Synthesis Of Fluorescent Probes Based On Metal Ruthenium(?)/Iridi Um(?)Complexes And Their Performance In The Detection Of Physi Ologically Active Small Molecules HOCl/H₂S

Due to its unique triplet excited state,transition metal complexes exhibit excellent photophysical and chemical properties:larger Stokes shift,which can effectively distinguish excitation and emission wavelengths;long fluorescence lifetime,easier to combine with time-gated detection technology to effectively shield the background Self-interference of fluorescence;near-infrared luminescence,which can penetrate deeper into tissue cells and effectively avoid background noise.Due to their excellent fluorescence properties,transition metal complexes have received extensive attention in molecular/ion probes,bioimaging and disease detection.In this article,the complexes centered on ruthenium(?)and iridium(?)are selected as fluorescent emitting groups,and different recognition groups are introduced by modifying the peripheral ligands to synthesize three new metal complex fluorescent probes,and It has been successfully applied to the detection of analytes in actual water samples.1.HOCl has strong oxidizing properties and can oxidize S atoms into sulfoxides.At the same time,HOCl is easy to decompose,requiring the probe to have the ability to detect instantaneously.We designed and synthesized a phenothiazine derivative,which contains N^N sites that can coordinate with metal ruthenium(?),and can react with HOCl instantaneously to achieve the purpose of instantaneous detection.After the S atom is oxidized to sulfoxide,the metal-ligand charge transfer(MLCT)is transferred,and the fluorescence intensity changes.2.The metal Ir(?)complex fluorescent probe Ir-NBD containing NBD-Cl was synthesized.Due to the strong PET interaction between NBD-Cl and the probe Ir-NBD,the probe showed weak fluorescence.When S^2—/HSO₃^-and the probe occur,the NBD group connected with piperazine falls off,the PET effect disappears,and the metal Ir(?)complex containing only piperazine is generated,thereby increasing the fluorescence and achieving the recognition effect.3.The 2,2'-bipyridine derivative ligand containing morpholine positioning group was used to synthesize a near-infrared ruthenium complex fluorescent probe Ru-OH for rapid identification of Cu²⁺in water.The ligand contains a Coordination site with Cu²⁺.The paramagnetism of Cu²⁺can cause fluorescence quenching when combined with the probe,which completes the recognition of Cu²⁺.