Synthesis And Properties Of Some Novel Fluorescent Chemosensor

Recently, considerable attention has been focused on the design of receptors those have the ability to selectively bind and sense anions or transition ions due to their playing an important role in biology, medicine and environment science. Also because of the high sensitivity, selectivity, low detection limit for host species of fluorescent chemosensor.Functional moieties such as urea, thiourea, and amide that can form relatively strong hydrogen complexes with anionic species and rely less on pH values have been extensive exploit in the design and synthesis of anion receptors. Many fluorescent chemosensors follow the approach of the covalent attachment of signaling subunits and binding sites, the coordination site binds the anion with high selectivity and the signaling subunits is to act as a signal transducer with sensitive optical response. These sensors are significant towards anion-recognition-based real-time assay of environmental anionic contaminations, clinical diagnoses of deleterious anions and microanalysis.In this thesis, a series of anion and ion receptors bearing anthracene fluorophore were synthesized and their binding properities with a variety of anions and ions were studied. The main contents are as follows:1. The Binding Sites of Receptors and the Fluorescent Chemosensor for Anions In this chapter, receptors bearing various anion binding sites chemosensors were reviewed. Their ability to selectively bind and sense anions were detailed presented.2. Study on Synthesis and Anion Recognition of the Fluorescence Receptor Containing Amide GroupA series of novel anion receptors bearing anthracene fluorophore and sulfonamide were synthesized and identified by 'H NMR, 13C NMR, MALDI-TOF and elemental analysis. The interaction between the receptor and various anions( AcO^-, H₂PO₄^-, HSO₄^-, NO₃^-, F^-, Cl-, Br- and I-) was studied by fluorescence spectrum. The results demonstrate that receptor 2-3²-5 had an excellent selective recognition for AcO^-, H₂PO₄^-, F^-, Receptor 2-6 binds anions F^-, AcO^-, H₂PO₄^-, HSO₄^-. The obtained fluorescence data indicate that 1:1 stoichiometry complex is formed between receptor 2-3²-6 with F^-, AcO^-, H₂PO₄^-, HSO₄^-.3. The Synthesis of a Fluorescent Chemosensor Containing two Thiourea Groups and Its Recognition Behavior for F^-, AcO^-.A novel anion receptor bearing anthracene fluorophore and thiourea groups was synthesized and identified by 'H NMR, 13C NMR, MALDI-TOF and elemental analysis. The interaction between the receptor and various anions(AcO^-, H₂PO₄^-, HSO₄^-, NO₃^-, F^-, Cl^-, Br- and I- ) was studied by fluorescence spectrum, The obtained fluorescence data indicate that 1:1 stoichiometry complex is formed between receptor with F^- and AcO^- through a hydrogen-bonding interaction, Receptor 3-2 has stronger affinity with F^-.4. Study on Synthesis and Transition Metal Cation Recognition of the Fluorescence Receptor Containing Amide Group A novel transition metal cation receptor bearing anthracene flurophore and amide and sulfonamide binding sites was synthesized and identified by 'H NMR, 13C NMR, MALDI-TOF and elemental analysis. The interaction between receptor 4-3 and various cations (Fe³⁺, Ca²⁺, Mg²⁺, Cu²⁺, Co²⁺, Ni²⁺, Ba²⁺, Mn²⁺, Zn²⁺, K⁺, Na⁺) was studied by fluorescence spectrum. The obtained fluorescence data indicate that 1:1 stoichiometry complex is formed between receptor 4-3 with Fe3+. Receptor 4-3 has no affinity with other metal cations.