Raman frequency dispersion studies of substituted polythiophene films

Styryl substituted terthiophene species have been used to produce neutral polythiophene species which show distinct Raman frequency dispersion. The polythiophene line B band shows dispersion values of: -0.12, -0.07, -0.1 cm−1 nm−1 for the phenyl, para-methoxy phenyl and para-cyano phenyl systems respectively. This is smaller than the dispersion values reported for polythiophene presumably because the intramolecular stacking forces that oppose the normal dispersion effect are suppressed due to the substituents we have used.