Monodisperse glassy liquid crystalline conjugated oligomer films are promising for application in optics, photonics and electronics. This research has furnished fundamental understanding of the origin of chiroptical effects in glassy-cholesteric oligofluorene films and new insight into the photoalignment of glassy-nematic oligofluorene films. Specifically, cholesteric films, which emerged upon thermal annealing of spin-cast films of chiral oligofluorenes, showed an order-of-magnitude increase in circular dichroism and a handedness reversal in circularly polarized fluorescence compared to the amorphous pristine films. The oligomer chain length played an important role in solid morphology. The orientation of monodisperse glassy-nematic oligofluorenes was characterized on photoalignment layers comprising a polymethacrylate backbone with coumarin pendants. A transition from a parallel to a perpendicular orientation with reference to the polarization axis of UV-irradiation was observed at a high extent of coumarin dimerization. A kinetic model was used to interpret the photodimerization of coumarin and to evaluate the relative importance of the factors affecting the crossover behavior.

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