanal) studied by multi-electron coincidence spectroscopy

“…Both processes are examples of double ionization, where the two electrons emitted may share the excess energy provided by the absorbed photon arbitrarily, in contrast to fixed electron kinetic energies typically observed in cases of single core shell ionization followed by normal Auger decay. This method was successfully expanded to the study of valence triple ionization 27,28 , where the excess photon energy is shared between three emitted electrons, and to the case of double Auger decay 29,30 of a single core vacancy.…”