Infrared and raman spectra of two well-barrier-well 1,2-Di(α,α′-oligothienyl)ethanes

The vibrational Fourier transform infrared and Fourier transform Raman spectra of two neutral thiopbene-based oligomers in solution and in the solid state were studied. The compounds have a well-barrier-well structure, where the well parts are two biothiophene or terthiophene end moieties and the barrier part is a dimethylene fragment with a larger energy gap. Characteristic features are correlated with vibrational data on one-dimensional unsubstituted α-oligothiophenes and α,α′-dimethyl end-capped oligothiophenes. Vibrational assignments are also proposed for relevant bands in the whole spectral range. © 1997 John Wiley & Sons, Ltd.