Triangulenes and theirs ions: reaching the limits of Clar’s rule
The triangulenes and their closed-shell ions are a family of polycyclic aromatic hydrocarbons (PAH) that have possible applications in fields as different as spintronics or catalysis. However, the electron delocalization in such systems is not well understood because there are several differences to more classical PAHs. We found that the triangulene cations are always more delocalized than the radicals or the anions, independently of the e- count. Contrary to any other PAHs, the e- of triangulenes and their ions are delocalized throughout the whole molecule and are even more delocalized than acenes. Moreover, neither the radicals nor the ions follow Clar's rule. We show that these triangular molecules are a unique type of PAHs.