The Synthesis Of Novel Discotic Molecule And Research On Its Related Compounds' Liquid Crystal Properties

Discotic liquid crystal moleculeshave a strong self-assembleperformance,stable structure orderly arrangement,excellent photoelectric properties, as well as significant low-cost processability. All these characteristics make it an ideal organic semiconductor material. And it also has broad application prospects in organic ?eld effecttransistors(OFETs),organic light emitting diodes(OLEDs),and organic photovoltaic devices(OPVs). So that it has great significance to design and synthesis of novel discotic molecules, hoping that it could have liquid crystal properties and then be applied to optoelectronic devicesas an organic semiconductor material.Therefore,several novel discotic molecules have been designed and synthesized based on their design and synthesis theories.In addition the liquid crystalproperties of these compounds have also been studied.A series of novel perylene discoticmolecules were designed and synthesized. The author used sodium dithionite to reduce the carbonyl sitessuccessfully and the compound was then etherified to obtain the target molecule.Peripheral modifications can improve its solubility whichmake it easy to process.The series of molecules' structures were confirmed by UV-Vis, 1HNMR, 13 CNMR and MS, and the thermal properties were measured by TG, DSC and POM.The optical energy gap(Eopt) and ionization energy(IP) were obtained by experimental test,the HOMO energy level is about-5.74 eV, and the LUMO level is about-3.69 eV, which is a p-type material and can indentify that the series of molecules as a narrow band gap compound. They can be used as a potential material for solar cells.During the process, the author also designed and synthesized two novel long-chain alkyl-substituted difurocoumarins, which could enrich the type of coumarin derivatives.The paper also studied on the synthesis method of the halogenation of difurocoumarins, and its solubility was improved by the external modification.The structures of the above compounds have been characterized andtheir thermal properties were tested.The new type of liquid crystalline molecules of hexabenzocoronene had been synthesized in our group, they are HBC-(CH2)2S(CH2)2C6C8 ?HBC-(CH2)2S(CH2)2C8C10?HBC-(CH2)2S(CH2)2C10C12?HBC-Br and HBC-C8-C=C.The liquid crystal properties were studied by DSC and POM. The optical energy gap(Eopt) and ionization energy(IP) were obtained by experimental test,the HOMO level ofHBC-(CH2)2S(CH2)2CnCm was about-5.90 eV and the LUMO level was about-3.29 eV. The HOMO level of the HBC-Br compound was-6.00 eV and the LUMO level was-3.52 eV. The HOMO level of the HBC-C8-C=C compound was-5.61 eV and the LUMO level was-3.00 eV. These molecules are p-type material ? The correlation test of the novel hexabenzocoronene discotic liquid crystal molecules lays the foundation for the application of the device.