Synthesis And Characterization Of New Triazolophanes For Recognition Of Anions And Cations

The 1,2,3-triazoles obtained by click reaction have attracted much attention for its simple reaction condition, high yield, no by-products and simple separation, and have been applied in chemical, pharmaceutical, environmental and materials science. In addition, macrocyclic receptors also have got much attention for their preorganization and size compatibility with the guest, and are a hot topic in supramolecular chemistry. Herein, we synthesized and characterized a series of macrocyclic triazoles and their acyclic compared compounds, and investigated their anions or cations recognition abilities by UV-Vis specrtra, emission spectra and electrochemical techniques, and their binding mechanism are also investigated by 1H NMR titration and DFT calculations.1. A new naphthalene-containing macrocyclic triazole L1 and its acyclic compared compound L2 have been synthesized and characterized. In acetonitrile and acetonitrile aqueous solutions, L1 and L2 showed good fluorescence sensing ability to Hg2+ over other metal ions, with L1 exhibiting better sensitivity and selectivity than L2 owing to its macrocyclic effect. 1H NMR titrations and DFT calculation results showed that the N atoms of triazole and O atoms of the ether groups in L1 and L2 participate in binding during complexation with Hg2+.2. A new triazolephan receptor L3 bearing binaphthol fluorophore and ferrocene electrochemical singling site has been synthesized by “Click reaction”. Among various metal ions, L3 shows exclusive multiple singles sensing of Zn2+ in CH3 CN solution. Upon the addition of Zn2+, the fluorescence of L3 exhibited a red shift from 380 nm to 430 nm with enhancement the emission intensity. In addition, the Fc+/Fc reversible redox potential of L3 was shifted from 430 mV to 480 mV. Fluorescence titration, 1H NMR titrations and DFT calculation results reveal that the N atoms of triazole and O atoms of the ether groups take part in binding in L3-Zn2 + complexation with forming 1:1 complex.3. Two new ferrocene-containing macrocyclic triazoles L4 and L5 and their acyclic compared compounds L6 and L7 were synthesized by click reaction, and their anions recognition abilities were investigated by CVs and DPVs techniques. Among various anion(F-,CI-,Br-,I-,CH3COO-,H2PO4-), all receptors show distinctive sensing of H2PO4- with a large negative shift of their electrochemical potential. 1H NMR titration results reveal that the triazole CH of receptors take part in binding with H2PO4-, and the macrocyclic recptor show stronger binding ability than the acyclic compare compound.