Design, Synthesis And Property Study Of Novel Nitrogen-Containing Fluorescent Heterocompounds

Optical functional materials could sense, detect and transfer the signals of incident radiations (e.g. light, heat, electricity and magnetic fields) through their optical properties changes. Among them, organic optical materials, and more particularly, the nitrogen-containing fluorescent heterocompounds, which are superior to other kinds of compounds and are hence suitable for use in many fields, for example, photolumicescence and electroluminescence, have attracted considerable attentions..In present work,a series of new nitrogen-containing fluorescent heterocompounds have been designed and synthesized. The optical, thermology and electrochemistry properties have been studied to explore the applications of these compouds in fluorescent sensing (Cd²⁺ sensors and Hg²⁺ sensors) and Organic Light Emitting Diode (electron-transport materials and luminesent materials).Thirteen of new fluorophores derivatived from 1,8-naphthyridine with tuneable optical properties have been developed. D1 was the first 1,8-naphthyridine-based sensor that could exhibit a high selectivity and sensitivity for Cd²⁺ with fluorescent enhancement and red-shift by forming 1:2 complex with Cd²⁺ ions utilizing synergistic action.Novel Hg²⁺ fluorescent sensor based on 1,8-naphthyridine (HA-1) has been designed and synthesized. HA-1 are based on the combination of FRET of two fluorephores (1,8-naphthyridine and 1,8-naphthalimide) and PET mechanisms. When HA-1 was excited by the excited wavelength of the donor in FRET (1,8-naphthyridine), two fluorescent peaks of the donor and accepter (for FRET) and ratiometric fluorescent signals were observed.Six novel Fluorine-Boron cored fluorescent complexes with N^{^} N ligand were designed and efficiently synthesized. According to the study of intermolecular interactions and crystal packing, it suggested that the accepting ablity of F atom has been improv in these B-F complexes, In BN1 and BN2, the features, such as intensive fluorescence in solid/solution, better electron-accepting ability, enhanced their potential charge-transport properties of interest for practical applications in OLED. The photo-dimerization [2+2] of compound BN5 has been studied to explore the mechanism and the contribution of the B-F core in these reactions.Seven novel fluorescent Fluorine-Boron complexes with N^{^}O (BO1-BO7) have been designed and synthesized. Crystals were obtained by direct diffusion of aether into a solution of them in dichloromethane, respectively. H-bonds and crystal packing of these crystals were discussed. The fluorescent intensity of BO1-BO5 were low, but the good thermology stability and electron-accepting features make them more promising in practical applications as charge-transport materials. BO1 has been successfully used in solar cell as charge-transport materials, showing nice electron-accepting abilities and stable conversion efficiency. BO6 and BO7, combining the structural features of BODIPY and Donor-Acceptor (D-A) architecture, have been efficiently synthesized and well characterized. Significant features, such as strong fluorescence in solution and solid state, unusual large Stokes shifts, and lower LUMO and higher HOMO levels, are observed in these two structural isomers. These properties qualify them as multifunctional flurophores that can be employed in light-emitting or sensing applications.