Construction And Research Of Fluorescent Probes And Supramolecular Fluorescent Assemblies

In recent 30 years, supramolecular chemistry has witnessed a great progress in the area of host-guest recognition, catalysis and the construction of smart stimuli-responsive materials, etc. In this dissertation, the construction and research of the fluorescent supramolecular assemblies would be discussed in three parts as follows:fluorescent probe, fluorescent organogels and coordination-driven self-assembly.(1) A series of naphthalimide-based fluorescent probes have been designed and synthesized, among which 2.5 exhibited highly selective fluorescence turn-on for Hg2+ and turn-off for Cu2+ in aqueous solution,2.8 exhibited an obvious fluorescence turn-on response toward Pb2+ in aqueous solution and in living cells,2.12 exhibited highly selective detection of Hg2+ in aqueous solution and living cells,2.17 responded to NO quickly and showed a 25-fold fluorescence enhancement within 10 seconds.All the fluorescent probes have been well characterized by 1H NMR, 13C NMR, ESI-MS, single crystal X-ray diffraction and other methods; The selectivity of probes was researched by selectivity and competition experiments through UV-Vis and fluorescence spectrum; The recognition principle and binding modes of the probes (2.5,2.8,2.12) and their analytes (Cu2+/Hg2+, Pb2+, Hg2+ respectively) were researched by model compounds analysis, 1H NMR titration, UV/fluorescence titration and Job’s plot experiment; The detection limit and binding constants were calculated at the same time; The reaction process of 2.17 and nitric oxide was researched by control experiment; The living cell imaging experiments demonstrated the promising application of 2.8 and 2.12 for detecting Pb2+and Hg2+ in biological systems.(2) A new family of pyrene-containing compounds 3.8,3.16,3.17 derived from aminoquinoline-containing fluorescent probe AQZ were successfully synthesized and well characterized. The investigation of the absorption and emission spectra of these compounds revealed that the photophysical properties were significantly affected by the substitution of pyrene. Moreover, these compounds exhibited selective fluorescence behaviour towards Zn2+ in aqueous solution. The gelation properties of these compounds were investigated and 1,8-bis-substituted compound 3.17 displayed stable gel-formation properties in acetone, dioxane, tetrahydrofuran, ethyl acetate, chloroform, and dichloromethane. The morphologies of the xerogels were investigated by scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM). The concentration- and temperature-dependent emission properties, and concentration- and temperature variable 1H NMR spectroscopy of compound 3.17 were investigated, which suggested that both π-π stacking interaction and hydrogen bond were the driving forces for the process of self-aggregation and the gel formation. More importantly, it was found that compound 3.17 could form a stimuli-responsive gel that had a sensitive gel-to-sol transition response to heating or adding Zn2+.(3) FRET fluorophore pair (coumarin and rhodamin) decorated Pt-N coordination-driven self-assembly macrocycles FM-1, FM-2, FM-3 have been constructed and well characterized by 1H NMR,13C NMR,31P NMR, ESI-MS, etc. The dynamic properties of coordination-driven self-assembly macrocycles have been fully researched by the real time monitoring of the FRET signal of the self-assembly process of discrete macrocycles (FM-1, FM-2, FM-3) and the dynamic ligand exchange experiment of control macrocycles (FM-4, FM-5). The disassembly and reassembly process can also be achieved by adding halogen ions and silver ion, and this dynamic process has been real-time monitored by fluorescence,1H NMR and 31P NMR experiment.