Design, Synthesis And Application Of Fluorescence Molecular Based On ICT

With the rapid development of industry, large amounts of toxic and harmful pollutants are brought about, such as heavy metals, nitro phenol, PCBs, benzene hydrocarbon et al. The problem of environmental pollution is becoming more and more serious. Hence, fast and sensitive detection of toxic, hazardous and explosive substances both in environment and organisms is a challenging, which has important theoretical and practical significance. Traditional detection methods such as high performance liquid chromatography, inductively coupled plasma mass spectrometry, neutron detection technology and X-ray method are subject to some disadvantages due to high cost, complicated operation, lengthy response time and other shortcomings. Accordingly, there remains a need for new simple and easily-prepared fluorescence molecular probes for the rapid, sensitive, selective visual detection of toxic, hazardous and explosive substances. As a consequence, the design, synthesis of high selectivity and high sensitivity fluorescence molecular probe has a great application prospect and become the hotspots in the field of scientific researchers. Based on the mechanism of the intramolecular charge transfer (ICT), in this dissertation, three series organic fluorescent molecule:coumarin derivatives, pyridine derivatives, quinaldine derivatives were designed and synthesized over reviewing on the researches of chemical sensors, for the detection of Hg(Ⅱ) and explosives (picric acid (PA) and 2,4-dinitrophenol (DNP). The main achievements are listed as follows:1. In view of the excellent optical properties of coumarin compounds, such as high fluorescence quantum yield, large Stokes’shift and good light stability and so on, two different functional groups of coumarin derivatives (T1 and T2) we designed, synthesized and characterized. The theoretical calculation and experimental results demonstrated that the compounds with the properties of ICT. The physical properties of T1 and T2 after adding PA were also carried out, the results show that T1 and T2 can be used as excellent properties of probes for the recognition of PA or DNP. T1 can realize the detection of PA in methanol, the detection limit is 87 ppb; the detection limit of T2 to PA or DNP is 467 ppb and 600 ppb, respectively.2. On the basis of ICT, we introduced strong electron-donating group of amino and electron-drawing group of pyridine group, designed and synthesized two kinds of simple structure and easy to synthesize of D-π-A (D=donor, A=acceptor) structure fluorescence probes T3 and T4. The photo-physical properties of T3 with Hg(Ⅱ) and T4 with PA were studied. The results show that T3 can detect Hg(Ⅱ) by the naked-eye, the detection limit is 0.174 ppb; T4 can be used as excellent properties of probes for the recognition of PA, the detection limit is 400 ppb. We got red bulk crystal after self-assembly of the T4 with PA. Single crystal X-ray diffraction results revealed that a variety of hydrogen bonds and π-π interactions play an important role in the assembly of the supramolecular structure.3. Based on the mechanism of ICT, using 4-amino quinaldine salt as precursor compound occurred Knoevenagel condensation reaction with 4-dimethylaminobenza-ldehyde,4-(N,N-diphenylamine)benzaldehyde and 7-(diethylamino)coumarin-3-carb-aldehyde, respectively, obtaining three red emitting materials with D-π-A conjugated structure T5, T6 and T7. We also studied the photo-physical properties of T5, T6 and T7 with PA, the results show that the T5 and T6 has the ability of detection of PA, the detection limit of T5 and T6 to PA is 4.7 ppm and 3.6 ppm, respectively. In addition, T5 as the precursor compound by replacing different anion (TsO-, NO3-, Hg(SCN)3-, Cd(SCN)3-, SCN-, Zn(SCN)3-), and got high solid luminescent material, to adjust light band (574 nm～645 nm), thus providing theoretical and experimental basis for the research and development of novel organic luminescent materials. 属性不符...