A versatile setup for studying size and charge-state selected polyanionic nanoparticles

Using the example of metal clusters, an experimental setup and procedure is presented, which allows for the generation of size and charge-state selected polyanions from monoanions in a molecular beam. As a characteristic feature of this modular setup, the further charging process via sequential electron attachment within a three-state digital trap takes place after mass-selection. In contrast to other approaches, the rf-based concept permits access to heavy particles. The procedure is highly flexible with respect to the preparation process and potentially suitable for a wide variety of anionic species. By adjusting the storage conditions, i.e., the radio frequency, to the change in the mass-to-charge ratio, we succeeded in producing clusters in highly negative charge states, i.e., Ag-800(7-). The capabilities of the setup are demonstrated by experiments extracting electronic and optical properties of polyanionic metal clusters by analyzing the corresponding photoelectron spectra. Published under an exclusive license by AIP Publishing.

Automated summary

This study presents an experimental setup and procedure for generating size and charge-state selected polyanions from monoanions using metal clusters as an example. The setup allows for the further charging process via sequential electron attachment, and the rf-based concept permits access to heavy particles. The capabilities of the setup are demonstrated by analyzing the electronic and optical properties of polyanionic metal clusters.