共查询到20条相似文献,搜索用时 15 毫秒
1.
Jinli Zhu Yuhuan Zhang Yihan Chen Tongming Sun Yanfeng Tang Yang Huang Qingqing Yang Danyang Ma Yipu Wang Miao Wang 《Tetrahedron letters》2017,58(4):365-370
A simple Schiff base CTS, synthesized between 2-hydroxy-1-naphthaldehyde and 2-benzylthio-ethanamine, was found to be a good turn-on fluorescence probe for the detection of Zn2+, due to the restriction of the rotation of the bond between CN and naphthalene ring and/or the blocking of the photo-induced electron transfer (PET) mechanism of the nitrogen atom to naphthalene ring. Excellent selectivity for Zn2+ was evidenced, over many other competing ions, including Fe3+, Cr3+, Ni2+, Co2+, Fe2+,Mn2+, Ca2+, Hg2+, Pb2+, Cu2+, Mg2+, Ba2+, Cd2+, Ag+, Li+, K+, and Na+, in EtOH/HEPES buffer (95:5, v/v, pH = 7.4). It was noteworthy that Cd2+ had no interference with Zn2+. The stoichiometric complex of CTS-Zn2+ was determined to be 2:1 for CTS and Zn2+ in molar, based on the Job plot and single crystal X-ray diffraction data. The binding constant of the complex was 85.7 M?2 with a detection limit of 5.03 × 10?7 M. The fluorescence bio-imaging capability of CTS to detect Zn2+ in live cells was also studied. These results indicated that CTS could serve as a favorable probe for Zn2+. 相似文献
2.
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
3.
Chemosensor based on Schiff base molecules (1, 2) were synthesized and demonstrated the selective fluoro/colorimetric sensing of multiple metal ions (Mn2+, Zn2+ and Cd2+) in acetonitrile–aqueous solution. Both 1 and 2 showed a highly selective naked-eye detectable colorimetric change for Mn2+ ions at 10−7 M. Fluorescence sensing studies of 1 and 2 exhibited a strong fluorescence enhancement (36 fold) selectively upon addition of Zn2+ (10−7 M, λmax = 488 nm). Fluorescence titration and single crystal X-ray analysis confirmed the formation of 1:1 molecular coordination complex between 1 and Zn2+. Interestingly, a rare phenomenon of strong second turn-on fluorescence (190 fold, λmax = 466 nm) was observed by the addition of Cd2+ (10−7 M) into 1 + Zn2+ or Zn2+ (10−7 M) into 1 + Cd2+. Importantly both 1 and 2 exhibited different fluorescence λmax with clearly distinguishable color for both Zn2+ and Cd2+. 相似文献
4.
A simple Schiff base type fluorescent receptor was prepared and evaluated for its fluorescence response to heavy metal ions. Receptor exhibits an "off-on-type" mode with high selectivity in the presence of Zn(2+) ion. The addition of EDTA quenches the fluorescence of receptor -Zn(2+) complex, making receptor a reversible chemosensor. The selectivity of for Zn(2+) is the consequence of combined effects of CHEF, C[double bond, length as m-dash]N isomerization and inhibition of ESIPT. 相似文献
5.
Fluorescence probes NA1 and NA2 derived from 1-naphthylamine (NA) as fluorophore have been synthesized and characterized by different spectroscopic studies. Identification behaviour of these probes towards various metal ions has been investigated. Both the fluorescent probes are selective as well as sensitive towards Fe(III) ion. Novel fluorescence probe NA2 afforded turn-on fluorescence behaviour for Fe(III) ion over other metal ions such as Ca(II), Mg(II), Mn(II), Fe(II), Co(II), Fe(III), Ni(II), Cu(II), Zn(II) and Hg(II). 相似文献
6.
Anil K. Singh Nirmalya Majumdar 《Journal of photochemistry and photobiology. B, Biology》1995,30(2-3):105-113
All-trns-N-retinylidenetryptamine Schiff base was incorporated into aerosol-OT (AOT, sodium bis(2-ethylhexyl)sulphosuccinate)/heptane reverse micelles. This micellar system was used as a model to study the retinal-tryptophan interactions in retinal proteins. The retinylidene Schiff base remains stable in the presence of reverse micelle-solubilized water pools. Partition coefficient and microviscosity measurements show that the Schiff base is located in the micellar interphase. The results are discussed in terms of the interaction between the retinylidene chromophore and the active site environment of rhodopsin and bacteriorhodopsin. In the present model, the quencher and emitting units are covalently attached, and are separated by two carbon spacer units. The fluorescence emission data obtained for the micelle-intercalated Schiff base chromophore are compared with the fluorescence of the native protein and intermediates in the photochemical cycle of bacteriofhodopsin. A comparison of the data obtained for tryptamine and the Schiff base with the results available for bacteriorhodopsin and bacterioopsin reveals that there is a large degree of quenching on intercalation of the retinylidene chromophore in the vicinity of the fluorophore. Evidence provided by this model suggests that energy transfer to retinal can occur from tryptophan residues located in the retinal pocket in the native protein. Thus the retinylidene unit can act as a quencher of the energy of tryptophan, the nature and extent of which may depend on the conformation and relative orientation of the protein-bound fluorophore. 相似文献
7.
《印度化学会志》2023,100(4):100985
A Schiff base ligand L has been designed and synthesized by the condensation of 1′-Hydroxy-2′-acetonaphthonehydrazide with pyrene aldehyde for the detection of Cu2+ ions. The ligand was spectroscopically characterized by all possible techniques. Among different metal ions, Cu2+ ions give a tremendous enhancement of fluorescence intensity in 20% water with THF. The “Turn-On” fluorescence for Cu2+ ions utilizes the Photo-induced Electron Transfer (PET) mechanism. It has been observed that the presence of relevant cations and anions did not affect the probe's fluorescence intensity. The stoichiometric binding mode of the complex is confirmed using Job's method. The low detection limit and reversibility make it cost-effective. 相似文献
8.
Xinjing Wang Dan Shi Yimang Xu Shanshan Yu Feng Zhao Yachen Wang Lingling Hu Jun Tian Xiaoqi Yu Lin Pu 《Tetrahedron letters》2018,59(24):2332-2334
An amino-acid based Schiff base (S)-2 is prepared from the condensation of (S)-3,3′-diformyl BINOL (BINOL?=?1,1′-bi-2-naphthol) with l-valine in the presence of tetrabutylammonium hydroxide in methanol. This compound is found to exhibit off-on-off fluorescence response toward Zn2+. The spectroscopic studies reveal that (S)-2 reacts with 1 equiv Zn2+ to form a dimeric [2+2] complex with greatly enhanced fluorescence. Excess amount of Zn2+ might cause dissociation of this dimeric complex to give significantly reduced fluorescence. 相似文献
9.
《Arabian Journal of Chemistry》2014,7(5):609-614
Novel heterocyclic Schiff base dyes were prepared by the reaction of salicylaldehyde/2-Hydroxy-1-naphthaldehyde with different heterocyclic amines. Results of the newly synthesized compounds established by FT-IR, 1H-NMR, 13C-NMR and GC–MS spectroscopic experiments were consistent with their chemical structures. Resulted heterocyclic Schiff base dyes were found to be pure from data obtained by the elemental analysis. In addition, spectrophotometric and spectrofluorimetric studies showed that these dyes were good absorbent and fluorescent. Fluorescence polarity study data revealed that some of these compounds were sensitive to the polarity of the microenvironment provided by different solvents. Time-based fluorescence steady-state measurements also showed that these heterocyclic Schiff base dyes have high photostability against photobleaching. 相似文献
10.
A turn-on fluorescent probe, based on a water-soluble terphenyl derivative, for the detection of cysteine and homocysteine is reported. The aldehyde groups in the probe play crucial roles in providing reaction with thiol groups in the amino acids, leading to a formation of thiazolidine (from cysteine) or thiazinane ring (from homocysteine). As a result, the new formation of such rings alters the electronic property of the conjugated system in the probe and results in emission enhancement. The probe in aqueous solution exhibits a remarkable increase in its quantum yield upon exposure to cysteine (up to 20-fold) and to homocysteine (up to 700-fold), while slight quenching is observed in the presence of glutathione. Moreover, an investigation on time-resolved fluorescence spectra of the probe in the presence of cysteine and homocysteine reveals potential discriminatory detection of cysteine and homocysteine. Bioimaging of the thiols in live HeLa cells was successfully applied. 相似文献
11.
12.
Erting Feng Ruimin Lu Congbin Fan Chunhong Zheng Shouzhi Pu 《Tetrahedron letters》2017,58(14):1390-1394
A new fluorescent turn-on chemosensor for Al3+ based on a diarylethene unit was designed and synthesized. Photochromism, fluorescence switch, and metal ion recognition behaviors of this diarylethene derivative were investigated by absorption and fluorescence emission spectra. It shows an outstanding fluorometric sensing ability toward Al3+ ion, and the detection limit was measured to be 9.3 × 10?8 mol L?1 via fluorescence methods. Based on these interesting properties, a combinational logic circuit was constructed successfully. 相似文献
13.
Dong-dong Qin Zheng-yin Yang Gao-fei Qi 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,74(2):415-420
The synthesis of three Paeonol Schiff base ligand and their Zn(II) complexes are reported. The complexes were fully characterized by IR, 1H NMR, elemental analysis and molar conductivity. The experiment results show the three Zn(II) complexes can emit bright fluorescence at room temperature in DMF solution and solid state. The fluorescence quantum yields (Φ) of three Schiff base ligands and their Zn(II) complexes were calculated using quinine sulfate as the reference with a known ΦR of 0.546 in 1.0N sulfuric acid. Furthermore, in order to develop these Zn(II) complexes’ biological value, the antioxidant activities against hydroxyl radicals (OH) were evaluated. The results show the three complexes possess excellent ability to scavenge hydroxyl radicals. 相似文献
14.
Milan Jakubek Zdeněk Kejík Václav Parchaňský Robert Kaplánek Liudmila Vasina Pavel Martásek 《Supramolecular chemistry》2017,29(1):1-7
A novel water-soluble chromone Schiff base derivatives bearing polyhydroxylated moiety were prepared and applied for specific recognition of metal ions in aqueous medium. Their selective fluorescence response to Al(III) over a variety of other biologically important metal ions were demonstrated. Electronic parameters of the sensors were also studied by quantum chemical computations. 相似文献
15.
We report the synthesis of {[3-(biscarboxymethylamino)-2-methoxy-5-methylphenyl]carboxymethylamino}acetic acid, which functions as a Zn2+ selective fluorescence probe (sensor). 相似文献
16.
《印度化学会志》2023,100(4):100957
Coumarinyl-benzothiazolyl Schiff base (HL) is spectroscopically (FTIR, UV–Vis, NMR, Mass) characterized and the Single Crystal X-Ray Diffraction measurement confirms the structure. The molecule is water insoluble and DMSO solution shows weak emission which may be due to ESIPT assisted H-transfer quenching process. The emission is significantly enhanced in presence of CN−, one of the most toxic anions, through ‘turn-on’ emission (λem = 449 nm; λex = 350 nm) even in presence of many other anions. The mechanism of sensing towards CN− has been described by 1H NMR titration which reveals deprotonation of –OH group and nucleophilic attack to the imine (-CHN-) bond. Further, the Job's plot supports 1:1 molar binding ratio, [HL + CN−] (Kd, 0.696 x 104 M−1) and has been confirmed by ESI-MS. The detection limit (LOD), 0.75 μM, is third best literature. MTT assay of HL shows no-toxicity up to 100 μM and Intracellular Imaging in MDA-MB 231 cell line has been performed for the sensing of CN−. 相似文献
17.
The carbazole derivative, 9-ethyl-3-carbazylidene carbazole hydrazone (ECCH) with two conjugated carbazole rings have been applied as a fluorescence carrier for preparation of an iodine sensitive optical chemical sensor. The response of the sensor is based on quenching of the fluorescence of ECCH by iodine. The conjugated carbazole dimer based sensor shows a linear response toward iodine in the concentration range 1.0 × 10−6 to 1.0 × 10−4 mol L−1, with a detection limit of 8.0 × 10−7 mol L−1 at pH of 7.0. The effect of composition of the sensor membrane was studied, and the experimental conditions were optimized. Most commonly coexisting ions do not interfer with the iodine assay. The sensor shows sufficient repeatability, selectivity, operational lifetime of two months and a fast response of less then 50 s. The sensor has been used for determination of iodine in water samples. 相似文献
18.
A sensitive fluorescence turn-on method for trace amounts of uranyl ion (UO22+) in solution has been developed in this study, based on aggregation induced emission enhancement (AIEE) characteristics of 4-pethoxycarboxyl salicylaldehyde azine (PCSA) induced by complex interaction between UO22+ and PCSA. Under optimized conditions, a fluorescence enhancement at 540 nm could be observed, which was linearly related to the concentration of UO22+ in the range of 1–25 ppb (part per billion). Analytical data showed that a detection limit of 0.2 ppb was achieved with the relative standard deviation (R.S.D.) 1.3% (n = 5). The proposed method was successfully utilized in quantifying UO22+ in fuel processing wastewaters. 相似文献
19.
N,N′,N″,N′′′-1,5,8,12-tetraazadodecane-bis(salicylaldiminato)(H2L) has been used as ionophore for preparing Mn2+ selective sensor. Membranes of different composition with regard to ratio of H2L:PVC:NPOE:NaTPB have been prepared and investigated. The best performance was obtained with the membrane of composition 10:150:150:10 (H2L:PVC:NPOE:NaTPB) (w/w; mg). This membrane generated linear potential response in the concentration range of 5.0 × 10−6 to 1.0 × 10−1 M with a Nernstian slope of 30.0 mV/decade of activity and fast response time (10 s). Hydrogen ion does not effect to the performance of sensor in the pH range 3.0-6.5. The sensor was found to be sufficient selective for Mn2+ over a number of alkali, alkaline and heavy metal ions and could therefore be used for the determination of manganese in various samples by direct potentiometry. 相似文献
20.
Functional zinc(II) phthalocyanines bearing Schiff base complexes as oxidation catalysts for bleaching systems 下载免费PDF全文
Oxidation catalysis is used to increase the performance of hydrogen peroxide in laundry bleach applications. Bleach catalysts provide cost‐effective, energy‐saving and environmentally friendly bleach systems yielding perfect stain removal at lower temperatures. This comparative study is based on the synthesis of bis[bis(salicylhydrazonephenoxy)manganese(III)] phthalocyaninatozinc(II) ( 2 ), bis[bis(salicylhydrazonephenoxy)cobalt(III)] phthalocyaninatozinc(II) ( 3 ) and bis[bis(salicylhydrazonephenoxy)iron(III)] phthalocyaninatozinc(II) ( 4 ) as tri‐nuclear complexes consisting of two Schiff base complexes substituting a zinc phthalocyanine. Complexion on the periphery to obtain complexes 2 , 3 , 4 was performed through the reaction of a Schiff base‐substituted phthalocyanine using MnCl2?4H2O, CoCl2?6H2O or FeCl3?6H2O salts in basic condition in dimethylformamide. Fourier transform infrared, 1H NMR, 13C NMR, UV–visible, inductively coupled plasma optical emission and mass spectra were applied to characterize the prepared compounds. The bleach performances of the three phthalocyanine compounds 2 , 3 , 4 were examined by the degradation of morin as hydrophilic dye. The degradation progress in the presence of catalysts 2 , 3 , 4 /H2O2 combination in aqueous solution was investigated using an online spectrophotometric method. It was found that the catalysts 2 , 3 , 4 exhibited better bleaching performance at 25 °C than tetraactylethylethylenediamine as bleach activator used in powder detergent formulations for stain removal. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献