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Abstract: Two novel tripodal ligands, N,N′,N″-tri-(3′-phenylpropionic acid-2′-yl-)-1,3,5-triaminomethylbenzene (L1), N,N′,N″-tri-(4′-methylvaleric acid-2′-yl-)-1,3,5-triaminomethylbenzene (L2) have been synthesized. The hydrolytic kinetics of p-nitrophenyl phosphate (NPP) catalyzed by complexes of L1, and L2 with La(III) and Gd(III) have been studied in aqueous solution at 298K, I =0.10moldm−3 KNO3 at pH 6.7–8.2, respectively. In the study it is found that the catalytic effect of GdL2 was the best in the four complexes for hydrolysis of HPNP. Its , k LnL and pK a are 0.0198mol−1 dm3 s−1, 0.0000187mol−1 dm3 s−1 and 7.76, respectively. This paper expounds the result from the structure of the ligands and the properties of the metal ions, and deduces the catalysis mechanism. [Copyright &y& Elsevier]

A novel selective and sensitive colorimetric receptor 1 (1, 10-phenanthroline-2, 9-dialdehyde bis-(-p-nitrophenylureasemicarbo-hydrazone)) based on urea showing distinctive color fading phenomenon towards H2PO4− ion was reported. Fancifully, the recognition process of receptor 1 to H2PO4− was not interfered by the existence of others anions. We have probed the binding mechanism of 1-H2PO4− that H2PO4− ion induced competitive hydrogen binding process via intramolecular hydrogen-bond by UV-vis, fluorescence, 1H NMR titrations and ESI-MS experiments. [ABSTRACT FROM AUTHOR]

Abstract: A novel phosphonium derivative of anthracene was rationally designed and synthesized by the reaction of 9,10-dibromomethylanthracene with triphenylphosphine. This receptor showed a distinct UV–vis and fluorescence change when treated with acetate ions in aqueous solutions, as a result of a combined effect of electrostatic force and hydrogen bonding interactions. In addition, 1H NMR and 31P NMR titrations were carried out to explore the nature of interaction between receptor 1 and acetate. Finally, we discussed and analyzed the proposed mode of the host–guest bonding in solution. [Copyright &y& Elsevier]

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. [ABSTRACT FROM AUTHOR]

A simple, novel anion receptor based on 4-hydroxy-3-(N-phenyl-thiourea-N′-nitrilo-methylidynyl)-azobenzene with hybrid –OH and thiourea binding sites was synthesized and characterized. Anion binding character was determined using visual inspection, UV–vis, fluorescence and 1H NMR analyses. The addition of F−, AcO− and H2PO4 − resulted in a marked red shift of the charge-transfer absorbance band (Δλ =140nm, from 340nm to 480nm) accompanied by a color change from light yellow to orange. [Copyright &y& Elsevier]

Abstract: A simple colorimetric and ratiometric fluorescent anion sensor 1, 3,6-dichloro-1,8-dinitrocarbazole, was rationally designed and synthesized on basis of the mechanism of intramolecular charge transfer (ICT). In DMSO solutions of 1, the presence of AcO−, F− and H2PO4 − gave birth to the formation of a 2:1 host-to-guest complex, which was synchronously accompanied by a ‘naked-eye’ color change from light yellow to purple, a red-shift of the absorption spectrum and a blue-shift of the emission spectrum. [Copyright &y& Elsevier]

A carbazole-based neutral anion receptor 3 has been designed and synthesized. Anion binding studies carried out using 1H NMR and UV-visible reveal that this compound showed good selectivity for the iodide ion over other anions. The high selectivity for iodide ion among the anions is attributed mainly to the complementarity of the geometries between the receptor 3 and iodide ion. [ABSTRACT FROM AUTHOR]

A 3D supramolecular complex [Co(III)(Phen)2Cl2][DNQ]Cl·H2O (DNQ = 6,7-dinitroquinoxaline-2,3-dione) has been synthesized and determined by single-crystal X-ray analysis. Anion binding studies carried out using 1H NMR and UV-visible revealed that a genuine hydrogen bond interaction between anion receptor 2 and Cl- can be detected, but fluoride is deprotonating the anion receptor 2. X-ray analysis results show that it is not possible for the two amide nitrogen atoms of anion receptor to form hydrogen bonds to a chloride ion in the presence of small aliquots of water. [ABSTRACT FROM AUTHOR]

Abstract: Two multidentate ligands: N,N′-di-(propionic acid-2′-yl-)-2,9-di-aminomethylphenanthroline (L1) and N,N′-di-(3′-methylbutyric acid-2′-yl-)-2,9-di-aminomethylphenanthroline (L2) were synthesized. The hydrolytic kinetics of 2-hydroxypropyl-p-nitrophenyl phosphate (HPNP) catalyzed by complexes of L1 and L2 with La(III), Gd(III) have been studied. Both LnL and LnLH−1 have been examined as catalysis for the hydrolysis of HPNP in aqueous solution at 298K, I =0.10moldm−3 KNO3 at pH range 7.4–9.1, respectively. Kinetic studies show that both LnL and LnLH−1 have activity, but LnLH−1 is more active than LnL in the hydrolysis reaction of HPNP. The second-order rate constants of hydrolysis of HPNP are , k GdL1 =0.000037mol−1 dm3 s−1 for GdL1H−1 and GdL1, respectively. New mechanism was proposed for the hydrolysis reaction of HPNP catalyzed by LnL and LnLH−1. [Copyright &y& Elsevier]

The protonation constants and the stability constants for the formation of copper (II) complex of the ligand [1,4,7] Triazecan-9-ol (L) were presented. Antitumor activity of CuL complex was reported. Preliminary pharmacological tests showed that it had antitumor activity against HXO-RB44 and BEL-7402 cell lines in vitro. Nuclei of [CuL]-stimulated BEL-7402 cells clearly exhibited condensation and break down into chromatin clumps typical of apoptosis. Also it exhibited perturbation effects to BEL-7402 cell lines cycle and further studies showed that it could cleave supercoiled DNA (pBR 322) to nicked and linear DNA. [Copyright &y& Elsevier]

Three new selective anion receptors containing the (thio)urea binding sites were developed, Indole-3-formaldehyde phenyl-semithiocarbazone, Indole-3-formaldehyde nitrophenyl-semithiocarbazone, and Indole-3-formaldehyde nitrophenyl-semicarbazone, nominated as receptors 1, 2 and 3, respectively. Receptor 1 shows high selective recognition for F only, while both receptor 2 and receptor 3 containing a p-nitro group show high selective recognition for AcO. The high selective recognition of these receptors to anions is further investigated by X-ray crystallography diffraction, UV-vis, fluorescence analyses and H NMR. Furthermore, receptor 2 changes from yellow to orange, and receptor 3 darkens when acetate is added, providing a way of detection by 'naked-eye'. [ABSTRACT FROM AUTHOR]

Abstract: Two novel highly sensitive colorimetric acetate anion receptors: 4-phenylazo-2-hydroxy-benzaldehyde 4-nitrophenylhydrazone (1) and 4-phenylazo-2-hydroxy-benzaldehyde 2,4-dinitrophenylhydrazone (2) based on azo derivative have been designed and synthesized. UV–vis experiments show that receptor 1 and receptor 2 can selectively recognize acetate in DMSO and even in 9/1 DMSO/H2O (v/v) mixtures. Meanwhile the color changes induced by anions can provide a way of detection by ‘naked-eye’. The further insights to the nature of interactions between receptor 1, 2 and AcO− have been investigated by 1H NMR titration experiments. [Copyright &y& Elsevier]

Abstract: A novel artificial anion receptor based on phenylhydrazone structure was designed, synthesized and characterized. The binding behavior of the receptor to various anions was investigated by UV–vis fluorescence analyses. In addition, 1H NMR experiments were carried out to explore the nature of interaction between receptor 1 and acetate. The processes of sensing can literally be seen through the ‘naked-eye’ for the sharp color changes from yellow to purple. [Copyright &y& Elsevier]

Abstract: A novel colorimetric anion-chemosensor based on 1,10-phenanthroline-2,9-dicarbonyl-p-nitro-phenylhydrazine has been synthesized. Among the different anions tested, it shows the best selectivity towards AcO−. The addition of acetate causes the color to change from yellow to red, which could be detected with naked eyes. The binding ability of chemosensor 1 with anions has been investigated through UV–vis spectral titrations. In addition, 1H NMR experiment was carried out to explore the nature of interaction between chemosensor 1 and acetate. [Copyright &y& Elsevier]

novel artificial anion chemosensor 1 based on 2, 2′-di (4-nitrophenylurea-β- N-yl) -1, 1′-binaphthyl is designed and synthesized for sensing anions including halide ions and oxoanions. The fluorescent emission of the binaphthyl of receptor 1, forming the hydrogen bonding with anions as the sensing mechanism, is monitored in DMSO for detecting anions. In brief, while most of the anion chemosensors are switch-off fluorescent chemosensor, or non-fluorescent sensor, receptor 1 exhibits obviously the switch-on emission during the complexation with HPO. [ABSTRACT FROM AUTHOR]

Abstract: A novel sensor for acetate containing thiourea and hydrazone structure has been synthesized. The anion recognition via hydrogen-bonding interactions could be monitored by anion complexation, which induced changes in UV–vis and fluorescence spectra. In particular, the recognition process could be easily detected by the ‘naked-eye’. Further insights to the nature of interactions between receptor 1 and AcO− were obtained by 1H NMR titration experiments. [Copyright &y& Elsevier]

Abstract: A colorimetric sensor 1,N,N′-di-(2-hydroxy-5-(phenldiazenyl)benzaldehyde)-1,3-diiminothiourea for acetate in DMSO and 9/1 DMSO/H2O (v/v) mixtures was designed and synthesized. The binding ability evaluated by UV–vis experiment reveals that sensor 1 can selectively recognize acetate. In addition, the color changes induced by anions can provide a way of detection by ‘naked-eye’. The further insights to the nature of interactions between the sensor 1 and AcO− were investigated by 1H NMR titration experiments in 9/1 DMSO-d 6 /H2O (v/v). [Copyright &y& Elsevier]

Abstract: A new highly sensitive colorimetric receptor 1 for fluoride based on anthracene-9,10-dicarbaldehyde bis-p-nitrophenylhydrazone was designed, synthesized and characterized. Experiments showed that the receptor 1 can selectively recognize the fluoride in DMSO and even in 95/5 DMSO/H2O (v/v) mixtures. The ability of recognition and the bond between receptor 1 and anions were determined using visual inspection, UV–vis and fluorescence analyses. In addition, 1H NMR experiments were carried out to explore the nature of interaction between receptor 1 and fluoride. Finally, analytical application and detection of fluoride in toothpaste have been studied. [Copyright &y& Elsevier]

Abstract: 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 1H 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 280nm. [Copyright &y& Elsevier]

Abstract: 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 results in a notable change in the visible region of spectrum (an approximately 90nm 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− > ≫Cl−, Br−, I−. The nature of the color change of 1 induced by AcO− was due to the intramolecular charge transfer (ICT) which was confirmed by X-ray crystal structure and 1H NMR titration spectra. [Copyright &y& Elsevier]

Abstract: A novel positive homotropic allosteric system 1 based on 3-methylpyrozole-5-one-4-one-2′,4′-dinitrophenylhydrazone was designed, synthesized and characterized. Colorimetric and fluorescent sensing of anions was achieved in physiological condition (pH 7.4), resulting from the positive homotropic allosterism of 1 induced by anions tested. In particular, the compound 1 exhibited a two-step response to the strong basic anions such as F−. In the first step, the hydrazone form of 1 interacted with anions through hydrogen bonding with an obvious color change from yellow to orange upon addition of 0.3equiv. of anions. In the second step, with further addition of anions, the hydrazone form of 1 was shifted to the azophenol form, whose anion binding was accompanied with an orange-to-purple color change. In addition, the receptor 1 exhibited a fluorescent enhancement response to anions exploiting two possible signaling transduction mechanisms: (1) inhibition of photoinduced electronic transfer (PET) and (2) binding-induced rigidity of the host molecule. [Copyright &y& Elsevier]

Abstract: A new and simple salicylaldehyde-based sensor 1 designed for fluoride sensing has been investigated in DMSO and even in the 9/1 DMSO/H2O (v/v) mixtures. The affinity constants of receptor 1 for anionic species in the 9/1 DMSO/H2O (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 25equiv. anions to 1 in the 9/1 DMSO/H2O solution. The further insights to the nature of interactions between the sensor 1 and F− were investigated by 1H NMR titration experiments in 9/1 DMSO-d 6/H2O (v/v). In addition, the proposed binding mode between 1 and F− was suggested. [Copyright &y& Elsevier]

Abstract: 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 1 can selectively recognize fluoride. In particular, addition of F− to the DMSO solution of 1 resulted in an enhancement in fluorescence intensity at 338 and 352nm, which can provide a way of ‘naked-eye’ detection for fluorides. The spectral change of 1 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 1H NMR experiments. [Copyright &y& Elsevier]

Abstract: A simple colorimetric and fluorescent anion chemosensor based on amide moieties, 6-nitro-1,4-dihydroquinoxaline-2,3-dione has been designed, synthesized and characterized by 1H NMR, ESI-MS and elemental analyses. The strong basic anions such as F− and AcO− resulted in significant decrease in fluorescent emission intensity of the compound 1, accompanied synchronously with a dramatic color change from colorless to deep yellow in organic medium. 1H NMR titration experiments shed light on the nature of the interactions between 1 and the anions. [Copyright &y& Elsevier]

Abstract: Tris–hydrazone (1) functioned as a colorimetric chemosensor for a variety of anions such as F−, AcO− and H2PO4 −. The anion binding could be easily detected by naked-eye according to color changes. The high binding ability of the receptor 1 to anions was further investigated by UV–vis absorption spectroscopy in DMSO. The results of job plot of the receptor 1 with different anions demonstrated that the stoichiometry of the complex between 1 and F− was 1:1 (1:anion) and the stoichiometry of the other complexes studied was 1:3 (1:anion). [Copyright &y& Elsevier]

The anion sensing ability of compound 1 based on a novel 2,4-dinitrophenylhydrazone derivative was studied through 'naked-eye' experiment, UV-Vis spectral titration, and 1H NMR titration. Sensor 1 was synthesized through a simple method with high yield. The solution of host 1 turned deep purple from light purple in the presence of the strong basic anions and turned yellow upon addition of the weak basic anions, respectively. The results could be explained on the basis of transfer of the tautomeric equilibrium of sensor 1 induced by anions with different basicity. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: A novel and simple fluorescent receptor bearing thiourea moiety as recognition site was described. The recognition behavior of the receptor toward different anions was investigated in DMSO/H2O (95:5 v/v) and dry DMSO through two various channels: the colorless-yellow color change and a remarkable enhancement of the fluorescence. And the enhancement of the fluorescence was attributed to an anion-induced increase of the rigidity of the host molecule. [Copyright &y& Elsevier]

Abstract: Five multi-dentate ligands: N,N′-di-(1,10-phenanthroline-2-methylene)-ethylenediamine (L1), N,N′-di-(1,10-phenanthroline-2-methylene)-1,3-propanediamine (L2), 1,7-di- (1,10-phenanthroline-2-methylene)-1,4,7-triazaheptane (L3), 1,10-di-(1,10-phenanthroline-2-methylene)-1,4,7,10-tetraazatridecane (L4), 1,13-di-(1,10-phenanthroline-2-methylene)-1,4,7,10,13-pentaazatridecane (L5) have been synthesized and characterized. The hydrolytic kinetics catalyzed by dinuclear complexes of Zn(II) with L1–L5 have been studied in aqueous solution at 298.2±0.1K, I =0.10moldm−3 KNO3 at physiological condition (pH 7.0–8.4), respectively. In this study it is found that the catalytic effect of Zn2L3 was the best one among the five dinuclear complexes for the hydrolysis of 2-hydroxy-propyl-p-nitrophenyl phosphate (HPNP). Its , and pK a are 0.0480mol−1 dm3 s−1, 0.000043mol−1 dm3 s−1 and 8.87, respectively. This paper expounds the result from the structure of the ligands and the properties of the metal ions, and deduces the catalysis mechanism. [Copyright &y& Elsevier]

Abstract: A novel receptor based on phenylhydrazone derivative was developed and applied to the binding anion, showing a common preference for acetate (AcO−) ion, and the preference was related to structure matching between the host and the guest. The receptor exhibited a dramatic color change upon the addition of acetate ions so that we could finish anion recognition by naked eye without resorting to any spectroscopic instruments. The evaluation of the receptor interaction with anions was performed by UV–vis titration experiments with a variety of structurally different anions in DMSO, and the anion binding pattern of the chemosensor was hydrogen bond interactions. [Copyright &y& Elsevier]

Abstract: A new and simple phenylhydrazone-based sensor 1 for acetate has been investigated in DMSO and even in the 95:5 DMSO/H2O (v/v) mixtures. Binding of anions such as AcO−, F− and H2PO4 − results in a noteworthy change in the visible region of spectrum (approximately 100nm red shift), which can be detected by the ‘naked-eye’. The further insights to the nature of interactions between the sensor 1 and AcO− were investigated by 1H NMR titration experiments in DMSO-d 6. In particular, analytical application and detection of acetate ion have been also studied in the aqueous. [Copyright &y& Elsevier]

Abstract: An efficient AcO− sensor L which contains 1,10-phenanthroline-based and nitrophenylhydrazine-based groups, and its water-soluble Ru(II) complex were synthesized, characterized and studied in this Letter. Via UV–vis experiments and 1H NMR titration in DMSO solution, it was found that there were potential hydrogen bonds between the NO− after the deprotanation of two –NH during the reaction of L or its Ru complex with anions. Furthermore, an easy-to-prepare test paper was developed to detect AcO− at 10mg/L in pure aqueous solution. [Copyright &y& Elsevier]

Abstract: Two novel tripodal ligands, N,N′,N″-tri-(3′-phenylpropionic acid-2′-yl)-1,3,5-tri-aminomethylbenzene (L1), N,N′,N″-tri-(4′-methylvaleric acid-2′-yl)-1,3,5-triamino-methylbenzene (L2) have been synthesized. The hydrolytic kinetics of 2-hydroxy-propyl-p-nitrophenyl phosphate (HPNP) catalyzed by complexes of L1, and L2 with La(III) and Gd(III) have been studied in aqueous solution at 298K, I =0.10moldm−3 KNO3 at pH 6.7–8.2, respectively. GdL2 has the best catalytic effect in the four complexes for hydrolysis of HPNP. Its k LnLH−1, k LnL and pK a are 0.0927mol−1 dm3 s−1, 0.000101mol−1 dm3 s−1 and 7.73, respectively. Due to smaller radius of Gd(III) compared with that of La(III), its complexes have lower pK a and better catalytic ability compared with corresponding La(III) complexes. This paper expounds the result from the structure of the ligands and the properties of the metal ions, and deduces the catalysis mechanism. [Copyright &y& Elsevier]

Abstract: Two novel ligands 2-(1′-phenyl-2′-carboxyl-3′-aza-n-butyl)-1,10-phenanthroline (L1) and 2-(1′-p-phenol-2′-carboxyl-3′-aza-butyl)-1,10-phenanthroline (L2), and their La(III) complexes of La(III)L1, La(III)(L1)2, La(III)L2, and La(III)(L2)2, were synthesized and characterized by 1H NMR, elemental analysis, IR, thermal analysis and conductance measurement. All complexes have been assayed for anticancer activity in vitro against HL-60 (human leukocytoma) cells, PC-3MIE8 (human prostate carcinoma) cells, BGC-823 (human stomach carcinoma) cells, MDA-MB-435 (human galactophore carcinoma) cells, Bel-7402 (human liver carcinoma) cells, and HeLa (human cervix carcinoma) cells. Results showed that the two complexes La(III)L1 and La(III)(L1)2 exhibited good cytotoxic activity against different cell lines in general; and La(III)(L1)2 is more effective than cisplatin against all six cell lines. DNA-binding studies indicated that, besides the intercalation, the complexes bind to DNA by the other interaction(s). [Copyright &y& Elsevier]

A benzimidazole-based anion receptor 1 has been designed and synthesized. The structure of 1 is confirmed through single crystal X-ray diffraction analysis. Anion-binding studies carried out using 1H NMR and UV-visible revealed that this compound exhibits selective recognition toward F− over other halide anions. The highest selectivity for F− among the halides is attributed mainly to the strongest hydrogen-bond interaction of the receptor with F−; in addition, the higher match in geometry between the receptor and F− also plays a role in the selective recognition of the receptor for F−. Receptor 1 (1 × 10−5 M) shows dramatic color change from light-yellow to red in the presence of tetrabutylammonium fluoride (TBAF) (1 × 10−5 M). Moreover, F−-induced color changes remain the same even in the presence of a large excess of Cl−, Br−, I−. Copyright © 2006 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The chelate ligand 2,9-di(6′-α-phenol-n-2′,5′-diazahexyl)-1,10-phenanthroline (L) was synthesized and fully characterized. This ligand formed six protonated species in the solution. The bindings of the ligand to the nucleotide anions ATP, ADP and AMP were described in detail, with equilibrium constants given for each species formed. The strength of binding increased with the number of protons, corresponding to an increase in the number of hydrogen bonds and an increase in the coulombic attractive forces. At the same time, the coordination properties of the ternary complexes formed from the chelate ligand above, M (M=Zn2+, Cd2+) and adenosine-5′-triphosphate (ATP) were studied. The metal complexes of the chelate recognize the nucleotides via multiple interactions similar to those occurring in the center of enzymes. The hydrolysis of ATP was studied with the mononuclear and trinuclear chelate complexes. [Copyright &y& Elsevier]

The stability constants for the formation of nickle(II) and cobalt(II) complexes of the ligand [1,4,7]triazecan-9-ol (L) were presented. Antitumor activity of two complexes was reported. Nuclei of [NiL]-stimulated BEL-7402 cells clearly exhibited condensation and break down into chromatin clumps typical of apoptosis. Also it exhibited perturbation effects to cell cycle, and optimal induction of apoptosis was found by Flow-Cytometric analysis. But CoL complex did not exhibit introduction effects to BEL-7402 cells apoptosis; and could not perturb cell cycle. NiL and CuL complexes could cleave supercoiled DNA (pBR 322 DNA) to nicked and linear DNA, and DNA of cells treated with NiL or CuL complex was obviously damaged; while CoL complex only could cleave supercoiled DNA (pBR 322 DNA) to nicked DNA, and DNA of cells treated with CoL complex had no significant difference with control. [Copyright &y& Elsevier]

The phenanthroline (Phen)-based polyaza ligands can efficiently recognize nucleotides and significantly enhance the rate of ATP hydrolysis under the regulation of metal ions, which act as “messenger” between the substrates and the receptors. The water molecule (or –OH) participates in the catalytic hydrolysis of ATP in different steps with different functions. [Copyright &y& Elsevier]