Infrared and Raman spectra of a new radical cation charged defect created on a well-barrier-well thiophene-based oligomer

We have studied the Fourier transform Infrared (FT-IR) and the Fourier tran sform Raman (FT-Raman) spectra of a well-barrier-well thiophene-based oligo mer oxidized with dry iodine vapour. These new data, when combined with the full vibrational assignment of the oligomer in the neutral state, provide a complete spectroscopic characterization of a new positive polaron-type mo del defect in an electronic segmented molecule. The FT-IR and FT-Raman spec tra were also calculated at the B3LYP16-31G** level as an aid to the vibrat ional assignment of the main bands in the whole spectral range. Copyright ( C) 2000 John Wiley & Sons, Ltd.