| Molecular self-assembly processes widely exist in nature, which make human and natural prosperity. Molecular self-assembly also provides a good means for many people to simulate and study the wonderful phenomenon of nature. Therefore, more and more attention were received to the design of environmental responsive supramolecular multifunctional materials. Naphthalimide fluorescent dyes with long alkyl chains gelator were synthesized in this thesis. After adding other organic molecules which can interact with gelator, the controllable functionality was achieved in these self-assembly systems. On this basis, we try to prepare the light-emitting nanoparticles with light switch function. Nanoparticles in cell imaging process were real-time tracked. This thesis includes the following three parts:1. Fluorescence and morphology modulation in a photochromic diarylethene self-assembly systemTriazine amine trimer plays an important role in supramolecular self-assembly through form of multi hydrogen bondings. On the basic of this special characteristics of triazine amine, we synthetized and focused on the novel naphthalimide gelator and diarylethene derivatives with triazine amine as the terminal group forming self-assembly system in ethyl acetate. The diarylethene derivative structure was changed by the irradiation of UV/Vis light. The reversible changes of the conjugate of the diarylethene structure gave rise to the influence on the entire system of self-assembled molecular interactions. This structure change further led to the reversible change of morphology and fluorescence in the self-assembly. The surface wettability change was also produced by the change of the morphology in the self-assembly. This study provide a good example of multi-functional smart materials.2. Iridium(â…¢) complexe induced white organic/inorganic hybrid gelIridium(â…¢) complexes had a broad absorption band which overlaped the emission spectra of the conpound under the 405 nm excitation. This result was met the demand of energy transfer. The energy transfer phenomenon in liquid and gelation states were carried out in detail. The energy transfer efficiency in both liquid state and gelation state was increased with the amount of acceptor increasing. At the same time, the addition of Iridium(â…¢) complexes did not affect self-assembly of the compound. On the basic of the energy transfer between Iridium (â…¢) complex and compound, white light emission gel was successfully achieve.3. Dual-mode light-emitting nanoparticles and cell imaging applications explorationWater-soluble UCNPs nanoparticles were synthesized by reverse microemulsion method. Photochromic diaryl derivatives BTE was grafted on the amino group of UCNPs terminal through the formation the chemical bond. Preliminary extracellular experiments showed the nanoparticle had the light switch function. The fluorescence emission of UCNPs was switched by varying UV and Vis light. While the BTE was in optical steady-state, the UCNPs could effectively be excited by 980 nm continuous laser and re-lighted. This opened a new window for real time tracking nano-particles in the cells or in vivo imaging. Unfortunately, the organic compounds were dissociated from the nanoparticle in the cell imaging process. Although the experiment did not achieve the intended purpose, but provide some theoretical and practical experience for us to further design of functional nano-particles.
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