Using a simple self-oligomerization process, Daniel Beaudoin, James D. Wuest, and coworkers at the University of Montreal have synthesized a giant carbocycle that is the largest single-molecule hydrocarbon that has ever been crystallized and characterized by X-ray diffraction (Angew. Chem. Int. Ed. 2015, DOI: 10.1002/anie.201509608). Single-molecule compounds containing more carbon atoms have been reported, Beaudoin says, but either they could not be analyzed by X-ray crystallography or they contained metallic atoms in their structure. The new macrocyclic compound is unique not only for its sheer size but also for the strategy used to forge it through the self-assembly of building blocks that couple via reversible C–C covalent bonds. The synthesis of large covalent molecules typically requires templating approaches or laborious, multistep synthetic procedures. The team instead built the molecule by using lithiation to attach fluorenone groups to a spirobifluorenyl core, followed by reductive mercury coupling to link six of those units together to make the supersized macrocyclic hydrocarbon.