New Discoid And Rod-like Molecules Synthesis And Liquid Crystal Properties

Organic light-emitting materials possess many advance properties. Such as, easier processability, lower cost, lighter weight and manifold color-emitting et al. Thus, they generate much interest and have been widely studied. In recent years, the organic light-emitting materials forming byπ?πstacking show applications in the field of organic electro-optical devices such as OLED and OFLET.Discotic molecules areπ-conjugated compounds and have the ability to form supramolecular liquid crystals by molecular self-assembling. Since the first example of discotic liquid crystals was reported, various discotic mesogens have been synthesized. Benzene was the first aromatic core used for the construction of discotic mesogens. Two-dimensional aromatic cores, triphenylene (TP) and hexabenzocoronene (HBC) with more extended conjugation, were later employed as cores in succession. Besides these large disc-like aromatic cores, some star-like cores were used to build discotic mesogens. In this thesis, two kinds discotic mesogens were designed and synthesized. One is 2,4,6-Triphenylpyridine derivatives. The mesophase behaviors of this kinds of compounds were investigated by POM (Polarized Optical Micrograph), nematic and columnar mesophases are found in these compounds. The second kind of discotic molecules are 4-(dodecane Benzoyl-yl) porphyrin and its metal complexes. The optic-electric properties of such compounds were studed by means of UV, PL.Oligothiophene and polythiophene are another important class ofπ-conjugated compounds, it is a significant of conducted polymers, with good electrochemical activity, environmental stability and processability properties. Based on our groups study, and taken Kumada and Suzuki coupling reactions as key steps, we further synthesized six non-conventional rodlike bithiophene-based bolaramphiphilic compounds and one tetra-thiophene-based non-conventional rodlike bolaramphiphilic compounds. We also used the POM, DSC(Differential Scanning Calorimetry) and X-ray to study the mesomorphic properties of all these compounds, they all exhibited complex supramolecular liquid crystalline columnar mesophases.The optic-electric properties of some of the above compounds were studed by means of UV, PL and CV spectra.