Access to the published version may require subscription. When citing this work, please cite the original published paper. Preprint This document is the unedited Author’s version of a Submitted Work that was subsequently accepted for publication in after peer review. To access the final edited and published work see: ACS Nano Shantanu Mishra, Thorsten G. Lohr, Carlo A. Pignedoli, Junzhi Liu, Reinhard Berger, José I. Urgel, Klaus Müllen, Xinliang Feng, Pascal Ruffieux, and Roman Fasel Tailoring Bond Topologies in Open-Shell Graphene Nanostructures ACS Nano, Article ASAP DOI: 10.1021/acsnano.8b07225 (2018) https://pubs.acs.org/doi/10.1021/acsnano.8b07225