Oxygen- and sulfur-containing positively charged polycyclic aromatic hydrocarbons.

Benzo[5,6]naphthaceno[1,12,11,10-jklmna]xanthylium (BNAX) and benzo[5,6]naphthaceno[1,12,11,10-jklmna]thioxanthylium (BNATX) salts were synthesized. Comparison of the UV-vis absorption and emission spectra of them and dibenzo[jk,mn]naphtho[2,1,8-fgh]thebenidinium (DBNT) salts suggests that the incorporation of different heteroatoms in the same PAH core changes their optoelectronic properties profoundly. Ordered columnar liquid crystalline phases were observed for di- and tridodecyl-substituted BNAX salts. X-ray scattering and molecular modeling indicate that three BNAX molecules self-assemble into a disklike structure, which further organizes into hexagonal columnar phases.