1. Building Bridges with Carbon Atoms on and between Fullerenes
Serge A. Krasnokutski
Friedrich Schiller University of Jena, 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

2. 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,
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,
In the ISM, C60 can be exposed to subsequent encounters with carbon atoms and cations.
We study the possible consequences of such encounters.

3. The He droplet experimental setup

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

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

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

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

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

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

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

11. 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”