Building Bridges with Carbon Atoms on and between Fullerenes Serge A. Krasnokutski Friedrich Schiller University of Jena, 07740 Jena, Germany In collaboration with group of Paul Scheier Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria MPI for Astronomy, Königstuhl 17,69117 Heidelberg, Germany

Motivation C60 and C60+ were detected in the ISM in the neutral and ionized form. Estimates show about 1% of all carbon in the form of C60. Cami, J., Bernard-Salas, J., Peeters, E., & Malek, S. E. 2010, Science, 329, 1180 Sellgren, K., Werner, M. W., Ingalls, J. G., et al. 2010, ApJL, 722, L54-L57 Campbell, E. K., Holz, M., Gerlich, D., et al. 2015, Nature, 523, 322-323 According to different estimations, up to 80 % of all carbon in the ISM exists in the form of an atomic gas. Snow, T. P., & Witt, A. N. 1995, Science, 270, 1455-1460 In the ISM, C60 can be exposed to subsequent encounters with carbon atoms and cations. We study the possible consequences of such encounters.

The He droplet experimental setup

Mass spectra recorded for C60Cn+ and C60Cn- ions 22 eV 70 eV Droplets contain C60 and 13C

Symmetric structures computed for C60(C)6 B3LYP/6-31g(d)

Mass spectra recorded for C60Cn+ ions 70 eV 13CC60 13C2C60 13CC60H2O Droplets contain C60, 13C, and H2O

Mass spectra recorded for 12C6013CnHn+ ions for droplets containing C60, 13C, and H2. 70 eV

Mass spectra recorded for C60Cn+/ (C60)2Cn+ ions and C60Cn-/ (C60)2Cn- ions 70 eV 22 eV

Mass spectra recorded for C60Cn+ and C60Cn- ions 22 eV 70 eV Droplets contain C60 and 13C

Stable cations observed in the experiments (C60)nCn-1 C61CN C61CO C61C2H

Conclusions 1. The observed C additions that chemically activate the carbon surface of C60 have important implications. They form a family of novel carbenes that add H2 and H2O, as well as C60, and imply the presence of a novel generation of derivatised fullerene molecules such as C60(C:)n, C60(CH(H))n, C60(CH(OH))n and even C60(C=C60)n in carbon-rich circumstellar and interstellar environments. 2. Other carbene chemistry with other circumstellar/interstellar molecules, such as :CO for example, itself a carbene, would lead to the formation of additional novel molecules, such as C60(C=CO)n with :CO, for example. Spectroscopic searches for such species in interstellar and circumstellar environments might well be fruitful. Further information: S. A. Krasnokutski, M. Kuhn, A. Kaiser, A. Mauracher, M. Renzler, D. K. Bohme, and P. Scheier J. Phys. Chem. Lett. 7 (2016) 1440 STSM by the COST Action CM1401 “Our Astro-Chemical History”