Based On The Synthesis And Luminescence Properties Of Small Molecule Compounds 1,8 - Naphthyridine System

Directed by professor Fu Wen-fu Today a transition from electronic era to photo electronic era has occurred, the study in photo electronic material attracted more attention of all kinds of groups in the society. In the present, the development of small molecular complex used as blue luminescent materials has been improved greatly. In order to satisfy full color display, the lack of blue material must be resolved. In this paper, we are engaged in the design and synthesis of some ligands which not only can emit blue luminescent but also can coordinate with metal. Their structure were determined by X-ray diffraction,1HNMR,FAB-MS,IR etc. The investigation of photochemical and photophysical properties of the compounds had been performed by the spectra of UV-Vis, the emission and the excitation spectra. In the research, we accidentally find two of them are sensitive not only to light but also to pH. According their photo properties in different surrounding, we also speculated the mechanism of luminescence.1. We designed and synthesized a new ligand 2-amine-7-chloro-1, 8-naphthyridine.Its structure had been determined by 1HNMR,FAB-MS and X-ray diffraction. The result shows that the molecules can form three-dimensional reticulate supermolecular structure not only by hydrogen bond but also by π-π stack in naphthyridine molecules. After coordinating to metal to form the complex, it also can form supermolecular through hydrogen bond and π-π stack. The research in fluorescent properties shows that this kind of compound displaies intensive bluefluorescent and can act as blue luminescent materials. 2. According the request of photo "on/off", we designed and synthesized two kinds of ligands which contain double bond: 2-styryl-1, 8-naphthyridine and p-di(2-1, 8-naphthyridiyl-vinyl)benzene. Their structures were determined by IR,1HNMR,FAB-MS,ESI-MS,GC-MS etc. Their fluorescent spectrums show that both of them have good emit in blue region. They also have sensitivity to pH. In acid surrounding the emission spectra red-shifted, in base surrounding the wavelength of emission hardly is changed. Combining the emission and excitation spectra, The emissions are assigned to come from ICT (intramolecular charges transition) transition.3. When photophysical properties of 2-styryl-1, 8-naphthyridine are investigated, we accidentally find this compound have sensitivity not only to pH but also to light. The emission maximum in 412nm and 486nm probably come from cis- and tran- isomers. In polar solvent, the compound can form hydrogen bond with solvent, so in the beginning the compound are cis- and it's emission is in short wave region. After the molecular irradiated, the cis- turned to trans-, which results in the red-shift of emission wavelength.