Room-Temperature Columnar Liquid Crystals from Twisted and Macrocyclic 9,9′-Bifluorenylidene Mesogen with Ambipolar Carrier Transport Properties

Abstract

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.