Functionalized Triphenylene Discotic Molecules: Synthesis and Mesomorphic Characterizations

Abstract

We report the synthesis and characterization of two sets of triphenylene derived discotic molecules with phenol, aldehyde and acid functional groups. In the first set, triphenylene moiety was tethered with benzene derivatives via an ester linkage, while in the second set via an ether linkage with increased aromatic conjugation. All the molecules have triphenylene disc at one end and with benzene, biphenyl and terphenyl cores at the other end connected via flexible methylene spacers. The chemical structures of the novel compounds were confirmed by IR, NMR spectroscopy and CHN analysis methods. Thermal and liquid crystal texture properties were determined using differential scanning calorimetry, polarized optical microscope and X-ray diffraction studies. Amongst all the novel compounds, only the terphenyl derivative displayed mesomorphism. However, their charge transfer complexes with trinitrofluorenone (TNF) an electron acceptor exhibited columnar mesophases.