Structural Descriptors of Benzenoid Hydrocarbons: A Mismatch between the Estimates and Parity Effects in Helicenes

Benzenoid hydrocarbons have regular structures, attracting the opportunity to test structural descriptors of their series. In present study, we compared information entropy, Wiener indices, topological efficiencies, roundness, and symmetries oligoacenes, phenacenes, helicenes. We found discussed mismatches between symmetry benzenoids. Among studied series, helicenes demonstrate parity effect when entropy roundness form saw-like functions depending on number member, odd or even. According our quantum chemical calculations, this has no consequences for such molecular properties as polarizability frontier orbital energies. Further, demonstrated that changes in upon reactions benzenoids could be used numerical description processes. Interestingly, view reaction profile is similar energy profiles reactions. Herewith, intermediate compounds higher values with initial final compounds, which reminisce activation barrier.