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.