Study On Synthesis Of Conjugated Compounds Which Containing Carbazole, Pyridine Rings And Their Optical Properties

Organic electroluminescence, which called organic light emitting diode (OLED) is one of the research forefronts in the field of flat display recently. Compared with the traditional display, OLED posses excellent features such as low driving voltage, high luminescence brightness, high luminescence efficiency, fast response,wide visual view, processed into buckling display panel and so on, which be considered as a new technology to instead of LCD and plasma display in the near future. As the foundation of organic electroluminescence devices, OEL materials are one of the key factors influencing the device performance. At present, scientists concentrated on the study of luminescent materials, Arylamine materials (including diphenylamine, triphenylamine, and carbazole materials) is one kind of important electroluminesent materials.Based on the full and carefull investigation of the literature, we carried out the work including the following aspects:1. Synthesis of intermediates and target compounds(1) Intermediates and target compound 9-p-tolyl-9H-carbazole, 3,6-diiodo-9-p-tolyl-9H-carbazole,3,6-dicarbazol-9-p-tolyl-9H-carbazole was syntheseized via the reaction of Ullmann and iodination on carbazole. The optimum condition was determined.The structures of the compounds were confirme by IR and 1HNMR.(2) Eight new bicarbazole rings'conjugated compounds were synthesized by following steps. First, two compounds containing bicarbazole rings were synthesized by carbazole and 2,6-dibromine-pyri-dine, then iodine group was introduced in the 3,6 positions of dicarbazole rings, finally, arylamine groups such as diphenylamine, carbazole were introduced to dicarbazole rings. The structures of these compounds were characterized by IR,,1H NMR,13C NMR(3) Four new pyridine rings'conjugated compounds were synthe-sized by 2,6-dibromine-pyridine and diphenylamine,1-naphyl-phenyl amine benzimidazole and benzotriazole separately2. Investigation on the optical properties of target compoundsThe optical properties of the conjugated compounds contain carbazole and pyridine rings were separately determined by the UV-vis absorption and fluorescence emission spectra. The optical properties of 2,6-di(9H-carbazol-9-yl)pyridine,9-(6-(9H-carbazol-9-yl)pyridin-2-yl)-9H-3, 9'-bicarbazole,2,6-di(9H-3,9'-bicarbazol-9-yl)pyridine,2,6-bis(3,6-diiodo-9H-carbazol-9-yl)pyridine,2,6-bis(6-(9H-carbazol-9-yl)-9H-3,9'-bicarbazol-9-yl) pyridine,2,6-di(1H-benzo[d]imidazol-1-yl)pyridine were separately determined by the UV-vis absorption and fluorescence emission spectra in different solvents. The absorption and fluorescence spectra of these compounds exhibited red-shifted in stengthen polarity solvent and with donating electron group. the fluorescence emission intensity of the compounds can be quenched by diphenylketone and triethylamine, the quenching process followed the Stern-Volmer equation well.