Carbon dioxide ion dissociations after inner shell excitation and ionization: The origin of site-specific effects

Abstract

Carbon dioxide ion dissociations after inner shell excitation and ionization: The origin of sitespecific effects. Physics, 140(18) Multi-coincidence experiments with detection of both electrons and ions from decay of core-excited and core-ionized states of CO 2 confirm that O 2 + is formed specifically in Auger decay from the C1s-π * and O1s-π * resonances. Molecular rearrangement occurs by bending in the resonant states, and O 2 + is produced by both single and double Auger decay. It is suggested that electron capture by C + after partial dissociation in the doubly ionized core of excited CO 2 + , formed by shake-up in spectator resonant Auger decay, accounts for high kinetic energy and high internal energy in some C + O 2 + fragments. Journal of Chemical

Strong-field-induced bond rearrangement in triatomic molecules

“…A theme throughout previous studies of bond rearrangement [8,11,14,22,23,[26][27][28][39][40][41][42] has been that the primary initiating step is the stimulation of bending modes in the triatomic molecule. With this background, it is not surprising that the bent water molecule has the highest bond rearrangement branching ratio of the molecules examined in this study.…”

“…as well as various photoionization studies[40, 41, 69-74, 87, 88].Several of these studies have noted the production of O + 2 fragments[26,27,40,41], although we are not aware of any reports of the branching ratio. The results of our double ionization branching ratio measurement for CO 2 are reported in TableIII.Two recent strong-field studies of CO 2 report the observation of the CO 2 + nω → O + 2 + C + process induced with laser pulses centered near 800 nm[26,27].…”

“…Despite the increasing attention devoted to these processes, so far most studies have focused on a single molecular species and have occurred under an assortment of experimental conditions. For example, the initiating ioniza-tion mechanism in previous bond rearrangement studies has variously included single [8,11,[37][38][39][40][41][42] and multiple photons [5,22,26,27,43] as well as electron [23,28,44] and heavy ion impact [2,7,30]. To assist in understanding these dynamics we examine bond rearrangement following ultrafast strong-field double ionization of three triatomic molecules: carbon dioxide, carbonyl sulfide and water.…”

Doubly ionized OCS bond rearrangement upon fragmentation – experiment and theory

“…The minor channel producing the SO + + C + ion pair was reported by Wang and Vidal 19 in 2003 using electron impact ionization, and was observed again in 2019 by Zhao et al 31 using strong field ionization. This ion pair can be formed only after bond rearrangement or by extreme bending of the molecules, as happens in CO 2 yielding O 2 + by Auger decay at the main long-lived π* pre-edge resonances 47–49 or after intramolecular isomerization upon double ionization as evidenced for SO 2 producing an O 2 + + S + pair. 50 Interestingly, Zhao et al observed that under strong field ionization conditions the angular distributions of CO + + S + and SO + + C + share the same behavior.…”

Fragmentation Dynamics of a Carbon Dioxide Dication Produced by Ion Impact

“…In comparison, the potential barrier of the CO + + O + channel is 1.00 eV. Meanwhile, for the isomerization channel C + + , Eland et al indicated that the minimum internal energy of 40.80 eV is required. Combining our calculation of the vertical ionization energy of , the potential energy barrier of the C + + channel is about 1.96 eV.…”