Jahn-Teller distortion and possible electron pairing in molecular systems

Negative effective electron-electron interaction (U) due to Jahn-Teller distortion and its role in molecular superconductivity are discussed in degenerate molecular systems. It is demonstrated within the Hückel molecular orbital theory that the U value could become negative in the ± 1 and ± 3 charged states of [N]annulenes, (CH)N ring systems, with D6h geometry, where N = 6(2m + 1) (m = 0, 1, 2, 3, ⋯). Possible intermolecular electron pairing between two electrons with opposite discrete molecular wave vectors is proposed.