The aromatic π-sextet

In organic chemistry, the Clar's aromatic sextet is a simple, intuitive and useful concept for structure analysis and properties prediction of polycyclic aromatic hydrocarbons (PAHs). Nevertheless, despite its over 50 years history, its usage has not been automated yet. This release bridges this obvious gap by delivering an interactive constructor of PAHs, including non-benzenoid ones, which may feature pentagonal or tetragonal defects etc., and a built-in analyzer of their structural properties in terms of aromatic π-sextets. This shall be useful in designs of novel polyradicaloids, including those possessing topological frustration Figs. 1 and 2, with peculiar magnetism suitable for spintronics and quantum computing applications.

Fig. 1: The Clar's structure analysis of a laterally extended Clar's goblet in the released GUI, see Nat. Synth (2026).

Fig. 2: The Clar's structure analysis of a triangulene dimer - results saved in .png via 'Save' button, see Angew. Chem. Int. Ed. 59, 12041 (2020).