Novel N,N＇-Diacylhydrazine-Based Colorimetric Receptors for Selective Sensing of Fluoride and Acetate Anions

Three novel and simple N,N＇-diacylhydrazine-based colorimetric receptors have been prepared. The binding properties of the receptors to anions such as F^-, Cl^-, Br^-, AcO^-, HSO4^- and HEPO4^- in acetonitrile solution were examined by UV-Vis spectroscopy methods, which show high sensitivity and selectivity to F^- and AcO^- over other anions. The results indicated that a 1 ： 1 stoichiometry complex was formed between the receptors and the anions, while ^1H NMR titrations confirmed hydrogen binding interaction between the receptors and the anions.     

Anion Recognition Using Novel and Colorimetric Tweezer Receptors:1,3-Phenylenedi(carbonylhydrazone) in Aqueous-organic Binary Solvents

本文设计合成了2种新型的间苯二甲酰腙类钳形受体。在DMSO和DMSO-H2O混合溶液中,通过紫外可见光谱分别考察了受体分子3a对F-, Cl-, Br-, I-, AcO-, HSO4-, H2PO4-和ClO4-的相互作用。结果表明,在DMSO溶液中,受体3a对F-,CH3COO-和H2PO4-有显著识别效果,溶液颜色由无色变为黄色,实现裸眼检测。在15%H2O-85%DMSO含水体系中,3a可高选择性识别CH3COO-。1H NMR滴定表明过量F-的加入使受体分子3a发生脱质子作用,探讨了主客体之间的作用机理。并直接用于水相中无机醋酸盐的直接显色检测。     

基于分子内电荷转移的阴离子比率荧光分子探针

设计合成了一种基于4-甲基-1-羟基二苯甲酮对硝基苯腙的比色和比率荧光阴离子受体1。此类受体以羟基和腙单元为识别位点,以硝基苯基为信号报告基团。向受体1的DMSO溶液中加入AcO-、H2PO4-、F-后,溶液颜色由黄色变为紫红色,而加入所研究的其它阴离子则无变化,从而实现对AcO-、H2PO4-、F-这三种离子的裸眼识别。利用紫外-可见吸收光谱、荧光光谱考察了其与AcO-,H2PO4-,F-,Cl-,Br-,I-等阴离子的识别作用。1H NMR滴定为受体分子与阴离子之间氢键作用本质提供了有力证据。     

Novel Hydrazone‐Based Tripodal Sensors: Single Selective Colorimetric Chemosensor for Acetate in Aqueous Solution

A series of novel tripodal colorimetric anion sensors based on hydrazone CHN NH groups have been synthesized and their recognition behavior with anionic guests has been studied. In DMSO solutions, sensors 1 and 2 show colorimetric responses for F⁻, H₂PO⁻₄ and AcO⁻, while in DMSO/H₂O (9:1, V/V) solutions, sensor 1 shows single selectivity for AcO⁻. ¹H NMR titration confirms that the tripodal sensors could bind anions through the collaboration of three hydrazone groups and anions residing in the central cavity of the sensors.     

芳酰基硫脲受体的合成及对阴离子识别研究

设计合成了3种芳酰基硫脲受体分子. 利用紫外-可见吸收光谱考察了其与F^－, Cl^－, Br^－, AcO^－, HSO₄^－, H₂PO₄^－等阴离子的作用. 结果表明该类受体分子与阴离子形成氢键配合物. 加入F^－, AcO^－时, 溶液立刻由无色变为黄色, 而加入其它阴离子则无变化, 从而实现对这两种阴离子的裸眼识别. 结果表明受体分子与阴离子间形成1∶1型的配合物. ¹H NMR滴定及质子溶剂效应为受体分子与阴离子间的氢键作用本质提供了直接依据.     

Determination Limit of Fluorescence Turn‐On Probes for the Acetate Anion

Three fluorescent turn‐on probes containing 3,6‐dichloro‐9H‐carbazole as carbazyl part have been designed and synthesized. Among studied anions F^?, AcO^?, H₂PO , Cl^?, Br^? and I^?, AcO^? showed the strongest binding ability with all probes. The strong basic anions, such as AcO^?, H₂PO , and F^?, induced a significant red‐shift in absorption and a concomitant increase in fluorescent emission of the probes caused by photoinduced electron transfer (PET). The determination limit of probe 3 (Scheme 1) toward AcO^? is 3.0×10^?7 M . ¹H‐NMR Titration experiments shed light on the nature of the interaction between the probes and the anions. Theoretical investigation further illustrated the possible binding mode in these host? guest interactions and the roles of molecular frontier orbitals in molecular interplay.     

Synthesis of Novel Anionic Receptors with （Thio）urea and Amide Binding Sites and the Recognition Properties for Anions

IntroductionSincemoreandmoreanionsplayanimportantroleinbiologicalandchemicalprocesses ,thedesignandsynthe sisofreceptorsforon lineandrealtimedetectionofbio logicallyimportantanions ,andforenvironmentalmonitor ingofharmfulanionpollutantshaveattractedparticularat tentioninsupramolecularchemistry .1Thebasicstrategyfortheconstructionofanion bindingreceptorsistoexploitthereceptorsthathaveelectrostatic ,2 hydrogenbonding ,3orLewisacidiccentralinteraction .4 Amongavarietyofnon covalentinteractions ,h…     

Synthesis,Physical Properties,and Anion Recognition of Two Novel Larger Azaacenes: Benzannelated Hexazaheptacene and Benzannelated N,N′‐Dihydrohexazaheptacene

Two novel larger azaacenes with six or ten N atoms in their backbones, benzannelated 9,11,13,22,24,26‐hexazatetrabenzo[a,c,l,n]heptacene ( HATBH , 1 ) and benzannelated 9,26‐dihydro‐9,11,13,22,24,26‐hexaza‐tetrapyrido[3,2‐a: 2′,3′‐c: 3′′,2′′‐l: 2′′′,3′′′‐n]heptacene ( DHATPH, 2 ), have been successfully synthesized in two steps. The theoretical band gaps estimated through DFT calculations for HATBH ( 1 ) and DHATPH ( 2 ) are 1.949 eV and 2.278 eV, which are close to the experimentally obtained optical band gaps (2.14 eV and 2.39 eV). Interestingly, HATBH ( 1 ) can act as efficient anion sensor for F^? and H₂PO₄^?, while DHATPH ( 2 ) selectively responds to F^? among the ten different anions used (F^?, Cl^?, Br^?, I^?, PF₆^?, HSO₄^?, NO₃^?, BF₄^?, AcO^?, and H₂PO₄^?). Our synthetic strategy could offer a promising and easy way to obtain even larger azaacenes.     

Synthesis of Indeno[2′,1′:5,6]pyrido[2,3‐d]pyrimidine Derivatives and Their Recognition Properties as New Type Anion Receptors

A new type anion receptors containing indeno[2′,1′:5,6]pyrido[2,3‐d]pyrimidine have been synthesized via three‐component reaction of aldehyde, 6‐aminopyrimidine‐2,4‐dione, and 1,3‐indanedione in aqueous media. The binding properties of the receptors with anions such as F^?, Cl^?, Br^?, AcO^?, HSO₄^?, and H₂PO₄^? have been investigated by UV–vis spectroscopy methods. The results have shown that receptors have good selectivity to F^? and AcO^?, and a 1:1 stoichiometry complex has been formed between compounds and anions.     

Synthesis of Schiff Base Bearing Phenolic Hydroxy Group and Its Anion Recognition

A new anion receptor bearing phenolic hydroxy group based on 3,5-ditertbutylsalicylaldehyde-p-nitrophenylhydrazone (1) was designed and synthesized. Upon addition of AcO^- and F^-, the receptor exhibited visible color changes from deep yellow to purple. However, no obvious color changes were observed on addition of the other anions tested (H₂PO₄^-, Cl^-, Br^-, I^-). The binding properties of the receptor with anions such as AcO^- and F^- were investigated by UV-Vis and fluorescent titrations. The result indicated that the receptor 1 had a higher affinity to AcO^- and F^- and a 1:1 host-guest complex was formed through H-bond interactions between 1 and anions.     

A Benzodithiophene‐Based Fluorescence Probe for Rapid Detection of Fluoride Ion

A novel and simple fluorescence probe was synthesized from benzo[1,2‐b:4,5‐b′]dithiophene (BDT) and trimethylsilylethyne via Sonogashira reaction, and showed highly selective and sensitive fluorescence decreasing response towards F^?. The probe molecule turned to a weakly fluorescent terminal alkyne moiety because its trimethylsilyl (TMS) group was cleaved by fluoride, which was proved by ¹H NMR titration. Whereas no distinct fluorescent changes were observed with the addition of other anions, such as Cl^?, Br^?, I^?, AcO^? and H₂PO₄^?. Upon the addition of F^?, the maximum fluorescence emission wavelength shifted from 460 nm to 450 nm with a decrease of fluorescence intensity by 40% within 20 s. Moreover, the detection limit towards F^? was calculated to be as low as 73.5 nmol/L.     

Efficient fluoride-selective receptor: experiment and theory

A novel artificial receptor, (3′-nitrobenzo)[2,3-d]-(3′′-nitrobenzo)[9,10-d]-1,4,8,11-tetraazacyclotetradecane-5,7,12,14-tetraone, has been synthesized and shows high selective and recognitive ability for F^- among F⁻, Cl⁻, Br⁻, AcO⁻, H₂PO₄⁻ by UV-vis and ¹H NMR titration experiments. Theoretical investigations suggest that the fluoride selectivity among various anions comes from the fact that the fluoride approaches much closer to the amide protons than other anions located above the cavity. The interaction energies support the large binding ability difference between F⁻ and Cl⁻/Br⁻/AcO⁻/H₂PO₄⁻.     

基于酰胺的荧光双冠醚阴离子受体的合成和识别性能研究

合成了一种带有荧光基团蒽的酰胺型双冠醚阴离子受体3. 用荧光光谱、紫外-可见吸收光谱及核磁共振氢谱研究了其与F^－, Cl^－, Br^－, I^－, H₂PO₄^－, AcO^－离子的相互作用, 结果表明3只对F^－具有很好的选择性识别能力, 并形成配合比为1∶2的络合物, 通过荧光发射强度计算出主体3与F^－间的相互作用时的结合常数.     

Colorimetric naked‐eye recognizable anion sensors synthesized via RAFT polymerization

A polymeric sensor (PTH) containing naphthalimide signal moiety and thiourea recognition moiety for the detection of anions was synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization, which can guarantee controllable molecular weight, narrow molecular weight distribution, and precise polymer structure. Both PTH and its corresponding monomer (TH) showed naked‐eye recognizable yellow‐to‐orange changes upon addition of fluoride (F^?), acetate (AcO^?), and dihydrogen phosphate (H₂PO) of low concentration. However, only F^? can result in orange‐to‐purple change when the aforementioned anions were added at high concentrations, which was attributed to the deprotonation of the thiourea N? H groups and the mechanism was supported by the UV‐Vis absorption spectra and ¹H NMR titration. The effect of these anions on thin PTH films was also investigated, and the addition of F^? led to obvious spectra change. It was found that other halide anions (Cl^?, Br^?, and I^?) could hardly induce any variation of absorption spectra. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1551–1556, 2010     

Epoxy-based oligomeric probe bearing naphthalene units for selective turn-OFF fluorescent sensing of fluoride anion

A simple epoxy-based oligomer 1 bearing naphthalene unit at the chain-ends is reported to be highly selective ON–OFF type fluorescent probe for fluoride anion. The titled oligomer displayed fluorescence quenching upon addition of F^?, resulting in selective detection of fluoride anion over other anions, such as AcO^?, Cl^?, Br^?, I^?, HSO₄^?, NO₃^? and H₂PO₄^? in CH₃CN. Fluorescence experiments suggest the significant influence of the oligomer chain on the sensitivity and selectivity of 1 towards fluoride anion.     

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.     

A novel neutral receptor for selective recognition of H2PO 4 −

A new urea-based receptor was designed to selectively recognize H₂PO₄⁻ among other anions (such as F^-, Cl^-, Br^-, I^-, OH^-, AcO^-) in organic solvent (DMSO) through intermolecular hydrogen bonding. Addition of anions to the receptor caused changes in UV–vis spectrum which provided the first indication of its anion binding ability. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis of a Phenylhydrazone‐based Colorimetric Anion Sensor with Complementary IMP/INH Logic Functions

A dinitrophenyl hydrazone colorimetric anion sensor (receptor 1 ) was synthesized and its recognition properties towards various anions were investigated by naked eye observation and spectroscopic methods, namely UV‐vis and ¹H NMR titrations in DMSO. The addition of AcO^?, F^? and H₂PO₄^? to receptor 1 resulted in marked red shift of the charge‐transfer absorbance band (Δλ=91 nm, 407 nm to 498 nm) concomitant with a 'naked‐eye' detectable colour change from yellow to pink. However, both the colour and spectral changes were reversible by the addition of cations (M^II) of 3d^5‐10 as well as Cd^II, Hg^II, Mg^II and Ca^II. Subsequently, complementary IMP/INH logic functions based on colour and spectral switching (ON/OFF) were affirmed. The sensor can, thus be utilized as a colorimetric molecular switch modulated by F^?/M^II.     

Synthesis,Bioactivity, and the Anion‐Binding Property of 2‐Sulfydryl‐1,3,4‐thiodiazole Derivatives

Two new compounds ( 1 and 2 ) containing 2‐sulfydryl‐1,3,4‐thiodiazole have been synthesized and optimized. They both showed wide antibacterial activity for colon bacillus, Staphylococcus aureus, S. albus, dysentery bacillus and inferior activity for Bacillus subtilis. In addition, their binding properties were evaluated for biologically important anions (F^–, Cl^–, Br^–, I^–, AcO^–, and H₂PO₄^–) by theoretical investigation, UV–vis, fluorescence, and ¹H NMR titration experiments, and they displayed strong binding ability for H₂PO₄^– without the interference of other anions tested. Especially the binding ability of compound 2 containing anthracene with H₂PO₄^– was 1000 times stronger than that of compound 1 containing nitrobenzene. Two compounds based on 2‐sulfydryl‐1,3,4‐thiodiazole have both properties of anion recognition and antibacterial activity.     

A new colorimetric and fluorescent chemosensor based on thiacalix[4]arene for fluoride ions

A new thiacalix[4]arene based fluorescent chemosensor thiacalix[4]arene-N-(quinolin-8-yl)acetamide (TCAN8QA) has been synthesized. TCAN8QA has been found to exhibit highly selective behavior for F⁻ ions among all other anions, that is, Cl⁻, Br⁻, I⁻, PO₄⁻³, OH⁻, H₂PO₄⁻, and CH₃COO⁻ in the absorption spectra as well as in the emission spectra. Red shift and quenching in emission spectra constituting the signature for fluoride detection are due to photoinduced charge transfer (PCT) which can be attributed to deprotonation of acidic NH proton in the presence of fluoride ions.