新型三脚架苯甲醛苯腙醋酸根选择性比色化学传感器

本文合成了一个新的基于三脚架苯甲醛苯腙的能够选择地检测醋酸根离子的比色化学传感器1。用紫外可见吸收光谱证实了受体1在二甲基亚砜溶液中对醋酸根离子高选择的键合能力超越了其它阴离子。和其他所研究的阴离子相比,其在二甲基亚砜中紫外可见吸收光谱对具有高选择性醋酸根离子的存在显示了应答,当存在（2´10^-5mol·dm^-3）醋酸根离子时其溶液的颜色也由黄色变化到蓝色。当用其他不同的客体阴离子（F^-, Cl^-, Br^-, I^-, H₂PO₄ ^–和 OH^-）处理受体1时,仅出现了很小的紫外可见吸收光谱变化。受体1对醋酸根的结合常数 K_ass为1.69´ 10⁴。     

Carboxylate anion selective receptor with glycoluril molecular scaffold

Glycoluril based tweezer-type receptor has been designed and synthesized. Anion binding studies carried out using ¹H NMR and UV-vis revealed that this compound displays good affinities for Y-shaped anions such as acetate and benzoate, while binding spherical-shaped anions and tetrahedral-shaped anions only weakly.     

A simple naphthalene-based colorimetric sensor selective for acetate

A new naphthalene based receptor (L) has been designed and synthesized which shows a remarkable color change from colorless to pink on selective binding with acetate. The anion recognition property of the receptor via hydrogen bonding interactions is monitored by UV-vis, fluorescence, and ¹H NMR titrations. It is observed that in each case, the receptor shows a specific selectivity toward the acetate ion over other interfering anions. Thus, a significant bathochromic shift in UV-vis spectrum with a sharp pink color in ‘naked-eye’ makes the receptor suitable for the detection of the acetate ion.     

A chloride selective sensor based on a calix[4]arene possessing a urea moiety

New calix[4]arene derivative 1 of 1,3-alternate conformation with a ureido moiety has been synthesized in high yield and examined for its anion recognition abilities towards anions such as fluoride, chloride, bromide, iodide, nitrate and acetate by ¹H NMR and UV-vis spectroscopy. The results show that receptor has strong binding affinity for chloride ions. A chloride ion selective electrode (ISE) was also formed which showed excellent selectivity over all the other anions tested. The limit of detection is 2.51 × 10⁻⁵ mol dm⁻³.     

Colorimetric ��naked-eye�� sensor for anions based on conformational flexible tripodal receptor

A new tripodal receptor for anion sensing based on amide-pyridinium as recognition site and nitro-benzene as signaling unit was designed and successfully synthesized. This receptor showed high selectivity and strong binding affinity toward AcO^? over the investigated anions, especially over H₂PO₄ ^?. Addition of AcO^? induced clear color change of solution from colorless to yellow, realizing the ??naked-eye?? detection. UV?CVis and ¹H NMR experiments indicated the selectivity might origin from the synergistic effects arising from hydrogen bonding, electrostatic interactions and conformational change.     

Potentiometric response and mechanism of anionic recognition of heterocalixarene-based ion selective electrodes

The ion selective electrode (ISE)-based potentiometric approach is shown to be an effective means of characterizing the anion recognition sites in the molecular receptor calix[2]pyridino[2]pyrrole (CPP). In particular, potentiometric pH-measurements involving the use of experimental PVC-membranes based on CPP revealed the existence of both mono- and diprotonated forms of the receptor under readily accessible conditions. Based on these analyses, apparent surface protonation constants for this heterocalixarene were found to lie between 8.5-8.9 (pK_B1) and 3.3-3.8 (pK_B2). CPP was found to interact with targeted anionic analytes based on both coulombic and hydrogen bond interactions, as inferred from varying the kinds of ionic sites present within the membrane phase. Potentiometric selectivity studies revealed that CPP preferred “Y-shaped” anions (e.g. acetate, lactate, benzoate) over spherical anions (e.g. fluoride and chloride), fluoride over chloride within the set of spherical anions, and the ortho-isomer over the corresponding meta- and para-isomers in the case of hydroxybenzoate (salicylate and congeners). In the context of this study, the advantages of potentiometric determinations of acetylsalicylic acid using optimized PVC-membranes based on CPP relative to more conventional PVC-membrane ISEs based on traditional anion exchanger were also demonstrated.     

Triphenylamine-based simple chemosensor for selective fluorometric detection of fluoride, acetate and dihydrogenphosphate ions in different solvents

Triphenylamine-based new chemosensors 1 and 2 have been designed and synthesized for fluorometric detection of anions. The urea-amide conjugates in 1 and 2 are involved in binding of anions via hydrogen bonding. UV?Cvis and fluorescence titration experiments revealed that the sensor 1 has the selectivity for acetate (AcO^?), dihydrogenphosphate (H₂PO₄ ^?) and fluoride (F^?) over the other anions examined in the present study, in CHCl₃. In comparison, receptor 2 is non responsive for the same anions under similar conditions. In more polar solvent CH₃CN containing 0.1% DMSO, the receptor 1 shows a greater selectivity towards fluoride. The color of the solution of 1 is changed from colorless to light yellow and finally to yellowish brown only in the presence of fluoride in CH₃CN containing 10% DMSO. In pure DMSO and CH₃CN solvents, almost colorless solution of 1 is transformed into blood red and reddish brown in the presence of 30 equivalent amounts of F^?, respectively.     

Retention of anions on silica-based metalloporphyrin stationary phases.

The silica-based Fe(III)-protoporphyrin and Zn-tetraphenylporphyrin stationary phases were examined for the HPLC separation of anions. The retention of nine common inorganic anions as well as benzoate anion (BA) and its hydroxy analogues (HBA) was examined using tartrate, acetate, and succinate eluents. The retention factors of inorganic anions on the FeProP stationary phase were in the order Cl- < NO3- < ClO4- < I- < SCN- and for organic anions benzoate < p-hydroxybenzoate < m-hydoxybenzoate < o-hydroxybenzoate. The retention factors of organic anions examined for a ZnTPP column were in the order p-HBA < m-HBA < BA < o-HBA.     

Effect of spacer geometry on oxoanion binding by bis- and tetrakis-thiourea hosts

Hosts with thiourea groups bind anions by formation of multiple hydrogen bonds. This contribution discusses how spacers linking two or four thiourea groups affect the host affinity and selectivity. While most of the bis-thioureas bind H₂PO₄⁻ preferentially, the extent of selectivity over chloride, acetate, and H₂AsO₄⁻ is determined by the size of the binding cavity. A tetrakis-thiourea is shown to exhibit a unique H₂AsO₄⁻ selectivity, and the discrimination of chloride is enhanced by specific solvation in dimethyl sulfoxide.     

铽配合物Tb(PMIP)3(PhCA)的合成及阴离子识别研究

本文设计合成了稀土铽配合物Tb(PMW)3(PhCA)作为阴离子试剂,利用荧光光谱考察了其与F-、Cl-、Br-、I-、ClO4-、NO3-、AcO-和H2PO-4等阴离子的作用.研究结果表明:不同阴离子的加入能够调控,Tb(PMIP)3(PhCA)的发光行为,当一定量的氟离子(醋酸根离子、磷酸二氢根离子)加入到Tb(PMIP)3(PhCA)的乙腈溶液中后,荧光发射增强;过量的氟离子(醋酸根离子、磷酸二氢根离子)加入后则使其荧光淬灭.而在乙腈和水混合溶液中,Tb(PMIP)3(PhCA)则能选择性识别氟离子和磷酸二氢根离子.     

Anion binding by pyrrole–pyridine-based macrocyclic polyamides

The synthesis, characterisation and anion-binding properties of new pyrrole–pyridine-based macrocyclic polyamides 7a and 7b are presented. Chloride anion templation in the macrocyclisation reaction has been shown to control [1 + 1] acylation. The anion-binding properties of the receptors have been determined by UV–vis titrations in a DMSO solution and compared with systems with a similar design. The new receptors have been found to display a 10-fold selectivity for hydrogensulphate, dihydrogenphosphate and acetate anions over other anions studied.     

Amide-based Fluorescent Macrocyclic Anion Receptors

Introduction Interest in the selective recognition and sensing of anionic species continues to attract the attention of su-pramolecular chemistry community.1 The importance of anions in chemical and biological process can not be underestimated. It is well known that in nature neutral proteins bind anions only via hydrogen bonding interac-tions.2 Several anion receptors have been constructed from five-membered heterocycle,3 amide,4 (thio) urea,5 since these groups form relatively strong NHanio…     

Cu(II) complex of an abiotic receptor as highly selective fluorescent sensor for acetate

A copper complex having quinoline moiety as fluorophore has been synthesized. The anion recognition behavior of the receptor and its copper complex has been studied in acetonitrile and in acetonitrile: H₂O (95:5 v/v). The copper complex shows high selectivity toward acetate over other anions studied such as F⁻, Cl⁻, Br⁻, I⁻, OAc⁻, dl-malate, l-mandelate, benzoate, isophthalate, , and .     

The potentiometric performances of cyclotetrahydroxysiloxane containing ferrocenyl moiety as an anion-selective membrane electrode

A test electrode based on cyclotetrasiloxane containing ferrocenyl, hydroxide and amine moiety exhibits very good potentiometric performance toward anions. Especially, acetate ion shows non-Hofmeister behavior on selectivity. The addition of the tetraalkylammonium salt provides lipophilic cationic sites within the membrane and enhances the response to more lipophilic anions. As expected, potentiometric performances of slopes and detection limits for the most of lipophilic anions, such as ClO₄⁻ and SCN⁻, are the most enhanced. However, the response to acetate ion was significantly decreased. In our knowledge, this is the first report that cyclic siloxane containing functional groups such as ferrocenyl moiety and hydroxyl group shows possible usage as a neutral carrier for an anion sensor.     

Nickel Pyrazolyl Borate Complex: Synthesis,Structure, and Analytical Application as Benzoate Selective Sensor

The complex [Tp^Ph,MeNi(Cl)Pz^Ph,MeH] ( I ) [Tp^Ph,Me=hydrotris(3‐phenyl‐5‐methyl‐pyrazol‐1‐yl)borate; Pz^Ph,MeH=3‐phenyl‐5‐methyl‐pyrazole] has been synthesized and explored as ionophore for the preparation of a poly(vinyl chloride) (PVC) membrane sensor for benzoate anions. The formation constants for the interaction of complex I with different organic/inorganic anions in solution have also been studied by sandwich membrane method. PVC based membranes of I using tridodecylmethylammonium chloride (TDDMACl) as cation discriminator and o‐nitrophenyloctyl ether (o‐NPOE), dibutylphthalate (DBP), benzylacetate (BA) and tributylphosphate (TBP) as plasticizing solvent mediators were prepared and investigated as benzoate selective sensors. The best performance was shown by the membrane with composition (w/w) of I (5): PVC (150): NPOE (345): TDDMACl (0.3). The proposed sensor exhibits significantly enhanced selectivity toward benzoate ions over the concentration range 2.2×10^?6–1.0×10^?1 M with a lower detection limit of 1.4×10^?6 M and a Nernstian slope of 59.2 mVdecade^?1 of activity within a pH range of 4.5–8.5. The sensor has a response time of 12 s and can be used for at least 8 weeks without any considerable divergence in their potential response. The membrane sensor of complex I have been checked for reversible and accurate sensing of benzoate levels present in liquid food products.     

Visible Colorimetric Sensor for Fluoride Ion Based on o-Phenylenediamine

A new chromogenic receptor based on 1,2-phenylene derivative containing thiourea moieties is synthesized and examined for its anion binding ability by UV–Vis and ¹H NMR studies. The results show that the receptor has selective colorimetric sensing of fluoride over all other anions like chloride, bromide, iodide, nitrate, hydrogen sulphate and acetate.     

Reactivity of α-Amino Acids in the Reaction with Esters in Aqueous–1,4-Dioxane Media

The kinetics of the reaction of a series of α-amino acids with 4-nitrophenyl acetate, 4-nitrophenyl benzoate, and 2,4,6-trinitrophenyl benzoate in aqueous 1,4-dioxane medium has been studied. Kinetics of the reactions involving 4-nitrophenyl acetate and 2,4,6-trinitrophenyl benzoate has complied with the Brønsted dependence and revealed linear correlation between rate constant logarithm and the energy difference of the frontier orbitals of α-amino acids anions.     

Thiazole-based chemosensor III: synthesis and fluorescence sensing of CH3CO2 based on inhibition of ESIPT

Novel fluorogenic sensors based on urea derivative of 2-(2′-aminophenyl)-4-phenylthiazole (4 and 5) were prepared and used for recognition of anions with similar basicity and surface charge density. Chemosensor 4 was found to be highly selective to acetate ion over other anions. The selectivity was related to the structure matching between the host and the guest. The evaluation of the chemosensors’ interaction with anions was performed by UV-vis and fluorescence titration. This acetate binding affinity was further tuned by varying the acidity of the N-H proton of the urea moiety in chemosensor 5.     

Benzoate ion-selective electrode with improved selectivity and reproducibility for benzoate determination in medicinal syrups

This paper describes the construction and evaluation of a benzoate anion selective electrode with enhanced working characteristics, namely reproducibility and selectivity, to be used in medicinal syrups analysis by direct potentiometry. The electrode, without an internal reference solution, was prepared with a PVC membrane, based onbis(triphenylphosphoranylidene) ammonium benzoate as ion-exchanger, dissolved in 2-nitrophenyl octyl ether as mediator solvent and 4-t-octylphenol as additive. The characteristics of the electrodes were evaluated in sodium benzoate solutions with adjusted ionic strength and showed a linear response in the range 10^–2–2 × 10^–4 mol dm^–3 with a slope of 54.7 ± 0.5 mV/decade and a reproducibility of ±0.2 mV/day for solutions with pH 6.3. The potentiometric selectivity coefficients were determined for some possible interfering species and showed that the electrodes prepared with the additive had good selectivity, especially over iodide and nitrate, when compared with those without any additive. The electrodes were used for benzoate determinations in several medicinal syrups by direct potentiometry. The results gave recovery values in the range 98.3–104.6%.     

Study on Synthesis and Binding Ability of a New Anion Receptor Containing NH Binding Sites

A new colorimetric recognition receptor 1 based on the dual capability containing NH binding sites of selectively sensing anionic guest species has been synthesized. Compared with other halide anions, its UV/Vis absorption spectrum in dimethyl sulfoxide showed the response toward the presence of fluoride anion with high selectivity, and also displayed dramatic color changes from colorless to yellow in the presence of TBAF （5 × 10^-5 mol/L）. The similar UV/Vis absorption spectrum change also occurred when 1 was treated with AcO^- while a little change with H2PO^-4 and OH^-. Receptor 1 has almost not affinity abilities to Cl^-, Br^- and I^-. The binding ability of receptor 1 to fluoride with high selectivity over other halides contributes to the anion size and the ability of forming hydrogen bonding. While the different ability of binding with geometrically triangular （AcO^-）, tetrahedral （H2PO^-4 ） and linear （OH^-） anions maybe result from their geometry configuration.