The Study Of Synthesis And Optical Sensing Performances Based On Functional Metal Complexes

By using various ligands and their corresponding complexes, detailed analyses have been devoted to the following issues. （1） The Hg（Ⅱ）-sensing properties of functionalized mesoporous MCM-41 with a covalently linked Eu（Ⅲ） complex; （2） The oxygen-sensing properties of Eu（Ⅲ） complexes incorporated in different matrices and the luminescence quenching mechanism of the oxygen-sensing Eu（Ⅲ） complexes; （3） The pH-sensing properties of Ruthenium（Ⅱ） polypyridine complexes; （4） The effect on photophysical properties of Cu（Ⅰ） complexes by modulating the complexes molecule structure. The above mentioned research efforts lead to the following results:（1） A novel Hg（Ⅱ） chemosensor based on a water-soluble Eu（PTA） complex covalently grafted to the ordered functionalized mesoporous MCM-41 backbone was synthesized. The detection limit for Hg（Ⅱ） in aqueous solutions is as low as 0.6μmol/L, and other metal ions possess a little influence on the determination for Hg（Ⅱ）, suggesting the possibility for real-time qualitative or quantitative detection of Hg（Ⅱ）, as well as a wide potential application in environmental monitoring.（2） A novel Eu（Ⅲ） complex of Eu（DPIQ）（TTA）₃ was synthesized and encapsulated in the mesoporous MCM-41. The composites exhibited the characteristic emission of the Eu³⁺ ion and the fluorescence intensity of 5D0-7F2 obviously decreased with increasing oxygen concentrations. The oxygen-sensing properties of the composites with different loading levels of Eu（DPIQ）（TTA）₃ complex were investigated. A sensitivity of 3.04, a short response time of 7 s, and good linearity were obtained for the composites with a loading level of 20 mg/g. These results are the best reported values for optical oxygen-sensing materials based on Eu（Ⅲ） complexes so far.（3） A new Eu（Ⅲ） complex of Eu（N-DPIQ）（TTA）₃ was synthesized and incorporated in poly（vinylpyrrolidone）（PVP） by electrospinning. By comparing the oxygen-sensing properties of the composite nanofibers with different loading levels of Eu（Ⅲ） complex, the highest sensitivity of 2.34, a short response time of 10 s were achieved for the composite nanofibers with a loading level of 4 wt%.（4） Two pH-sensing Ru（Ⅱ） complexes were synthesized. Both of them exhibited characteristic MLCT3 emission derived from a triplet MLCT3 （Ru（dπ）â†'dÏ€*（ligand）） transition. The investigation indicated the change of UV-vis absorption and emission spectra of Ru（Ⅱ） complexes upon different pH in aqueous solution were attributed to the different protonation /deprotonation processes of the protons on imino group of the imidazole ring and hydroxyl of benzene ring.（5） Two new Cu（Ⅰ） complexes with phenanthroline derivatives as the ligands were synthesized. The photophysical properties of the Cu（Ⅰ） complexes were investigated by means of UV-vis absorption spectra, excitation- emission spectra and lifetime decay curves. The study of photophysical properties indicated that the Cu（Ⅰ） complexes exhibited olive emission, and the introduction of ethyl group to the ligand led to the red-shift of Cu（Ⅰ） complex emission.