The Design And Synthesis Of Ir(?),Pt(?)Complexes And Their Applications In Sensing And Imaging

Phosphorescent transition-metal complexes(PTMCs)have been attracting significant attention because of their excellent luminescent properties and promising optoelectronic applications.They exhibit high luminescence efficiency,the tunable excitation and emission wavelength over the whole visible(even near-infrared)range,significant stokes shifts(often >5000 cm-1)for easily distinguishing emission over excitation and eliminating self-quench,and relatively long lifetimes(hundreds of nanoseconds to tens of microseconds,much greater than those of purely organic luminophores)etc.In particular,by virtue of the long lifetime of the transition-metal complex,autofluorescence from biological samples can be eliminated by time-resolved fluorescent imaging.All these characters are very beneficial for PTMCs to be used in chemical sensing and bioimaging.In this thesis,we aimed to develop new phosphorescent transition metal complexes and study their photophysical properties and their response to target analytes.The main contents are showed as follows:1.Aggregation induced phosphorescence platinum(II)complexes: design,synthesis,photophysical properties and cell imaging applicationsBased on the previous work,three new platinum complexes with schiff base ligand were synthesized by introducing electron and electron withdrawing substituents to the schiff base ligands.Their structures were characterized by 1H NMR,and the single crystal structure of the complex ppyPtN-PhF5 was analyzed by X-ray,and their photophysical properties were studied by UV-vis absorption spectra and fluorescence emission spectra.At room temperature,these three complexes did not emit light in solution,but exhibited a strong phosphorescence emission in solid state,and the maximum quantum efficiency is 0.39.The introduction of methoxy group(electron-donating unit)had little influence on the maximum emission peak,while the introduction of pentafluorophenyl unit(electron withdrawing substituent)led to the red shift of the emission.In addition,mesoporous silica nanoparticles with core-shell structure were used as probe carriers to adsorb ppyPtN-PhM and formed nano phosphorescent biological probes Pt1@MSN.The Pt1@MSN can realize the imaging of cytoplasm in living cells.2.Synthesis of phosphorescent iridium(III)complex containing p-aminophenol groups and the response to the hypochloriteIr1,a phosphorescent probe for hypochlorite,was designed and synthesized by introducing p-aminophenol groups into the iridium complex.Its structure was characterized by 1H NMR and mass spectrometry,and its photophysical properties were studied by UV-vis absorption spectrum and fluorescence emission spectrum.Complex Ir1 exhibited a yellow-green emission with the maximum emission peak located at 521 nm.With the gradual addition of hypochlorite,the p-aminophenol groups in the complex Ir1 would be removed with 4-iminocyclohexa-2,5-dienone,and the phosphorescence emission of complex Ir1 gradually decreased until quenching,and the "turn-off" detection of hypochlorite was realized.In addition,complex Ir1 exhibited good selectivity to the hypochlorite.