Synthesis And Study Of Iridium(Ⅲ) Complex-based Fluorescent Probes For Specific Dection Of Small Molecular

The iridium（Ⅲ）complex with d⁶ electronic configuration is octahedral structure,and the electronic structure of outer layer will form a strong spin-orbit coupling,resulting in the mixing of singlet and triplet excitons between organic ligands and metal center.The Ir（Ⅲ）complexes posses various excited states,which can improve their quantum yield and luminous efficiency.In addition,the Ir（Ⅲ）complexes exhibit other advantages,such as wide luminous wavelength coverage,good photostability,long fluorescence lifetime,high photoluminescence quantum yield,large Stokes shift,and effectively distinguish between excitation and emission wavelengths.Based above-mentioned advantages,we had synthesized three probes based on iridium（Ⅲ）complexes to detect small moleculars.1.The iridium（Ш）complex fluorescence Ir-CN was synthesized with-C=N-NH-structure as recognition unit.Under the strong oxidation of hypochlorous acid,the recognition structure was oxidized to an aldehyde group.The probe Ir-CN could detected HClO in mixed solutions of DMF/PBS（v/v=3/7）.The Ir-CN displayed almost none fluorescence emission at 615 nm with excition at 420 nm.After adding HClO to the solutions,the fluorescence at 615 nm was significantly increased by about23 times with high selectivity heand sensitivity（LOD=1.3728μΜ）.In addition,the Ir-CN also exhibited good water solubility,which could realize the quantitative detection of HClO in actual water samples,and had certain application prospects in the actual environment.2.A complex fluorescence probe Ir-N₃ with an azide group on N^N auxiliay ligand as recognition group for detected H₂S was synthesized.Through nucleophilic and hydrolysis reactions between H₂S and azide group of Ir-N₃ in pure PBS buffer solution,the probe Ir-N₃ was reduced to the Ir-NH₂ finally.Ir-N₃ had obvious fluorescence emission at 615 nm under excition of 380 nm with yellow fluorescence.After adding H₂S in solution,the fluorescence was rapidly quenched with highly sensitivity（LOD=0.5180μM）.And in prescence of various interfering substances,the ability of the probe to recognize H₂S was not affected.The probe had been successfully used for the quantitative detection of H₂S in actual water samples and beer samples,and had the prospect of being applied in practical environments.In addition,the probe also realized the detection of H₂S in Hela cells,which had certain potential for biological applications.3.An iridium complex fluorescent probe Ir-BMIP containing the water solubility group BMIP was synthesized for the recognition of CO₃^2-,under the excitation of 410nm,the quantitative detection of CO₃^2-was realized in a mixed solution of CH₃CN/PBS（v/v=6/4）.The probe had good sensitivity（LOD=0.0505μM）and high selectivity,and could detect CO₃^2-in the presence of various anions.