Dissociation channels of multiply charged van der Waals clusters

Coulomb fission in multiply charged molecular clusters: Experiment and theory

“…11 If fission results in just two fragments, then the Coulomb repulsion that accompanies their separation should lead to a significant release of kinetic energy, and estimates from previous experiments range from 0.2 to 1 eV. 1,6,7,13 However, it has been shown earlier that a simple point charge calculation of the kinetic energy release expected for a dication cluster composed of a dielectric material gives a very unrealistic estimate for the location of the two charges. 11 Apart from earlier studies of triply charged CO2 and NH3 clusters, 1,8 neither of which included any size-dependent data, there have been no recorded examples of the delayed Coulomb fission of multiply charged molecular clusters.…”

“…1,6,7,13 However, it has been shown earlier that a simple point charge calculation of the kinetic energy release expected for a dication cluster composed of a dielectric material gives a very unrealistic estimate for the location of the two charges. 11 Apart from earlier studies of triply charged CO2 and NH3 clusters, 1,8 neither of which included any size-dependent data, there have been no recorded examples of the delayed Coulomb fission of multiply charged molecular clusters. For doubly charged clusters, the failure to observe Coulomb fission has been attributed to a presence of compression modes, 1,14 which when excited by Coulomb repulsion can dissipate large amounts of energy from a cluster via monomer evaporation.…”

“…11 Apart from earlier studies of triply charged CO2 and NH3 clusters, 1,8 neither of which included any size-dependent data, there have been no recorded examples of the delayed Coulomb fission of multiply charged molecular clusters. For doubly charged clusters, the failure to observe Coulomb fission has been attributed to a presence of compression modes, 1,14 which when excited by Coulomb repulsion can dissipate large amounts of energy from a cluster via monomer evaporation. A previous study of the collision-induced fragmentation of triply charged benzene clusters showed that excitation promoted charge separation, which was accompanied by extensive neutral molecule loss .…”

“…[1][2][3][4][5][6][7] To date, those multiply charged molecular clusters that have been the subject of experimental measurement have exhibited a lower size limit, below which they become unstable due to Coulomb repulsion between the resident charges. 1 There have been numerous experimental attempts to observe the process of Coulomb fission that should accompany the instability of molecular clusters, 1,4,5,6,8 and although charge separation has been observed in photoexcited multiply charged clusters of metal atoms, 9 until recently, 10,11 attempts to observe similar processes in size-selected molecular clusters have not been particularly successful. Last, Jortner and coworkers have complemented the experimental work through their predictions of the fission pathways for highly charged atomic and molecular clusters.…”

“…12 Experiments on multiply charged clusters, have devoted considerable attention to identifying patterns of behaviour that might prevail at or close to ncr. 1,4,5,6,8 However, associated with the magnitude of X has to be a timescale over which an appropriate experiment might distinguish between the two extremes of behaviour. Given the timescales on which many typical mass spectrometers operate (~ 10 -5 s), fission is the most obvious outcome; however, until recently a definitive identification of such a process in a size-selected cluster had not been forthcoming.…”