“Antiaromatic compounds” is what chemists call a class of ring molecules which are extremely instable – the opposite of the highly stable aromatic molecules. Because they exist for mere split seconds, they can only be detected by extremely demanding, ultrafast methods. Together with colleagues from Max Planck Institute for Coal Research in Mülheim, researchers from the Cluster of Excellence RESOLV at Ruhr-Universität Bochum have succeeded in isolating the antiaromatic fluorenyl cation at extremely low temperatures in water ice. Thus, they were able to conduct a spectroscopic analysis for the very first time. Their report is published in “Angewandte Chemie”.