Synthesis And Study Of Hexa-peri-benzocoronene With Containing-Hetero Atoms And Swallow-tail Side Chain For Orientation

Although discotic liquid crystal molecules have not widely been applied in display technology until now, their conjugated system, self-assemble into a one-dimensional morphology, the ability of the self-healing of structural defects, high solubility in organic solvents and low temperature processing make them become potential organic semiconductor materials.Hexabenzocoronene have more strong π-π interaction and higher carrier mobility than other discotic liquid crystals therotically due to its larger conjugated system and more effective π-π orbital overlap between two adjacent molecules according to Marcus’ s theory.At the same time, different electronic devices require charge transporting materials to form desirable specific one-dimensional alignment between electrodes. Thus, it is important to study relationship between molecule’s structure and its alignment direction relative to substrate in order to control the alignment of hexabenzocoronene derivatives on the substrate. Therefore, the hexabenzocoronene molecules, which consist of swollen-tail side chains with a sulfur atom at the third carbon position in the periphery of the core and the hexabenzocoronene in the center, are designed and synthesized. We hope that the affinity between the substrate and sulfur will help the arrangement of molecules to face on the substrate. In this paper, the target molecules have been characterized by the ‘HNMR, 13 CNMR, mass spectrometry and UV-Vis, as well as with TG, DSC, POM for their liquid crystal properties.Because physisorption of HBCs’ nano-columns can not ensure long-term stability due to too weak interactions with the substrate and therefore is not appropriate for device applications, it is necessary to graft them chemically on the substrate. Thus, two hexabenzocoronene discotic liquid crystal molecules around core with five oxygen-containing swollen-tail and one long chain with vinyl or Br as tail group are designed and synthesized. The molecule with vinyl is expected to bond towards on silicon, while one with Br to synthesize one compound with thiol as tail group to bond towards on golden surface or synthesize more useful compounds as a synthon. The two molecules are also charactered by the 1HNMR, 13 CNMR, MS and UV-Vis and Their liquid crystal properties are also studied.