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Study On The Synthesis And Fluorescence Properties Of Coumarin Derviatives

Posted on:2015-02-07Degree:MasterType:Thesis
Country:ChinaCandidate:Y G ZhangFull Text:PDF
GTID:2251330431950965Subject:Inorganic Chemistry
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In this thesis, we have designed and synthesized some different courmain derivatives. The fluorescence selectivity of the ligands for metal ions has been carefully studied, respectively. The four main parts includes:In the first section, we briefly describe the mechanism of fluorescence and the composition of fluorescent sensors. We introduce the common mechanisms of fluorescent sensors and the progress of coumarn-based sensors in detail.In the second section, we designed a coumarin-based Shiff base (H2L1) as a highly sensitive fluorescent sensor for Al3+in mixed methanol-water solution. As a control study, H2L2was designed to study the function of hydroxyl in the aminophenol. From the study, we can conclude that the hydroxyl in the aminophenol play a vital role in the selective recognition of Al3+. When coordinated with Al3+, the fluorescence of H2L1was significantly increased due to the inhibition of the C=N isomerization process and photoinduced electron transfer process.In the third section, we designed a coumarin-based hydrazine (HL3), which showed strong fluorescence. This molecular was composed of a conjugated couple of electron-donating/electron-withdrawing groups, which showed intense fluorescence due to the internal molecular charge transfer. Cu2+can quench the fluorescence of the ligand completely, while other metal ions can’t.In the fourth section, we synthesized coumarin-based benzimidazole derivate. This ligand gives out strong blue fluorescence under the excitation of ultraviolet light. When binding with Cu2+, its fluorescence was completely quenched in mixed methanol-water (Tris-HCl, pH=7.2,20mM). This probe shows good selective quench effect for Cu2+against other metal ions. Besides, this ligand also presents good two-photon fluorescence, which is friendly to the environment and animals.
Keywords/Search Tags:Coumarin, Al3+, Cu2+, Two-photon
PDF Full Text Request
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