1,3,5-triaryl-2-pyrazoline Derivatives Probes For Metal Ions:Synthesis And Poperties Investigation

Molecular fluorescent probe is an indispensable means of detection in modemscience research, which has the advantages of high sensitivity、small sample amount、quick response and other characteristics. With the rapid development of the scienceand technology, progress in synthesis and application of molecular fluorescent probehas been promoted, and the research on organic fluorescent compounds is of currentinterest.It is worthy of note that pyrazoline derivatives have been reported to show broadrange of biological activities, such as antibacterial, anti-inflammatory, analgesic,anti-high blood pressure, anti-depressant, anti-TB, anticancer and so on. Furthermore,it has displayed high quantum yield and hole-transporting efficiency, therefore,pyrazoline derivatives have been used not only as fluorescent sensors for recognitionof metal ions，but also as organic light-emitting diodes and novel fluorescentmaterials.In view of the importance of pyrazoline derivatives in pharmaceuticals andfluorescent materials fields, we focused our attention on the synthesis and opticalproperties research of pyrazoline derivatives and the exploration of fluorescent sensorbased on pyrazoline moiety.We outlined the theoretical significance of molecular fluorescent probe andsummarized the latest national and international work in the beginning of this article.And then, learnt from the known results and related literature, we have designed andsynthesized three novel pyrazoline derivatives. Meanwhile, the interaction of threesmall molecule substances with metal ions was investigated using UV-Visibleabsorption spectroscopy combined with fluorescence spectroscopy. The following arethe main results:1. Synthesis of three novel1,3,5-Triaryl-2-pyrazoleline derivatives andinvestigate poperties by¹HNMR and¹³CNMR andHRMS.2. The chalcone derivatives was investigated of absorption spectra andfluorescence spectra. At the same time， spectra of compound3in eigthsolvents（petroleum ether, CH₂Cl₂, CH₃COOC₂H₅, CH₃COCH₃, CH₃CN, CH₃OH,CH₃CH₂OH, THF） with different poarerty have been investigated. It was respectively studied to metal ions fluorescent probe of compound3a,3b and3c, compound3c bychoose ethanol and acetonitrile as solvent. This compound3c in ethanol solution wasinvestigated by metal ions probe, it was found that3c had better selectivity to Cu²⁺,this compound in acetonitrile solution was investigated by different metal ions probe,it was found that selectivity for3c was not ideal, the three compounds of chalconehave not reached to demand the metal ions probe fluorescence probe.3. The pyrazoline derivatives was explored of metal ion fluorescence probe, thepyrazoline compounds had three substituents of the electron-donating group （methoxygroup）, but also electron-withdrawing group （methyl group） in this thesis, the threecompounds in acetonitrile/water （1:1,v/v） as the solvent can identify and responseCu²⁺, they had distinct fluorescence quenching，the Cu²⁺ion for on the fluorescencequenching of efficiency of three compounds were: compound4a was about48times,compound4b was24times, compound4c80was times, the selection specificity ofthem were better. Comparison of three pyrazoline compounds, compounds4c wasaffected by other metal ions with minimal disturbance in metal ion probes, that of itwas to Cu²⁺probe specificity best choice to achieve the required high selectivityfluorescent probe, rapid response, the small sample size and other characteristics. Forthe latter use of such a pyrazoline derivative fluorescent probe molecules detected canbe detected with high selectivity Cu²⁺ions provide a theoretical basis in theenvironment, biomedical technology and other fields. It could also supply moreinformation in researching highly selective fluorescent probe molecules and detecting transitionmetals, heavy metals, and some toxic substances basis at very low concentration.