Photoluminescent Color and Polarized Light Emission Tuning of Fluorene Derivatives Using a Photoreactive H-Bonded Liquid Crystalline Polymer

Three fluorene (FL) derivatives with pyridine end groups were synthesized to control the photoluminescence (PL) wavelength and polarized light emission using a photoreactive H-bonded polymer containing cinnamic acid side groups (P6CAM). The FL derivatives, which possessed pyridine end groups, formed H-bonds with cinnamic acid, and changed the PL behavior of the derivatives. The controllability lambda(max) of the PL depended on the position of the N-atom at the pyridine end group and the degree of the photoreaction of the P6CAM. For F1, lambda(max) of the PL was tuned from 470 to 518 nm. Employing P6CAM as the photoalignment layer to reorient the cinnamic acid side groups realized polarized PL up to PL parallel to/PL perpendicular to = 3.9. Furthermore, photopatterning of the PL color and the direction of the polarized light emission using patterned P6CAM films were demonstrated.