Magic-number gold clusters have been studied intensely due to their stability and ease of synthesis. Although silver clusters are less stable, their optical properties and low cost are very attractive. The electronic and geometrical shell closings that are used to explain the anomalous abundances of magic-number clusters do not address the long-term stability and decay of these materials, however. Here we use the relative instability of silver clusters to better understand the nature of metal cluster stability. We studied the stability of a family of silver glutathionate magic-number clusters as function of size, electrostatic and chemical environment. Stability was found to be a non-monotonic function of size, with larger clusters decaying into smaller clusters of previously known sizes. The net surface charge was important for stability while charge screening was not, in contrast to DLVO theory. Using these results, new methods for synthesizing specific cluster sizes could be found.

Long-term stability of metal magic-number clusters

245th National Meeting (2013)

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