Synthesis of an anion receptor for acetate based on the frame of ferrocene

An anion receptor was synthesized with ferrocene as binding frame. Anion recognition can be monitored by anion complexation-induced changes in UV-vis absorption spectra. Interaction between the receptor and acetate was described on the basis of 1H NMR experiments

A simple colorimetric sensor for biologically important anions based on intramolecular charge transfer (ICT)

A sensitive colorimetric sensor (1) based on 4,5-dinitrobenzene-1,2-diamine was designed and synthesized. Binding of anions such as AcO(-), F(-) and H(2)PO(4)(-) results in a notable change in the visible region of spectrum (an approximately 90 nm red shift), which can be detected by the 'naked-eye'. Furthermore, the binding ability was evaluated by UV-vis titration experiments as following: AcO(-) > F(-) > H(2)PO(4) >> Cl(-), Br(-), I(-). The nature of the color change of I induced by AcO(-) was due to the intramolecular charge transfer (ICT) which was confirmed by X-ray crystal structure and (1)H NMR titration spectra. (c) 2009 Elsevier B.V. All rights reserved

A novel coumarin-based switching-on fluorescent and colorimetric sensor for F-

A novel turn-on fluorescent and colorimetric sensor, N-(4'-nitrophenyl)-2-oxo-6-(phenylazo)2H-chromene-3-carbohydrazide (1), for fluoride in dimethyl sulfoxide (DMSO) was designed and synthesized. The binding ability evaluated by UV-vis and fluorescence titration experiments reveals that I can selectively recognize fluoride. In particular, addition of F- to the DMSO solution of I resulted in an enhancement in fluorescence intensity at 338 and 352 nm, which can provide a way of 'naked-eye' detection for fluorides. The spectral change of I is due to the anion-induced increase of the charge density in and the rigidity of the host molecule. Furthermore, the binding mode with F- was investigated by H-1 NMR experiments. (C) 2008 Elsevier B.V. All rights reserved

Study on the selectivity of anion receptors by adjusting the distance of two urea fragments and their analytical application

Three anion receptors based on urea: 1 N, N'-bis-(p-nitrophenylaminocarbonyl)-Hydrazine, 2 N, N'-bis-(p-nitrophenylaminocar-bonyl)-ethylenediamine and 3 N, N'-bis-(p-nitrophenylaminocarbonyl)-1, 3-propane-diamine are designed and synthesized. Studies of UV-vis spectra presented that 1 was an excellent sensor of F- and 2 was sensitive to H2PO4 (-). Unfortunately, 3 can not distinguish the anions investigated in this paper. The color changes of the hosts upon the addition of a variety of structurally different anions were also utilized as naked-eye detection which is very convenient. It also revealed significantly that the distance between two recognition sites of receptor had an immediate effect on the selectivity of receptor for anions, which had been confirmed by the H-1 NMR titration and IR

Study on optical recognition and electrochemical sensing of a 1,1 '-ferrocenedicarbonylhydrazine derivative for fluoride

A new compound, 1,1'-di-(p-nitrophenylhydrazino-beta-carbonyl)-ferrocene (1) was designed as an anion receptor based on its hydrogen bonding interaction with anions. Investigation of UV-vis spectra showed that it was an excellent optical sensors for F-. Furthermore, the nature of interaction between it and F- was investigated by H-1 NMR titration experiments. In addition, the efficiency of the receptor applied as an electrochemical sensor for F- was discussed by cyclic voltammetry (CV). Copyright (C) 2008 John Wiley & Sons, Ltd

An optical and electrochemical anion sensor of F- investigated by UV-vis, H-1 NMR and cyclic voltammetry

A new anion receptor: 1,1'-di-(2',4'-di-nitrophenylhydrazino-beta-carbonyl)-ferrocene (1) based on ferrocene has been designed and synthesized as a highly colorimetric and electrochemical sensitive sensor for F-. The binding mode with F- was further investigated by UV-vis titration and 1H NMR titration experiments. In addition, the cyclic voltammetry (CV) was performed to discuss the electrochemical sensing for F-

A novel, simple, colorimetric receptor based on 2 ',4 '-dinitrophenylhydrazone for acetate ion in organic medium

A novel 1,3-di(2',4'-dinitrophenylhydrazone)-5-nitrobenzene receptor has been synthesized by simple steps with good yields. The anion recognition properties were studied by ultraviolet-visible (UV-Vis) spectroscopy. The results showed that the receptor had a higher affinity to F-, CH3COO- and H2PO4 (-), but no evident binding with Cl-, Br-, and I-. Upon addition of the three former anions to the receptors in dimethyl sulphoxide (DMSO) at 298.2 +/- A 0.1 K, the solution exhibited an obvious color change from yellow to mauve that could be observed by the naked eye, thus the receptor could act as a fluoride ion sensor even in the presence of other halide ions. The UV-Vis data indicates that a 1:1 stoichiometry complex formed through hydrogen-bonding interactions between receptor and anions. The hydrogen bond between phenylhydrazone -NH and acetate or fluoride anion was determined on the basis of H-1 nuclear magnetic resonance (NMR) experiments

An Efficient Novel Acetate Anion Receptor based on Isatin

An anion recognition receptor, a kind of thiourea derivative, was designed and synthesized by combining indoline-2,3-dione and 1,3-diaminothiourea. The anion recognition can be easily monitored by anion complexation induced changes in UV-vis absorption spectra. In particular, the binding ratio between the receptor and fluoride is 1:2 but in the case of dihydrogenphosphate and acetate are 1:1. Moreover, the affinity constants revealed that the receptor can recognize acetate well. Finally, H-1 NMR experiments were carried out to explore the nature of interaction between this new receptor and acetate

A high selective anion colorimetric sensor based on salicylaldehyde for fluoride in aqueous media

A new and simple salicylaldehyde-based sensor 1 designed for fluoride sensing has been investigated in DMSO and even in the 9/1 DMSO/H(2)O (v/v) Mixtures. The affinity constants of receptor 1 for anionic species in the 9/1 DMSO/H(2)O (v/v) reveal that it is sensitive to F. Also, the color changes induced by anions can provide a way of detection by 'naked-eye'. These result can be substantiated by the spectrum changes upon the addition of 25 equiv. anions to 1 in the 9/1 DMSO/H(2)O solution. The further insights to the nature of interactions between the sensor 1and F were investigated by (1)H NMR titration experiments in 9/1 DMSO-d(6)/H(2)O (v/v). In addition, the proposed binding mode between 1 and F(-) was suggested. (C) 2009 Elsevier B.V. All rights reserved

A novel colorimetric receptor responding AcO- anions based on an azo derivative in DMSO and DMSO/water solution

A novel and efficient receptor based on the phenylhydrazone derivatives is successfully developed and applied to the acetate anion recognition, indicating that the origin of special preference for acetate (AcO-) anion maybe the structure well matching between the host and the guest. The sensor changes its color so obviously on addition of the acetate ions and that may make the naked-eye recognition in DMSO and even in DMSO/H2O (95/5) solution come true. Also, the anion binding ability determinations were performed by UV-vis titration and H-1 NMR titration experiments with different anions in the solutions mentioned. The fluorescence enhancement can also be observed after the host is coordinated with the AcO- anion and excited by light wavelength at 280 nm. (C) 2009 Elsevier B.V. All rights reserved