Theoretical calculations, dynamic NMR experiments and absorption and photoluminescence data in solution are reported for a series of quinquethiophene S, S- dioxides substituted with alkyl groups of variable size and steric hindrance. Ab initio B3LYP/6-31G∗ and force field MM3 theoretical calculations show that the energy barriers for rotation around the inter-ring C–C bonds amount to a few kcal/mol even in the presence of ...
[Fuerstner, Alois; Martin, Ruben; Krause, Helga; Seidel, Guenter; Goddard, Richard; Lehmann, Christian W. Journal of the American Chemical Society, 2008 , vol. 130, # 27 p. 8773 - 8787]
