Design,Synthesis And Properties Of Fluorescence Probes Containing Triphenylimidazole And BODIPY Derivatives

Fluorescent probes play a vital role in the detection for environmental and biological species.They can be utilized to recognize heavy metal cations including copper ions,mercury ions,barium ions,lead ions,etc.,various anions?cyanide ions,hydrogen sulfite ions,nitrite ions,etc.?and small molecules?hydrogen peroxide,glutathione,cysteine,etc.?.Fluorescent probes have gained rapid development owing to their speciality,simplicity and low cost in the passed decades.However,the high sensitivity,excellent selectivity and good water solubility of the fluorescent probes are still challenge.In this dissertation,three fluorescent probes containing triaryl imidazole and/or fluoroboron derivatives were successfully designed and synthesized.Some representative results are as following:?1?Design,synthesis and cyanide ion detection performance of the fluorescent probe Mcy.Mcy was prepared by the Knoevenagal condensation between 4-?4,5-diphenyl-1H-imidazol-2-yl?benzaldehyde and potassium 5-sulfono-2,3,3-trimethyl-1-?3-sulfonatepropyl?-3H-indolium and its molecular structure was fully characterized by ¹H NMR,¹³C NMR and MALDI-TOF mass spectroscopy.The response of MCy towards CN^-in HEPES buffer?pH 7.4?was investigated by UV-Vis and fluorescence spectroscopy.Upon the addition of CN^-,the emission band located at 443 nm dramatically increased and the color changed from colessless to bright blue under a UV lamp.Good linear relationships between fluorescent intensity and CN^-concentrations in the range of 0-40?M was observed and a minimum detection limit of 20.6 nM was achieved.The Job's titration indicated that the probe reacted with cyanide ions in a 1:1 stoichiometry.Additionally,the probe was successfully applied to detect cyanide ion in the MCF-7 cells.?2?Synthesis and properties of fluorescent probe TPIP containing triphenyl imidazole motif for Cu²⁺detection.The probe TPIP was synthesized by dehydrogenative cross-coupling between 4-?4,5-diphenyl-1H-imidazole-2-yl?benzaldehyde and 2-aminopyridine under the catalysis of CuI.The molecular structure of TPIP was elucidated by ¹H NMR,¹³C NMR and MALDI-TOF mass spectroscopy.With the addition of Cu²⁺,the fluorescence emission peak at 436 nm gradually decreased and good linearity was obtained between fluorescence intensity and Cu²⁺concentration.The minimum detection limit of the probe TPIP was calculated to be 19.6 nM.The detection mechanism of TPIP to Cu²⁺was verified to be a 2:1 binding mode by Job's fluorescence titration.Moreover,the probe TPIP coated silica gel plate was successfully applied to monitor Cu²⁺in a facile way.?3?Synthesis and properties of the probe BODIPY-P for hypochlorous acid detection.The probe BODIPY-P was synthesized in DMF using BODIPY-2 and CH3I as raw materials and its molecular structure was fully characterized by ¹H NMR,¹³C NMR and MALDI-TOF mass spectroscopy.Upon the addition of NaClO to BODIPY-P,the green emission peak at 567 nm dramatically enhanced while almost retained the red emission peak at 629 nm,and the ratio of fluorescence intensity(F₅₆₇/F₆₂₉)was linear correlated with HClO concentration in the range of 0-5 eq.The detection limit was estimated to be 31.6 nM.More importantly,the probe was low toxic and could effectively visualize exogenous and endogenous HClO in living cells.