Limited coordination number and competitive coordination in ammonia–water mixed-ligand complexes of monopositive metal ions as studied by the laser-ablation–molecular beam method: Experiment and simulation

Abstract

Articles you may be interested inMolecular-dynamics simulations of alkaline-earth metal cations in water by atom-bond electronegativity equalization method fused into molecular mechanics

Dynamics of Solvation-Induced Structural Transitions in Mesoscopic Binary Clusters

“…Incidently, the much larger magnitude of DE b for water (see Ref. [1]) is consistent with the fact that water molecule evaporation was rarely observed. Note that the computed value of DS y ͞k B ഠ 12 is quite close to the vaporization entropy of pure ammonia under normal conditions, DS vap ͞k B 11.7, a fact that would suggest that the presence of the ion does not introduce a significant change in the entropy of the mesoscopic ammonia phase, compared to the bulk value.…”

“…-c Ion solvation dynamics in bulk liquids has been the topic of experimental and theoretical studies for many years and its analog in molecular clusters has attracted attention more recently. The availability of new experimental information [1][2][3] as well as the fact that mesoscale molecular clusters have properties distinct from both few-molecule clusters and bulk fluids have contributed to interest in this area. In this Letter we examine the mechanisms that govern the solvation dynamics that occurs after a metal ion collides with a binary polar molecule cluster.…”

“…Even in the absence of a solute, such binary clusters may exhibit a number of equally interesting competitive effects, such as superficial vs bulk states and total segregation vs full mixing, depending on the specific details of the Hamiltonian and the relative concentration of the components [4,5]. Recent molecular beam experiments on singly charged metal ions dissolved in water-ammonia clusters [1] lead one to ask how the ionic solute is incorporated in the originally neutral cluster and what morphological changes of the aggregate take place as the solvation proceeds [6]. We show that the solvation dynamics has two different relaxation contributions: (i) the selective ionic solvation by one component leads to a significant morphological change in the overall cluster structure and (ii) selective cluster evaporation, which presents features distinct from that in simpler clusters.…”

Product Energy and Angular Momentum Partitioning in the Unimolecular Dissociation Of Aluminum Clusters

“…23,25 The advantage of the Klots evaporative ensemble approach over the Engelking model is that both cluster heat capacities and binding energies can be determined with no adjustable parameter. Klots theory has been used for a wide variety of applications, such as the (statistical) modeling of the competitive coordination of different solvent molecules in mixed ligand-metal complexes, 26 and to estimate cluster temperatures or internal energies. 27 In previous work, classical trajectory simulations were used to study the unimolecular dissociations dynamics of the aluminum clusters Al n , n ) 3,6,13.…”

“…The other statistical family of models used to extract structural information from the experimental translational energy for metastable cluster dissociation is based on the Klots theory of cluster evaporation. − This model was applied with some success to a number of clusters, including (H 2 O) n H + clusters 10 and {(NH 3 ) n CH 3 CN}H + and (NH 3 ) n H + clusters. , The advantage of the Klots evaporative ensemble approach over the Engelking model is that both cluster heat capacities and binding energies can be determined with no adjustable parameter. Klots theory has been used for a wide variety of applications, such as the (statistical) modeling of the competitive coordination of different solvent molecules in mixed ligand−metal complexes, and to estimate cluster temperatures or internal energies …”