Charge Transport in Novel Phenazine Fused Triphenylene Supramolecular Systems

摘要

Novel phenazine-fused triphenylene discotic liquid crystals (DLCs) tethered with alkanethiols and alkoxy chains are synthesized. The condensation of 4,5-dibromobenzene-1,2-diamine with triphenylene-1,2-diquinone discotic core, followed by the reaction with alkanethiols gives heterocyclic phenazine-fused triphenylene based DLCs. The intermediate dibromo-substituted phenazine and final alkanethiol substituted phenazine-fused triphenylene derivatives exhibit a wide range of stable enantiotropic hexagonal columnar phase, which was characterised by polarized optical microscopy (POM), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) studies. We have also investigated the photophysical properties of all phenazine compounds using dilute solution of anhydrous chloroform. The charge carrier mobility was measured for one representative compound by time of flight method which revealed that phenazine-fused triphenylene discotic mesogen exhibits p-type (hole) mobility of the order of 10~(-4) cm~2 V~(-1) s~(-1). The novel mesogens reported here present a wide temperature stability with good charge mobility and optical properties. These mesogens have shown potential applications for solar cells, sensors, organic light emitting diodes and other electro-optical device applications.