共查询到20条相似文献,搜索用时 15 毫秒
1.
We have developed a Cd2+ fluorescent chemosensor with high selectivity as well as sensitivity by tethering a 4,7-bis(2-hydroxyethyl)-9-hydroxy-1,4,7-triazanonyl chelator to anthracene. This sensor features the ability to discriminate Cd2+ from Zn2+ to a high degree (KdZn/KdCd = 560) in a pH 7.2 buffer. 相似文献
2.
Sukhdeep Kaur 《Tetrahedron letters》2004,45(26):5081-5085
Fluorescent chemosensor 3 can sense Cu2+ ions (1-8 μM) even in the presence of elevated levels of Ni2+, Cd2+, Zn2+, Hg2+, Ag+ and Pb2+ (5000 μM). 3 can also analyze for Ag+ ions (50-500 μM) in the presence of Ni2+, Cd2+, Zn2+, Hg2+ and Pb2+ (5000 μM) but Cu2+ strongly interferes. 相似文献
3.
Xiuli Wang Wenyan Zheng Hongyan Lin Guocheng Liu Yongqiang Chen Jiani Fang 《Tetrahedron letters》2009,50(14):1536-5286
An intramolecular charge transfer (ICT) chromophore 2-(2-pyridine)imidazo [4,5,f]-1,10-phenanthroline (1) has been synthesized and firstly used as a chemosensor with a reversible, ‘on-off’ sensing capability for biologically and environmentally significant Co2+ in DMF under buffered conditions. The experiment results also show that the response behavior of 1 to Co2+ is pH independent in range of pH 3.0-7.0 and show excellent selectivity for Co2+ over other cations. 相似文献
4.
Hanna GohMin Joung Kim Preeti SalujaNarinder Singh Doo Ok Jang 《Tetrahedron letters》2012,53(30):3900-3902
A dipodal receptor was synthesized by condensation of isophthalaldehyde and p-toluenesulfonylhydrazide. The receptor was found to be selective for Cu2+ recognition in CH3CN. The resultant Cu2+ receptor complex selectively recognized iodide through cation displacement assay in a CH3CN/H2O (8:2, v/v) solvent system. 相似文献
5.
A new selective Zn^2+ fluorescent chemosensor, o-vanillin-4-ethoxybenzoylhydrazone (1), was designed and prepared. Free 1 mainly displayed very weak fluorescence at 480 nm upon excitation at 403 nm. It displayed high selectivity for Zn^2+ and had a 518- fold fluorescent enhancement upon binding of Zn^2+, while the other cation ions had only little influence on the fluorescence of 1. Mechanism of enhancement of l's fluorescence by Zn^2+ was briefly discussed. 相似文献
6.
The Cu(I)-catalyzed azide-alkyne cycloaddition reaction (CuAAC) has been used to synthesize an anthracene-based fluorescent compound that undergoes strong fluorescence quenching in the presence of Cu(II). Fluorescence studies indicate that the compound forms a 1:1 complex and can be used to quantitatively determine micromolar concentrations of Cu(II) in aqueous solution. 相似文献
7.
Xu Tang Juan Han Yun Wang Liang Ni Longhua Li Lei Wang Wenli Zhang 《Tetrahedron》2017,73(10):1367-1373
A new on-off fluorescent probe 1 for Cu2+ based on Schiff base compound was designed and synthesized by one-step reaction. The single probe 1 exhibited strong green fluorescence emission. A fluorescence quenching effect and faint color change were observed as soon as the Cu2+ was added to the probe system in H2O/EtOH (v/v = 8:2, HEPES buffer, 0.05 M, pH = 7.4) solution. Other common metal cations did not cause the changes in the fluorescence and color of the probe 1. The optical properties were studied by the fluorescence emission and UV–Vis spectra. Meanwhile, the geometry optimizations of probe 1 and the [1-Cu2+] coordination complexes were also carried out by DFT using the Gaussian 09 program, in which the B3LYP function was used. Based on experimental measurement and theoretical analysis, we can know that the combination ratio of the probe and Cu2+ is 2:1 and the limit of detection (LOD) is as low as 5.3 × 10?9 M Besides, the probe 1 was also used to analyze the Cu2+ in living cells. 相似文献
8.
9.
Mao Xiang Wang Xiang Ming Meng Man Zhou Zhu Qing Xiang Guo 《中国化学快报》2007,18(11):1403-1406
A novel fluorescence enhancement Cu~(2 ) chemosensor derived from coumarin was prepared.Emission study found that it exhibits evident Cu~(2 )-amplified fluorescence prior to Co~(2 ),Pb~(2 ),Mg~(2 ),Mn~(2 ),Ni~(2 ),Zn~(2 ),Fe~(3 ),Ag~ and Cd~(2 ),and the largest emission enhancement factor is about 9 at a ratio of 2:1 (chemosensor 1/Cu~(2 )). 相似文献
10.
Compound 1 was facilely synthesized through a one step reaction from commercially available materials. As a sensitive and selective “turn-on” fluorescent chemosensor for Zn(II), 1 exhibits a 40-fold fluorescence enhancement response to Zn(II) over other physiological relevant metal ions in aqueous solution at neutral pH. Furthermore, 1 could be efficiently delivered to live cells for bioimaging of Zn(II). 相似文献
11.
A simple highly sensitive and selective turn-on fluorescent chemosensor L based on bis-Schiff-base for Pb2+ ions was synthesized and characterized by spectroscopic techniques. L having high binding affinity towards Pb2+ ions of 2.10 × 104 M?1 selectively detects Pb2+ ions with almost no interference among various competitive ions by a 11-fold fluorescent enhancement in CH3CN/H2O (95:5, v/v) solution over a wide pH range. Moreover, sensor L displayed a lower detection limit of 3.80 × 10?7 M, which is low enough for sensing sub-millimolar concentration of Pb2+ encountered practically. 相似文献
12.
A highly selective and sensitive rhodamine-based colorimetric chemosensor (1) for quantification of divalent copper in aqueous solution has been investigated in this work. It was designed using salicylaldehyde hydrazone and rhodamine 6G as copper-chelating and signal-reporting groups, respectively. In environmentally friendly media (50% (v/v) water/ethanol and 10 mM NaAc–HAc neutral buffer (pH 7.0)), the sensor exhibited selective absorbance enhancement to Cu2+ over other metal ions at 529 nm, with a dynamic working range of 0.05–5.00 μM and a detection limit of 10 nM Cu2+, respectively. To achieve fluorometric determination of Cu2+, the Cu2+-induced absorbance enhancement of 1 was efficiently converted to fluorescence quenching by fluorescence inner filter effects using rhodamine B (RB) as a fluorophore. The selectivity and sensitivity of fluorescence analysis were similar to those of absorptiometric measurement. Both absorptiometric and fluorometric methods were successfully applied to the detection of Cu2+ in three water samples. 相似文献
13.
A new fluorescent chemosensor based on an acyclic tetra-sulfonamide derivative linked to two dansyl groups has been conveniently synthesized. Its high selective binding ability to fluoride ions over other halide ions was demonstrated by using fluorescence as well as 1H NMR spectra. 相似文献
14.
Conditional stability constants for the Cu-sensitive fluorescent dye Phen Green™ SK (PGSK) were determined for complexes containing both Cu(I) and Cu(II). Experimental conditions were optimized to minimize oxidation of Cu(I) to Cu(II). A binding constant of 1011.38 for PGSK and Cu(I) was determined using chloride as the competing ligand and an iterative procedure involving equilibrium calculations to fit experimental data. The new constant was tested by evaluating PGSK fluorescence in the presence of the strong Cu(I)-ligand neocuproine and thiourea. There was good agreement between experimental data and changes in fluorescence predicted by calculations using the new constant and published constants for the competing ligands. Using EDTA to buffer the free ion concentration of Cu2+, the conditional stability constant of PGSK with Cu(II) was measured to be 109.8. Both of these new constants are significantly higher than previously published values. Finally PGSK was used to examine the kinetics of Cu(I) dissociation from the biologically important ligand glutathione. 相似文献
15.
Kyung Beom Kim Dong Min You Jun Hwi Jeon Yo Han Yeon Jong Ha Kim Cheal Kim 《Tetrahedron letters》2014
We have synthesized a new Schiff base 1, which detects Al3+ through fluorescence and naked eye in aqueous solution. The sensor 1 exhibited selective and sensitive recognition toward Al3+ via significant fluorescence enhancement (31-fold). Moreover, it showed a significant color change from colorless to yellow. The complex formation was proposed to be 1:1 ratio, based on the Job plot, ESI-mass spectrometry analysis, 1H NMR titration, and IR analysis. The detection limit was 1.00 μM, which is below the WHO acceptable limit (1.85 μM) in drinking water. In addition, the sensor 1 could be recyclable simply through treatment with a proper reagent such as EDTA. 相似文献
16.
A novel fluorogenic receptor 1 was prepared by the reaction of thiosemicarbazide with 1-naphthaldehyde. Based on in situ-formed 1-Fe(III) complexes having the specific binding affinity for F− anions, this sensory system allows rapid recognition and quantitative detection of fluoride in neutral aqueous media in an ‘off-on’ fashion. The fluoride measurement method not only exhibits a low detection limit but also has strong anti-interference ability to common coexisting ions, as evidenced by competitive experiments. 相似文献
17.
A new rhodamine-based chemosensor was synthetized through a modified copper-catalyzed [3+2]-cycloaddition of an azidocoumarin with an alkynyl-rhodamine. Its sensing properties toward various metal cations in aqueous solutions were investigated by colorimetric changes, UV–vis and fluorescence spectroscopies. The sensor exhibited a high selectivity for Cr2+ over Cr3+ and other divalent cations such as Cu2+, Mg2+, Zn2+, Ca2+, Cd2+, Co2+, Hg2+ and Ni2+. The linear range of detection by fluorescence spectroscopy is 0.07–3.5 mM, with a detection limit of ca. 64 μM. The binding mode of Cr2+ with the sensor was rationalized through experimental evidences. 相似文献
18.
A new tri-imidazolium salt, tris(4-(3-(2-((8-hydroxy-9,10-dioxo-9′,10′-dihydroanthracen-1-yl)oxy)ethyl)-1H-imidazole-3′-ium-1′-yl)phenyl)amine hexafluorophosphate was prepared and characterized. Particularly, the recognition performance of the tri-imidazolium salt for cations was investigated through fluorescence and ultraviolet titrations, MS, IR spectra and 1H NMR titrations. The results indicated that the tri-imidazolium salt can distinguish effectively copper(II) ion from other cations by the changes of spectroscopy and colour (from yellow to orange under sunlight). Furthermore, the tri-imidazolium salt was also used in detecting Cu2+ through employing smartphone with the computed detection limit down to 0.51 μM. 相似文献
19.
Two N-pyrenylacetamide-substituted sugar-aza-crown ethers have been synthesized as new fluorescent chemosensors. The designed ligands 1 and 2 exhibit fluorescence characteristics of a pyrene monomer and a dynamic excimer emission when compared to N-pyrenylacetamide as a model compound. Both ligands displayed a Cu2+-sensitive fluorescence quenching with a 1:1 stoichiometry and high stability constants (log K = 6.7 for 1 and 7.8 for 2). The quenching effect was rationalized on the basis of photoinduced electron transfer from the excited pyrene to the complexed Cu2+ cation, while the changes in excimer-to-monomer ratio were explained by a conformational analysis through DFT calculations. The predicted structure suggests that the Cu2+ cation is coordinated with the two carbonyl groups and the sugar-aza-crown ethers which rigidified the complex structure and placed the two pyrene moieties far apart. 相似文献
20.
A novel 8-hydroxyquinoline derivative 3 was synthesized. Significant fluorescent quenching was found in the presence of Cu2+ and Hg2+ with notably higher selectivity for Cu2+ than Hg2+. 相似文献