On Diphenalenes Comprising Seven Hexagonal Rings.

ABSTRACT: Benzenoid hydrocarbons with two phenalene moieties, diphenalenes, comprising seven benzene rings, form three groups, with the seventh benzene ring fused to (i) zethrene, (ii) uthrene, or (iii) it links phenalene subunits. The DFT/cc-pVTZ calculations indicate that four molecules in the former group are more stable in the singlet state, four in the next in the triplet, whereas in the latter group, three are more stable as singlets and two as triplets. The singlet-triplet gap usually exceeds | ± 10| kcal/mol, but for two molecules of the (iii) group, it is close to 5 kcal/mol. We show also that the diphenalenes' Gibbs free energy differences can be presented as a multivariate function of the number of border Bay, Cove, and Fjord motifs. Diphenalenes, including [4]-helicene moiety, are inhere

SUBMITTER: Misztal O 

PROVIDER: S-EPMC12713576 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature