Jahn-Teller effect and possible superconductivity in [18]annulene

We discuss the Jahn-Teller effect and possible superconductivity in negatively charged [18]annulene, (CH)18, which has a highly symmetric D6h geometry in the neutral state. Electron-phonon coupling constants in model one-dimensional crystals of (CH)18− and (CH)183− are calculated and analyzed using the density functional B3LYP method. The lowest two frequency modes (116 cm−1 and 405 cm−1) causing distortions of the C-C framework of [18]annulene and the highest frequency mode (3201 cm−1) of C-H stretching appear to give significant electron-phonon coupling constants. Possible preconditions under which idealized one-dimensional crystals of (CH)18− and (CH)183− can exhibit superconductivity at finite temperature are considered.