Study On Design, Synthesis And Characterization Of Novel Organic Functional Fluorescent Molecules

Organic electroluminescent materials have attracted much attention in the research of optoelectronic information materials for the various advantages compared with inorganic light–emitting diodes. In this dissertation, a series of 1,8-naphthalimide and carbazole-acridine derivatives for organic light-emitting diodes were designed and synthesized. Then their optoelectronic properties were investigated. Furthermore, sensors based on 1,8-naphthalimide group or acridine-1, 8-dione as the fluorephore were designed and synthesized. And their chemosensing properties were also investigated. The dissertation was divided into the following parts:Firstly, A series of novel compounds comprising triphenylamine and 1, 8-naphthalimide groups were synthesized via Suzuki cross-coupling. Their absorption, luminescence and electrochemical their characteristic in dichloromethane solution were studied. They have fluorescence emission ranging from 584 - 610 nm, and triphenylamine groups decreased the HOMO energy levels of these compounds.Secondly, we have developed a novel simple naphthalimide derivative bearing the terpyridine as receptor and investigated its chemosensing properties toward Zn²⁺ ions. The naphthalimide derivative exhibited a pronounced Zn²⁺-selective fluorescence enhancement behavior, especially, that selective enhancement was unaffected while other ions existing.Thirdly, a family of carbazole-acridine derivatives were designed and synthesized. These compounds exhibited good green fluorescence with the maximum wavelengths ranging from 435 nm to 441 nm. There were intermolecular energy transfers because of both electron-donor carbazole group and electron-acceptor acridine-1, 8-dione group in the molecules. Cyclic voltammetry illustrated that the materials had high HOMO energy levels, implying that they had well hole-transporting properties. These compounds can be applied as good dopant emitter with hole transporting in OLEDs.Finally, a new acridine-1, 8-dione derivative containing the dipicolylamine group as a receptor was prepared, which exhibited the Cu²⁺-selective ON-OFF type signalling behaviour among various metal ions. Moreover the highly selective fluorescent change was unaffected by the simultaneous presence of other metal ions. Therefore this compound could be potentially utilized as a probe for monitoring Cu²⁺ levels in physiological and environmental systems. Especially, the sensor also exhibited a Cu²⁺-induced ON-OFF-ON type of fluorescent signalling pattern, which could be utilized for the construction of more elaborate supramolecular switching system.