The Adhesion of AgI Molecules to Gaseous Metallic Silver Cluster Cations
Abstract
The evaporative channels for the unimolecular dissociation of metastable AgXlY+ (X = 5-25; Y = 0-4) clusters made by fast atom bombardment of silver foil in the presence of CH3I vapor are observed in the first field free region of a double focussing mass spectrometer. We found three dominant neutral evaporative channels: Ag loss, Ag2 loss and AgI loss. Only Agl2I3+ is found to have an additional channel involving an (AgI)3 loss. Consistent with our previous studies of stable AgXlY+ clusters, we assume a structural formula of (AgX-Y)+(AgI)Y where the metallic part of the cluster conforms to Jellium model predictions. In comparing the relative evaporative loss of AgI from these metastable clusters, we observe: (a) evidence for significant AgI-AgI interaction for clusters whose metallic part has a ls2, IP2 or Is2,Ip4 Jellium configuration; (b) a near constant fractional loss of AgI as the number of AgI units in the parent cluster increases for clusters whose metallic part has a closed main Jellium shell; (c) a relative increase in the fraction loss of Agl as the number of AgI molecules in the parent cluster increases for clusters with an open shell configuration for the metallic part. These observations are discussed in terms of evaporative loss of AgI from structures in which the AgI molecules solvate the metallic part of the cluster. It is proposed that the heat of AgI evaporation is greatly determined by dipole/induced-dipole interactions between the permanent dipole of AgI and the polarizable delocalized electron density of the metallic part of the cluster.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 06, 1993
- Accession Number
- ADA264820
Entities
People
- Clifton K. Fagerquist
- Dilip K. Sensharma
- Mostafa El-Sayed
- Temer S. Ahmadi
Organizations
- University of California, Los Angeles