Shining Light on Chiral Monolayer-protected Metal Clusters.

Monolayer-protected metal clusters in the size range between about 10 to 300 metal atoms are a special class of materials with strongly size-dependent behaviour, which is mainly ascribed to discrete electronic energy levels. It was observed that certain sizes of metal clusters show exceptional stability, whereas others are only formed under special conditions, as minor species or not at all. The field has made tremendous progress in the last two decades both in terms of the discovery of new clusters and the understanding of their properties. The focus of this article is on the chirality of these nano-objects and the use of chiroptical spectroscopy to probe their properties.