| Today fluorescent chemosensors have been the hot research focus because of its high sensitivity and selectivity, easy on-site analysis and low detection limit. The five-membered heteroaromatic 1,2,3 triazole compounds are synthesized by Cu(I)-catalyzed azide/alkyne cycloaddition(CuAAC) which is often said “click”reaction. Due to “click” reaction mild reaction conditions, high yield, fast synthesis reaction and easy availability of raw materials and reaction reagent, it has been widely concerned in the field of supramolecular. The N atom of the 1,2,3 triazole compounds can be coordinated with the metal ion, and the 5- bit CH can form hydrogen bond with the anion. Accordingly, 1,2,3 triazole compounds can be used as a chemical sensor for the recognition of cations or anions by rational chemical modification. Series of dipodia or tripodia compound triazole compounds with pyrene or pyrene as fluorophores was synthesised by “click” reaction and the coordination properties of these compounds with cations and anions have been characterized by the methods of fluorescence emission spectroscopy, UV-visible absorption spectroscopy and 1HNMR. The details are as follows:A new three-armed triazole receptor 2-1 based on anthracene as fluorophore which is centering on benzene have been synthesized and characterized. In acetonitrile aqueous solutions, 2-1 showed good fluorescence “turn-off” sensing ability to Hg2+ over other metal ions. 1HNMR analysis revealed that 3-N atoms of triazole rings and O atoms of the ether bond of receptor 2-1 plays a critical role in the interaction with mercury ion.The three(triazole) amine compounds 3-1 based on anthracene as fluorophore has been synthesized from tripropargylamine and anthracene azide using Cu(I)-catalyzed click chemistry. In acetonitrile/Tris-HCl(1:1, v/v, pH= 7.2) buffer solutions, 3-1 showed fluorescence turn-off response to Ni2+over other metal ions.The detection limit for Ni2+ is 7.1 × 10-7 M.The pyrene sulfonamide receptor 4-1, 4-2, 4-3, 4-4, 4-5 and 4-6 centering on benzene were synthesized by “Click” reaction. In acetonitrile solution, due to thedifferent structural cavity size of receptor 4-1, 4-2, 4-3, 4-4, 4-5 and 4-6, the receptors showed different fluorescence changes for H2PO4-. The compounds 4-1, 4-3 and 4-5show fluorescence ratio change for H2PO4- with the monomer emission intensity enhancing and the excimer emission intensity decreasing. monomer emission intensity of the compounds 4-2 and 4-4 are basically unchanged and excimer emission intensity are quenching. Compared with the pincer compounds 4-1 and 4-3,three-armed compound 4-5 have better sensitivity to H2PO4- owning to more binding sites. In addition, due to the deprotonation of F-, the compounds 4-1, 4-2, 4-3, 4-4, 4-5and 4-6 all showed fluorescence quenching.Novel triazolium-based anion receptors(1a-1d) bearing pyrene fluorphore with different alkyl chain have been have been designed and synthesized. In aqueous solution, the compounds 1c and 1d can be selective recognition of ATP based on induced receptor π-π conjugated self-assembly. The receptors 1a and 1b could not be selective recognition of ATP, which showed that the length of the alkyl group affected the recognition of ATP and the self-assembly process. In addition, through dynamic light scattering(DLS) experiments, we verified the self-assembly process of the receptor 1d via binding ATP. |
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