Martin Kuhn

The adsorption of helium atoms on coronene cations

We report the first experimental study of the attachment of multiple foreign atoms to a cationic polycyclic aromatic hydrocarbon (PAH). The chosen PAH was coronene, C24H12, which was added to liquid helium nanodroplets and then subjected to electron bombardment. Using mass spectrometry, coronene cations decorated with helium atoms were clearly seen and the spectrum shows peaks with anomalously high intensities (“magic number” peaks), which represent ion-helium complexes with added stability. The data suggest the formation of a rigid helium layer consisting of 38 helium atoms that completely cover both faces of the coronene ion. Additional magic numbers can be seen for the further addition of 3 and 6 helium atoms, which are thought to attach to the edge of the coronene. The observation of magic numbers for the addition of 38 and 44 helium atoms is in good agreement with a recent path integral Monte Carlo prediction for helium atoms on neutral coronene. An understanding of how atoms and molecules attach to ...

C-60(+) and the Diffuse Interstellar Bands: An Independent Laboratory Check

In 2015, Campbell et al. presented spectroscopic laboratory gas phase data for the fullerene cation,

Building Carbon Bridges on and between Fullerenes in Helium Nanodroplets

{{{\rm{C}}}_{60}}^{+}

Isomeric Broadening of C60+ Electronic Excitation in Helium Droplets: Experiments Meet Theory

, that coincide with the reported astronomical spectra of two diffuse interstellar band (DIB) features at 9633 and 9578 A. In the following year, additional laboratory spectra were linked to three other and weaker DIBs at 9428, 9366, and 9349 A. The laboratory data were obtained using wavelength-dependent photodissociation spectroscopy of small (up to three) He-tagged

Magic Numbers for Packing Adamantane in Helium Droplets: Cluster Cations, Dications, and Trications

{{{\rm{C}}}_{60}}^{+}\mbox{--}{\mathrm{He}}_{n}

Complexes of gold and imidazole formed in helium nanodroplets

ion complexes, yielding rest wavelengths for the bare

Highly Stable [C60AuC60]+/- Dumbbells

{{{\rm{C}}}_{60}}^{+}

Electron-induced chemistry in imidazole clusters embedded in helium nanodroplets

cation by correcting for the He-induced wavelength shifts. Here we present an alternative approach to derive the rest wavelengths of the four most prominent

Cs+ Solvated in Hydrogen—Evidence for Several Distinct Solvation Shells

{{{\rm{C}}}_{60}}^{+}

Atomically resolved phase transition of fullerene cations solvated in helium droplets

absorption features, using high-resolution laser dissociation spectroscopy of