Energy-resolved collision-induced dissociation of Cun+ (n=2–9): Stability and fragmentation pathways

Abstract

Collision induced dissociation of Cun+ clusters (n=2–9) in collision with Xe is presented in the center-of-mass energy range from about 100 meV to above 15 eV. The collision energy dependence is measured for the total and the partial dissociation cross sections, and the dissociation thresholds for the dominating processes are derived. The threshold energies show pronounced odd–even alternations, reflecting a higher stability of the odd-numbered, Cu2n+1+, clusters. Further, the evaporation of a single neutral atom is found to be the energetically favorable process for the even-numbered clusters, while the loss of the neutral dimer is favorable in the case of the odd-numbered clusters. An exception is Cu9+, where the formation of Cun−1+ is energetically favorable, and the energetics of the Cun−2+ formation are in good agreement with sequential evaporation of two neutral monomers. Here we discuss the energy dependency of the total and partial dissociation cross sections, and try to give a consistent picture of the dissociation dynamics. We present binding energies for the cationic clusters from their dissociation thresholds, and use those, in combination with the literature values for the ionization potentials of Cun, to estimate the binding energies for neutral copper clusters. Finally, we compare this work to earlier theoretical calculations, as well as experimental estimations of the binding energies.

Density functional theory investigation of structure, stability, and glycerol/hydrogen adsorption on Cu, CuZn, and CuZnO clusters

“…The density functional theory (DFT) calculations of clusters performed using Gaussian basis sets are also devoid of the artifacts arising from the use of periodic boundary conditions with plane wave basis sets. Finally, as the controlled experimental synthesis of clusters is quite feasible, [ 21–24 ] it is possible to validate the theoretical findings using the experimental data on the same system. One of the successful applications of this approach involves studies of CO oxidation on gold nanoclusters.…”

Decay pathways of small gold clusters

“…Studies of the alkali-metal clusters Li + n (n = 4-42) [1], Na + n (n = 5-40) [2] and K + n (n = 5-200) [3], and of the monovalent noble metal clusters Cu + n (n = 2-17) [5,12], Ag + n (n = 3-21) [4,6] and Au + n (n = 3-23) [7] show that small odd-numbered clusters of these elements evaporate a neutral dimer while the other cluster sizes evaporate neutral monomers. A similar behavior has also been found for anionic clusters, Cu − n (n = 2-8) [10], Ag − n (n = 2-11) [9] and Au − n (n = 2-15) [8,11].…”

“…The fragmentation pathways of singly charged metal clusters have been studied for several monovalent elements [1][2][3][4][5][6][7][8][9][10][11][12] and are an important tool in understanding cluster energetics and dynamics. After moderate excitation above their dissociation threshold singly charged metal cluster ions show a competition between the evaporation of a single neutral atom and a neutral dimer…”

Photodissociation of small group-11 metal cluster ions: Fragmentation pathways and photoabsorption cross sections

“…For most clusters of group-11 metals (copper, silver and gold), neutral monomer evaporation is the only relevant decay pathway. For some cluster sizes, however, neutral dimer evaporation is known to be a strong competitor [1][2][3][4][5][6][7][8][9][10][11][12][13]. This competition can be described in terms of the statistical nature of the unimolecular dissociation process.…”