Room-Temperature Columnar Liquid Crystals from Twisted and Macrocyclic 9,9'-Bifluorenylidene Mesogen with Ambipolar...

We herein report the synthesis and characterization of a series of twisted and conjugated 9,9'-bifluorenylidene (BF) derivatives and a ladder-shaped cyclic dimer (CBF) bearing eight long alkoxy chains at peripheral positions. These contorted aromatics formed hexagonal columnar liquid crystalline mesophases over a wide temperature range, including room temperature. Ambipolar carrier transport properties with electron and hole mobility values of approximately 10^-4 and 10^-5 cm² V^-1 s^-1, respectively, were achieved for the BF derivatives forming a monodomain orientation at ambient temperature.