Vibrational properties of two fullerene-thiophene-based dyads

New dyads of the fullerene C-60 with ethylenedioxythiophenyl (EDOT) and hexylthiophenyl (HXT) groups were investigated using the infrared absorption and Raman scattering spectroscopies. The experimental methods were supported by the quantum chemical calculations of the equilibrium geometry and normal mode vibrations of the dyads. Taking into account the results of normal modes calculations, the description of the observed absorption bands and Raman lines are proposed. It was shown, that change in molecular structure of the dye leads to specific changes in the IR spectra. Spectrally observed effects authorized us to state that infrared absorption spectroscopy can be successfully used for characterization of such complex molecular systems as thiophene-fullerene dyads. (C) 2009 Elsevier B.V. All rights reserved.