Encapsulation of Neutral Gold Nanoclusters by Resorcinarenes

A new strategy for encapsulating neutral nanoclusters is presented which employs surfactants with large concave headgroups and multiple contact sites. Au nanoclusters ranging from 3 to 20 nm in diameter were generated in the vapor phase and dispersed into dilute solutions of resorcinarenes 1 − 3, where they were stabilized for up to several months. The resorcinarenes were readily displaced by dodecanethiol, which resulted in the precipitation of the larger particles as determined by UV−vis absorption spectroscopy and transmission electron microscopy. The chemisorption of resorcinarenes to the Au cluster surface is most likely mediated by multiple Au−O interactions, which is supported by surface-enhanced Raman spectroscopy.