Berlin 2008 – scientific programme
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O: Fachverband Oberflächenphysik
O 28: Symposium: Size-Selected Clusters at Surfaces II
(Invited Speakers: Steven Buratto, Stefan Vajda, Matthias Arenz)
O 28.4: Talk
Tuesday, February 26, 2008, 12:45–13:00, MA 005
Deuteration of mass-selected Cn clusters deposited on HOPG — •Artur Böttcher, Daniel Löffler, Patrick Weis, Manfred Kappes, Angela Bihlmeier, and Wilhelm Klopper — Institut für Physikalische Chemie, Universität Karlsruhe (TH), D-76128 Karlsruhe, Germany
We studied the size-selectivity in the deuteration of carbon clusters, Cn (n=48-70) deposited on HOPG. In contrast to the weakly stabilized molecular solids of classical fullerenes, the non-IPR fullerenes form strongly bound [Cn]m oligomers stabilized by covalent bonds between the non-IPR sites in Cn cages. The deuteration procedure has been performed under ultra high vacuum conditions by exposing the deposited layers to atomic deuterium. The adoption of deuterium atoms raises the inter-cage cohesion of the C60 and C70 films what has been attributed to the formation of D-induced polymeric chains likely comprising covalently interlinked cages. Deuteration of non-IPR films results in considerable weakening of the intercage bonds as revealed by lower sublimation enthalpies found for all CnDx films [1]. DFT calculations indicate a considerable reduction of the inter-cage bonds accompanying the progressing D-adoption. This process ends with D-induced scission of oligomers and formation of weakly interacting CnDx cages. The contrary reaction trends are triggered by the presence of the non-IPR sites which act as decisive reaction centers. The size of the Cn cages appears of minor relevance for the reaction path.
[1] D. Löffler et al. J. Chem. Phys. Smalley Issue(2007)