Year: 2026
Type: preprint
Abstract: We investigate fragmentation and molecular growth induced by keV ions in initially neutral gas-phase adamantane clusters, the simplest diamondoid molecule (Ad, C$_{10}$H$_{16}$). Using time-of-flight mass spectrometry in combination with quantum-chemical calculations, we find that intact cluster cations undergo extensive dehydrogenation. We also observe a distinct distribution of singly charged products with masses predominantly between those of the adamantane monomer and dimer cations. We attribute these species to ion-induced growth products and interpret their formation considering the smallest cluster cation, [Ad]$_2^+$, using quantum-chemical calculations. Our results demonstrate that ionization strongly reorganizes the dimer geometry, facilitating H$_2$ elimination and intermolecular covalent C--C bond formation. Weakly bound adamantane clusters are thereby transformed into covalently bound carbonaceous species with a strong preference for specific molecular structures. These findings provide new insight into ionization-driven molecular growth in saturated hydrocarbon systems contributing to the understanding of molecular complexification, with implications for chemical physics and astrochemistry.
Source: arXiv (Cornell University)
Institutions: Centre National de la Recherche Scientifique, École Nationale Supérieure d'Ingénieurs de Caen, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, Normandie Université, Centre de Recherche sur les Ions, les Matériaux et la Photonique, Université de Caen Normandie, Lund University, University of Gothenburg, Institute of Physical Chemistry, Polish Academy of Sciences
Language: English
Subfield: Spectroscopy
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
Awards: G3992678186, G4005691891, Reactive intermediates in dicationic and higher charge states, Caen Strategy for Advancement in Research, G7080048889, Attosecond electron-nuclear dynamics studied using intense XUV and X-ray laser pulses, Research And Development with Ion Beams – Advancing Technology in Europe
OpenAlex ID: W7214937489