Ionization dynamics of the branched water cluster: A long-lived non-proton-transferred intermediate

Abstract

a b s t r a c tThe proton transfer (PT) reaction after water cluster ionization is known to be a very fast process occurring on the 10-30 fs time scale. In the present study, the ionization dynamics of the branched water tetramer (H 2 O) 4 were investigated by means of a direct ab initio molecular dynamics (AIMD) method to elucidate the time scale of PT in the water cluster cation. A long-lived non-proton-transferred intermediate was found to exist after the ionization of the branched-type water cluster. The lifetimes of the intermediate were calculated to be ca. 100-150 fs. PT occurred after the formation of the intermediate. The structure of the intermediate was composed of a symmetric cation core: H 2 O-H 2 O + -H 2 O. The broken symmetry of the structure led to PT from the intermediate. The reaction mechanism is discussed based on the theoretical results.

Ion–Radical Pair Separation in Larger Oxidized Water Clusters, (H2O)+n=6–21

“…These structures, sitting 10.3–12.2 kcal/mol above the energy of 6A, constitute the highest-energy class of isomers found and would likely exhibit particularly unique vibrational spectra. Though these species could putatively be involved in the initial ionization dynamics , and have been implicated in recent MD analysesthey are likely too high in energy to be relevant for the present analysis. The fact that they are stable isomers, however, highlights the varied electronic landscape that the sampling procedure must be able to access in larger clusters.…”

Direct ab initio molecular dynamics study on the reactions of multi-valence ionized states of water dimer

“…Svoboda [26,27]. A series of studies on the ionization dynamics of water clusters have also been reported by our group [28][29][30][31][32][33][34]. The time-scale of ionization processes, e.g.…”

“…Svoboda [26,27]. A series of studies on the ionization dynamics of water clusters have also been reported by our group [28][29][30][31][32][33][34]. The time-scale of ionization processes, e.g., the lifetime of reaction intermediates and proton transfer rate in ionized clusters, has been evaluated in previous studies.…”

Infrared spectroscopy of [H2O–Xn]+(n= 1–3, X = N2, CO2, CO, and N2O) radical cation clusters: competition between hydrogen bond and hemibond formation of the water radical cation

“…, the (H 2 O) n + cluster, has been actively studied as the simplest model for ionization of water. 21–23,50–89 Some early theoretical calculations showed that the hemibond formation is preferred. However, many recent high-level theoretical computations agree well that the hemibonded form is less stable than the H-bonded form.…”