Chemosensors For Anions Research Articles

ChemInform Abstract: Recent Advances in 1,10‐Phenanthroline Ligands for Chemosensing of Cations and Anions

AbstractReview: 242 refs.

Several hemicyanine dyes as fluorescence chemosensors for cyanide anions

Four hemicyanine dyes as chemosensors for cyanide anions were synthesized easily. Their photophysical properties and recognition properties for cyanide anions were investigated. The results indicate that all the dyes can recognize cyanide anions with obvious color, absorption and fluorescence change. The recognition mechanism analysis basing on in situ 1H NMR and Job plot data indicates that to the compounds with hydroxyl group, the recognition mechanism is intramolecular hydrogen bonding interaction. However, to the compounds without hydroxyl group, cyanide anion is bonded to carbon–carbon double bond in conjugated bridge and induces N+CH3 to neutral NCH3. Fluorescence of the compounds is almost quenched upon the addition of cyanide anions.

A modest colorimetric chemosensor for investigation of CN- in semi-aqueous environment with high selectivity and sensitivity

Two nobel, modest and easily forming anion chemosensors (B1/B2) based on azo linked Schiff base were designed and synthesized. The chemosensors displays large extent of selectivity toward CN− and lesser for AcO− resulting instant color change expressions witnessed in 10% aqueous medium. The limit of detection diagnosed for CN− ion is down to 0.478/1.66μM that is below the WHO level. The anion binding property of the chemosensor via deprotonation mechanism is monitored by hydroxyl and 1H NMR titration. The coated paper test strips is served as mini colorimetric device for finding of CN− in aqueous solution. It can be practiced for quantitative assurance of CN− concentrations in water samples.

DFT/TD-DFT calculations on the sensing mechanism of a dual response near-infrared fluorescent chemosensor for superoxide anion and hydrogen polysulfides: photoinduced electron transfer

Fluorescence quenching by the PET process in HCy-FN.

3-Hydroxyflavone derivatives synthesized by a new simple method as chemosensors for cyanide anions

Two 3-hydroxyflavone derivatives as chemosensors for cyanide were synthesized by one step simple condensation, cyclization and subsequent oxidation reaction catalyzed by pyrrolidine, which shows great convenience compared with traditional method.

A “turn on” fluorescent and chromogenic chemosensor for fluoride anion: experimental and DFT studies

A simple, convenient “turn on” fluorescent and chromogenic chemosensor for fluoride anion detection in acetonitrile as well as in water has been developed.

Applications of Reactive Chemosensors for Anion

Applications of Reactive Chemosensors for Anion

28]Hexaphyrin derivatives for anion recognition in organic and aqueous media.

Hexaphyrin-based anion chemosensors are reported for the first time. The meso-hexakis(ethylenediamine)-substituted [28]hexaphyrins 2 and 3 revealed strong affinity for F(-), AcO(-) and H2PO4(-). Adsorption constants in aqueous media were determined on a gold piezoelectric crystal coated with 2 and 3. (1)H NMR titrations and molecular dynamics simulations showed the main interactions between hosts and guests.

A fluorescent coumarin-thiophene hybrid as a ratiometric chemosensor for anions: Synthesis, photophysics, anion sensing and orbital interactions

A colorimetric and fluorimetric fluorescent chemosensor (CT-2), having a coumarin ring as a signaling unit and an acetamido thiophene ring as an H-donor receptor, has been synthesized from amino derivative (CT-1) of CT-2 for the purpose of recognition of anions in DMSO. The absorption and emission maxima were both determined for the fluorescent dye in different solvents. Both hypsochromic shift at the absorption maximum, and quenching of fluorescence after interactions between the anions and the receptoric part, were observed. This phenomenon was explained using orbital interactions based on quantum chemical calculations. The selectivity and sensitivity of CT-2 for F−, Cl−, Br−, I−, AcO−, CN−, H2PO4−, HSO4− and ClO4− anions were determined with spectrophotometric, fluorimetric and 1H NMR titration techniques and it was found that CT-2 be utilized for the detection of CN−, F− and AcO− in the presence of other ions as competitors. Color and fluorescence changes visible to the naked eye and under UV (365 nm) were observed upon addition of CN−, F− and AcO− to the solution of chemosensor (CT-2) in DMSO. The sensor showed no colorimetric and fluorimetric response for the anions such as Cl−, Br−, I−, H2PO4−, HSO4−, and ClO4−. However, 1H NMR titration shows that the chemosensor was more sensitive to CN−, than F− and AcO− at the stochiometric ratio of 1:2.5 respectively. Additionally, the compounds CT-1 and CT-2 showed good thermal stability for practical applications.

Polypyridyl-imidazole based Os(II) complex as optical chemosensor for anions and cations and multi-readout molecular logic gates and memory device: Experimental and DFT/TDDFT study

A monometallic Os(II) complex of composition, [(bpy)2OsII(phen-Hbzim-tpy)](ClO4)2, where phen-Hbzim-tpy=2-(4-(2,6-di(pyridin-2-yl)pyridine-4-yl)phenyl)-1H-imidazole[4,5-f] [1,10]phenanthroline and bpy=2,2′-bipyridine, containing a free terpyridine site for cationic guest and an imidazole moiety for the anionic guest, has been designed for the fabrication of multifunctional logic circuits. This complex acts a red-color emitter and effective bifunctional optical chemosensor for F− and CN− as well as Fe2+ and Cu2+ ions. The anion and cation sensing properties of the metalloreceptor have been thoroughly investigated in solution through different channels such as absorption, steady state and time-resolved emission spectroscopic methods and by square wave voltammetric technique. On the basis of the absorption, emission and electrochemical responses with specific set of anionic and cationic inputs, the present metalloreceptor finds its ability to mimic the logic functions of two-inputs INHIBIT, IMPLICATION, and OR logic gate as well as four inputs NOR logic behavior. Moreover, the complex can mimic sequential Boolean logic functions capable of integrating into “Writing–Reading–Erasing–Reading” combinational circuit for molecular-level information processing. To gain a deeper insights about the structural as well as spectral aspects of the complex, theoretical calculations have also been performed employing density functional theory (DFT) and time-dependent density functional theory (TD-DFT).

Anthraimidazoledione-Terpyridine-Based Optical Chemosensor for Anions and Cations That Works As Molecular Half-Subtractor, Key-Pad Lock, and Memory Device

We designed in this work a new family of anthraquinone and imidazole functionalized bifunctional terpyridine receptor, 2-(4-(2,6-di(pyridine-4-yl)phenyl)-1H-anthra[1,2-d]imidazole-6,11-dione (tpy-HPhImz-Anq) for recognition and sensing of selective anions and cations as well as for the construction of multifunctional logic devices. The terpyridine motif in the receptor was utilized for the cation coordination site and the imidazole moiety as the anion binding site. Both anion and cation recognition aspects of the receptor were thoroughly investigated in acetonitrile, mixed DMSO–water, as well as in solid media via different optical channels such as absorption, steady state, and time-resolved emission spectroscopic techniques. On the basis of the absorption and emission spectral responses toward a specific set of ionic inputs, this unique bifunctional receptor can mimic several advanced logic functions such as those of half-subtractor, key-pad lock, and memory device. We also report the implementation of t...

Sensitive water-soluble fluorescent chemosensor for chloride based on a bisquinolinium pyridine-dicarboxamide compound

The new fluorescent dicationic compound, N,N′-bis(N-benzyl quinolinium)pyridine-2,6-dicarboxamide triflate 1, was synthesized and studied as a chemosensor for inorganic anions in water. At pH 5.0 chloride quenches the blue fluorescence of 1 (the Stern–Volmer constant KSV=380) and forms a very stable complex with receptor (KA=5050M−1). A photoinduced electron transfer quenching mechanism with simultaneous receptor-chloride complexation both in the excited and the ground state is proposed. On basis of 1H NMR and UV–vis titrations, ESI-MS experiments, crystal structure and DFT calculations, the binding mode of Cl− is proposed involving two hydrogen bonding interactions N–H···Cl− with simultaneous formation of two short C–H···Cl− contacts inside the cleft of 1 formed by pyridine-dicarboxamide motif; these interactions are favored by complementarity of the cleft to chloride anion. The efficient binding is attributed to strong acidification of NH and CH donors by quaternization of quinolyl groups. The receptor 1 allows the fluorescence detection of chloride in water with a detection limit of 33μmolL−1 and good selectivity over other common anions such as bromide, phosphate, pyrophosphate and acetate.

A turn-on fluorescent sensor for detection of cyanide in aqueous media

2-Hydroxy-1-naphthaldehyde oxime (receptor 1) serves as a selective chemosensor for cyanide anion (CN−). In the presence of CN−, an enhanced fluorescent intensity and red-shift were observed. The observed complexation between receptor 1 and CN− may cause by a hydrogen bonding interaction between the OH group of receptor 1 and CN−.

Coumarinic chalcone derivatives as chemosensors for cyanide anions and copper ions

Four coumarinic chalcone derivatives were synthesized via typical condensation reaction between 4-(hydroxyl)coumarinketone and 4-(diethylamino)-benzaldehyde or 7-(diethylamino)coumarinaldehyde in good yields. Their crystal structures and recognition properties for cyanide and copper ions were investigated. The results indicate that the compounds exhibit quick and obvious color and fluorescence response to the ions with high sensitivity and selectivity in acetonitrile. Mechanism studies suggest that cyanide group is possibly bonded to 4-position of coumarin group or the α carbon atom of CC bridge. Coordinate between the compounds and copper ions forms.

Coumarin amide derivatives as fluorescence chemosensors for cyanide anions

Four coumarin amide derivatives with 4-methyl coumarin or pyrene as terminal group have been synthesized. Their photophysical properties and recognition properties for cyanide anions have been examined. The results indicate that the compounds can recognize cyanide anions with obvious absorption and fluorescence spectra change, at the same time, obvious color and fluorescence change can be observed by naked eye. The in situ hydrogen nuclear magnetic resonance spectra and photophysical properties change confirm that Michael additions between the chemosensors and cyanide anions take place at the 4-position of coumarin.

Novel chemosensor for multiple target anions: The detection of F− and CN− ion via different approach

Abstract A novel chemosensor based on azo linked Schiff base (receptor 1 ) was synthesized by simple condensation method. The sensor studies of receptor 1 disclose the selectivity toward fluoride and cyanide ion with a color change among the other common anions in aqueous medium. The binding affinity of receptor 1 was also enlightened by 1 H NMR titration and DFT calculation.

A peptide-based fluorescent chemosensor for multianalyte detection.

A novel multifunctional peptide fluorescent chemosensor (DP-3) with a lysine backbone and double sides conjugated with histidine and dansyl groups has been designed and synthesized by solid phase synthesis. This chemosensor is a promising analytical tool for detecting Zn(2+), Cu(2+), and S(2-) based on different mechanisms in 100% aqueous solutions, and intracellular biosensing has been successfully actualized. The peptide beacon structure of DP-3 makes it more stable and capable of achieving multianalyte detection, especially for sulfide ions. Until now, there have been few examples of using a peptide fluorescent chemosensor to detect anions with a continuous method. As designed, DP-3 exhibits excellent cell permeation and low biotoxicity and displays high selectivity and sensitivity, with Zn(2+) and Cu(2+) detection limits of 82 nM and 78 nM, respectively. This study raises the new possibility of a highly selective peptide fluorescent chemosensor for multifunctional detection, including cation and anions, by different mechanisms in environmental and biological systems. We expect that this work will inspire the development of a multifunctional beacon peptide-based fluorescent chemosensor library using modifiable lateral and terminal groups for a variety of practical applications in physiological and pathological events.

A reversible dual-channel chemosensor for fluoride anion

A colorimetric and fluorescent fluoride probe bearing phenolic hydroxy and imine groups has been designed and synthesised. This receptor could visually and spectroscopically recognise F− with high selectivity over other anions. After the addition of fluoride ions to the solution of ([1,1′-biphenyl]-4,4′-diylbis (azanylylidene)) bis (methanylylidene)) bis (naphthalen-2-ol) (TY), since the deprotonation reaction occurred between the sensor and fluoride, the fluorescence intensity of the solution changed significantly. Furthermore, the quenched fluorescence caused by fluoride ions could be recovered upon the addition of calcium ions to this complex solution. This resulted in an ‘OFF-ON-OFF’ type sensing. In particular, an IMP logic gate has been proposed using the output obtained from the fluorescence studies. The fluorescence, UV-vis titration and 1H NMR titration experiments indicated that the effects might occur via a combined process including hydrogen bond and deprotonation between the sensor and F− .

Sulfonamide and urea-based anions chemosensors

The detection of anions has attracted considerable interest because of their importance in various physiological processes. In this study, two sulfonamide and urea-based compounds (1a and 1b) were successfully developed and their spectroscopic and anion recognition properties were fully investigated. These results showed that: (1) compounds showed high selectivity towards cyanide and fluoride ions in CH3CN; (2) compounds only exhibited a large change in fluorescence in the presence of cyanide ions in CH3CN–H2O (95:5, v/v); and (3) compound 1b could act as a gel in dimethyl sulfoxide that transforms into a homogeneous solution upon exposure to cyanide ions. This research suggests that sulfonamide and urea can act as hydrogen-bond donors and provides an alternative approach to the design of novel anion chemosensors.

Coumarin benzothiazole derivatives as chemosensors for cyanide anions

Four coumarin benzothiazole derivatives, N-(benzo[d]thiazol-2-yl)-2-oxo-2H-chromene-3-carboxamide (1), (Z)-N-(3-methylbenzo[d]thiazol-2(3H)-ylidene)-2-oxo-2H-chromene-3-carboxamide (2), 7-(diethylamino)-N-(benzo[d]thiazol-2-yl)-2-oxo-2H-chromene-3-carboxamide (3) and (Z)-7-(diethylamino)-N-(3-methylbenzo[d]thiazol-2(3H)-ylidene)-2-oxo-2H-chromene-3-carboxamide) (4), have been synthesized. Their crystal structures, photophysical properties in acetonitrile and recognition properties for cyanide anions have been investigated. All the compounds are generally planar, especially compound 1 exhibits perfect planarity with dihedral angle between benzothiazolyl group and coumarin group being only 3.63°. Coumarin benzothiazole compounds 1 and 3 can recognize cyanide anions by Michael addition reaction and compound 3 exhibits color change from yellow to colorless and green fluorescence was quenched completely, which can be observed by naked eye. Coumarin benzothiazolyliden compound 4 can recognize cyanide anions with fluorescence turn-on response based on the copper complex ensemble displacement mechanism.