Design,Synthesis And Metal Ions Recognition Properties Of Triazine Derivative As Fluorescent Probe

Metal ions play an important role in many physiological processes such as gene transcription,regulation of metal enzymes and maintenance of macromolecular structures and functions such as protein and nucleic acid.However,with development of modern industry,a large number of metal ions are released into the environment,caused a serious threat to life systems.Excess of silver ions?Ag⁺?in the body can induce accumulation of insoluble substances,causing serious damage to eyes and skin.In addition,Ag⁺can also cause health problems such as organ failure and mitochondrial dysfunction.Copper ions(Cu²⁺),as an essential element of the human body,its abnormity in body will also cause metabolic disorders,aging and various neurodegenerative diseases and so on.In recent years,fluorescent probe has become an effective tool for detecting metal ions in the environment and living organisms due to its advantages of good selectivity,high sensitivity,simple operation and low cost.2,4,6-Trichloro-1,3,5-triazine is an electron-deficient aromatic molecule,it is cheap,easy to be modified and has symmetrical structure,strong electron affinity.N,N,N-tridentate ligands with"push-pull"?-electron effects based on 2,4,6-trichloro-1,3,5-triazine,have coordination abilities to the various metal ions and the special photophysical properties such as high fluorescence quantum yield and two-photon absorption.Ag⁺and Cu²⁺,which are related to living systems,were selected as the research objects.A series of fluorescence probes were designed and synthesized based on 2,4,6-trichloro-1,3,5-triazine.?1?We combined 2,4,6-trichloro-1,3,5-triazine with 5-methyl-1H-pyrazole-3-carboxylate or?1H-pyrazole-1,3-diyl?diacetate,and synthesized a series of structure similar compounds NTPC,OTPC,NTPA and OTPA.And we discussed their synthetic methods and photophysical properties.Then,the selectivity of these compounds to metal ions was studied by UV-vis spectra and fluorescence spectra.We selected probes NTPC and NTPA because of their high selectivity to Ag⁺and long emission wavelength,and their detection abilities and recognition mechanism were studied and analyzed in detail.NTPC and NTPA exhibited high selectivity,short response time,low detection limit,good reversibility,pH insensitivity and low cytotoxicity,and were successfully applied to fluorescence imaging of Ag⁺in living cells.?2?The"turn-on"Cu²⁺fluorescence probe TPH and"turn-off"Cu²⁺fluorescence probe TPA were designed and synthesized based on 2,4,6-trichloro-1,3,5-triazine.We studied the recognition mechanism of TPH and TPA to Cu²⁺in detail by UV-vis spectra,fluorescence spectra and mass spectra.The results showed that the ester bond of TPH was hydrolyzed in Cu²⁺aqueous solution resulted in fluorescence enhancement,and TPA coordinated with Cu²⁺in a stoichiometric ratio of 3:2 resulted in fluorescence quenching.