Clusters dissociation dynamics

Using photoelectron detection in a femtochemistry arrangement, we studied size-selected clusters of ionic systems, covering the transition from gas phase to condensed phase dynamics [6]. We investigated the solvent effect on Oj dissociation dynamics, and observed... 

Until now, most studies of dissociation dynamics of metastable cluster ions have been made using a double-focusing mass spectrometry method (Lifshitz et al. 1990 Lifshitz and Louage 1989, 1990 Stace 1986). As discussed herein, the novel technique of reflectron time-of-flight mass spectrometry is a valuable alternative approach to more standard methods. With carefully designed experiments, it is possible to derive both kinetic energy releases and decay fractions for... 

I trust that this book gives the flavor of the pace, excitement, and accomplishments of the last few years of cluster research. For me, the most surprising and important feature of this volume is the breadth that this new area of physical chemistry demonstrates. The various experimental chapters cover ionic chemistry, hot atom chemistry, photochemistry, neutral molecule chemistry, electron and proton transfer chemistry, chemistry of radicals and other transient species, and vibrational dynamics and cluster dissociation. Of at least equal importance is that theoretical potential energy surface studies are not accessible for cluster systems and are being pursued. All of us associated with this project have tried to convey the fresh insights and contributions that van der Waals cluster research has brought to physical chemistry. 

Dissociation Dynamics of Diatomic Molecules Embedded in Impact Heated Rare Gas Clusters, T. Raz, I. Schek, M. Ben-Nun, U. Even, J- Jortner and R. D. Levine, J. Chem. Phys. 101, 8606 (1994). 

The dissociation of weakly bound van der Waals complexes is a special case of unimolecular dissociation [20]. Because of the exceedingly weak coupling between the dissociation coordinate and the mode (or modes) initially excited, and the very low density of states of the energized complex, narrow resonances are the dominant features of van der Waals spectra. There are, of course, many similarities between the dynamics of physically bound and chemically bound molecules. The dissociation dynamics of these special molecules (or clusters) has been studied in great detail, both experimentally and theoretically. Exhaustive review articles are available [85-89] and therefore van der Waals molecules will not be particularly considered in this chapter. However, one must keep in mind that, as the density of states of van der Waals molecules increases, their dynamics becomes more and more comparable with the dynamics of strongly bound molecules [90,91]. 

DYNAMICS AND ENERGY RELEASE IN BENZENE/AR-CLUSTER DISSOCIATION... 

Bemshtein, V. and Oref, I. (2000) Dynamics and energy release in benzene/Ar cluster-dissociation, J. Chem. Phys.. 112. 686-697. 

Taking M7 cluster as an illustrative example, we have reviewed a novel statistical property of isomerization dynamics in the liquid-like phase, which is a prototype of the high-energy multichannel chemical reaction. We project that studies of chemical reaction will be more and more aiming at such multichannel reactions as dissociation dynamics in electron plasma. 

Using photoelectron detection in a femtochemistry arrangement, we studied size-selected clusters of ionic systems, covering the transition from gas phase to condensed phase dynamics [6]. We investigated the solvent effect on Oj dissociation dynamics, and observed that the addition of one solvent (O2, N2, Xe or N2O) gives very different effects on the dynamics of the nuclear motion, whose wave packet bifurcates in two channels. These real time studies of the one-solvent dynamics provide the time scale of the distinctive processes of electron recombination and bond rupture, and vibrational predissociation— with both... 

Two models for analyte ion formation have been proposed. The older model -which had not had a well-defined name before 2013 and is now proclaimed as Coupled Physical and Chemical Dynamics (CPCD) model - assumes neutral analyte molecules in the expanding plume - regardless of whether the analytes were incorporated in the matrix crystals as neutral species or were quantitatively neutralized by their counterions upon cluster dissociation in the case of precharged incorporated analyte molecules. Subsequent to photoionization of the matrix (Eqs 1.3 and 1.4) and secondary intermolecular matrix reactions leading to the generation of protonated as well as deprotonated matrix ions (Eqs 1.5 and 1.6)... 

Clusters of neutral iodine molecules, I2, in argon can be produced in a molecular beam. The average size of the clusters formed can be adjusted in the range of 40 to 150 argon atoms, as a function of backing pressure, at an average temperature of 30 K or less. The real time dynamics of cluster dissociation has been studied by Zewail and coworkers (Zewail, 1995). The dissociation of the I2 within the cluster is induced by a femtosecond laser pulse, which prepares a wave packet, either... 

To date, neural network potentials have been most frequently applied to represent low-dimensional, molecular PESs. Apart from the central role of molecules in chemistry the main reason for this is certainly the comparably simple mapping of the reference points using electronic structure methods. Low-dimensional NN PESs have been constructed for example for the of ground state and excited state PESs and transition dipole moments of the HCl" ion, " for the OH radical in order to calculate the vibrational levels,for Hi " to calculate rovibrational spectra,for the free H2O molecule, for the dissociation of a Si02 molecule, for the HOOH molecule, for the NOCl molecule, for formaldehyde, for the cis-trans isomerization and dissociation dynamics of nitrous add, " for H + HBr, " for the reaction 0H + H2 H20 + H, for the reaction BeH + H2->BeH2 + H, " for small silicon clusters, " for vinyl bromide, to describe the three-body interaction energies in the H2O-... 

Baer T, Booze j and Weitzei KM (1991) Photoelectron-photoion coincidence studies of ion dissociation dynamics. In Ng CY (ed). Vacuum Ultraviolet Photoionization and Photodissociation of Molecules and Clusters. Singapore World Scientific. 

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