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Due to the prime importance of anions in various domains involving biology or environment, the design of molecular synthetic receptors that have the ability to selectively bind and sense anionic guests via a macroscopic physical response... more
Due to the prime importance of anions in various domains involving biology or environment, the design of molecular synthetic receptors that have the ability to selectively bind and sense anionic guests via a macroscopic physical response is an area of intense activity in ...
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ABSTRACT The complexation of copper(II)(from the perchlorate) by two tripodal ligands H2L bearing one pyridine and two phenolic arms has been studied in co-ordinating solvents. One of the ligands bears a MeS group at the para position of... more
ABSTRACT The complexation of copper(II)(from the perchlorate) by two tripodal ligands H2L bearing one pyridine and two phenolic arms has been studied in co-ordinating solvents. One of the ligands bears a MeS group at the para position of one of the phenolic moieties. In the presence of triethylamine, only brown dimeric neutral complexes [(CuL)2] have been obtained. In the absence of base, green [Cu(HL)]+ complexes were identified, in which one of the phenolic ligands remains protonated. The brown and the green complexes are reversibly interconverted upon addition of acid or base. Some evidence is given supporting the hypothesis of protonation of the axial tyrosine ligand in the form of galactose oxidase which has been isolated with an exogenous ligand bound to Cu. Electrochemical studies have been performed for the free pro-ligands and for the copper complexes.
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Copper and Active site
ABSTRACT Arsenic species can be removed from aqueous solutions using the liquid-phase polymer-based retention, LPR, technique. The LPR technique removes ionic species by functional groups of water-soluble polyelectrolytes (WSP) and then... more
ABSTRACT Arsenic species can be removed from aqueous solutions using the liquid-phase polymer-based retention, LPR, technique. The LPR technique removes ionic species by functional groups of water-soluble polyelectrolytes (WSP) and then using a ultrafiltration membrane that does not let them pass through the membrane, thus separating them from the solution. The ability of WSP with groups (R)4N+X− to remove arsenate ions using LPR was studied. The interaction and arsenate anion retention capacity depended on: pH, the quaternary ammonium group's counter ion, and the ratio polymer: As(V), using different concentrations of As(V). Water-soluble polychelates were also used for one-step retention of As(III) in solution. The complex of poly(acrylic acid)-Sn, 10 and 20 wt-% of metal gave a high retention of As(III) species at pH 8, although the molar ratio polychelate: As(III) was 400:1. The enrichment method was used to determine the maximum retention capacity (C) for arsenate anions in aqueous solutions at pH 8. In similar conditions, the values of C were 142 mg g−1 for P(ClAETA) and 75 mg g−1 for P(SAETA). The combined treatment of arsenic aqueous solutions by electrocatalytic oxidation (EO) to convert the species of As(III) to As(V) with the LPR technique quantitatively removed arsenic.
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ABSTRACT A new electroactive ligand L built on the Taci (1,3,5-triamino-1,3,5-trideoxy- cis- inositol) platform and bearing three chemically equivalent ferrocene units was prepared and characterized. Electrochemical investigations... more
ABSTRACT A new electroactive ligand L built on the Taci (1,3,5-triamino-1,3,5-trideoxy- cis- inositol) platform and bearing three chemically equivalent ferrocene units was prepared and characterized. Electrochemical investigations indicate that electrostatic communication occurs between the three ferrocene groups in L, this electrochemical communication being disrupted in the presence of protons or nucleophilic reagents. Upon addition of metal cations, the electroactivity of L is strongly modified and a remarkable electrochemical signature of the coordination mode adopted by the corresponding complexes is obtained.
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Arsenic is one of the most hazardous pollutants, and is present in water, mainly, as As(V) and As(III), and in its inorganic hydrolysis species. Great efforts have been made to develop effective removal techniques. One al-ternative is the... more
Arsenic is one of the most hazardous pollutants, and is present in water, mainly, as As(V) and As(III), and in its inorganic hydrolysis species. Great efforts have been made to develop effective removal techniques. One al-ternative is the use of water-soluble polymers contain-ing ...
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ABSTRACT
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Mononuclear complexes of an unsymmetrical bicompartmental ligand containing an iron ion that can occupy either the 'soft nitrogen box'or the 'hard oxygen box'have been synthesized. When the ferric iron is... more
Mononuclear complexes of an unsymmetrical bicompartmental ligand containing an iron ion that can occupy either the 'soft nitrogen box'or the 'hard oxygen box'have been synthesized. When the ferric iron is electrochemically reduced or when the ferrous iron is ...
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... Commun., 2001, 2646 RSC Article ; (k) VA Nadtochenko, DV Khudyakov, EV Vorontsov, NM Loim, FE Gostev, DG Tovbin, AA Titov and OM Sarkisov ... 16, This is in full agreement with literature values obtained with ZnTPP in similar... more
... Commun., 2001, 2646 RSC Article ; (k) VA Nadtochenko, DV Khudyakov, EV Vorontsov, NM Loim, FE Gostev, DG Tovbin, AA Titov and OM Sarkisov ... 16, This is in full agreement with literature values obtained with ZnTPP in similar conditions: (a) M. Nappa and JS Valentine, J. Am ...
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New and CHEMICAL SCIENCES
(Ferrocenylmethyl)trimethylammonium cation: a very simple probe for the electro-chemical sensing of dihydrogen phosphate and ATP anionsElectronic supplementary information (ESI) available: cyclic voltammograms of 1 in the presence of increasing amounts of ATP2– or HSO4–. See http://www.rsc.org/su...more
... Anion binding plays a central role in chemical and biochemical processes and their recognition by artificial molecular hosts is an area of intense current interest.1 An application of anion receptor chemistry would be the qualitative... more
... Anion binding plays a central role in chemical and biochemical processes and their recognition by artificial molecular hosts is an area of intense current interest.1 An application of anion receptor chemistry would be the qualitative and quantitative sensing of selectively bound ...
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New and CHEMICAL SCIENCES
ABSTRACT The complexing properties of poly (3-(pyrrol-1-yl)propylmalonic acid) (poly1) and poly(N,N′-ethylenebis[N-[(3-(pyrrole-1-yl)propyl) carbamoyl) methyl]-glycine (poly2) coated electrodes (C|poly1 and C|poly2) towards Cu(II),... more
ABSTRACT The complexing properties of poly (3-(pyrrol-1-yl)propylmalonic acid) (poly1) and poly(N,N′-ethylenebis[N-[(3-(pyrrole-1-yl)propyl) carbamoyl) methyl]-glycine (poly2) coated electrodes (C|poly1 and C|poly2) towards Cu(II), Pb(II), Hg(II) and Cd(II) cations using the open circuit chemical preconcentration-anodic stripping technique were studied. Sorption process of metal cations onto complexing surfaces was readily investigated through the combination of a chemical pre-concentration-anodic stripping technique with a Langmuir isotherm model. The modified electrodes were used for the voltammetric determination of Cu(II), Pb(II), Hg(II) and Cd(II) ions, giving low detection limits for Cu(II) (5 × 10−9 mol L−1) and Pb(II) (5 × 10−10 mol L−1). The ability of the modified electrodes to analyze Cu(II) ions in natural sample has been demonstrated by the analysis of a tap water sample. The results of the preconcentration process under competitive conditions clearly shows that the selectivity of complexing molecular electrode materials can be subtly tuned upon playing on the accumulation time, polymer thickness and/or memory effect of the binding polymers, opening up new avenues towards evolutive and efficient smart sensing materials.
ABSTRACT Soluble coordination polymers and gels built from a polytopic ligand containing two terpyridine units linked by a azamacrocyclic group are presented. This system originally incorporates two different types of metal complexes in... more
ABSTRACT Soluble coordination polymers and gels built from a polytopic ligand containing two terpyridine units linked by a azamacrocyclic group are presented. This system originally incorporates two different types of metal complexes in the same polymer chain which induces remarkable electrochromic properties and a rare redox triggered reversible sol-gel transition.
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A nanometer scale redox active biomolecular architecture has been successfully synthesized through an efficient chemoselective oxime based coupling between ferrocenyl groups and a regioselectively addressable cyclodecapeptide. This... more
A nanometer scale redox active biomolecular architecture has been successfully synthesized through an efficient chemoselective oxime based coupling between ferrocenyl groups and a regioselectively addressable cyclodecapeptide. This molecular tool exhibits electronic, structural, and chemical properties driven by the biomimetic recognition activity of the polypeptide skeleton associated to the well-defined electrochemical activity of metallocenyl probes. Biomolecular materials obtained by confinement of the redox cyclopeptide in self-assembled monolayers on gold surfaces shows efficient through-bond electron transfer from the ferrocenes to the electrode surface via the peptidic backbone, as well as markedly improved sensing properties toward anionic species in organic electrolyte, as compared to those observed in homogeneous solution.
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Due to the prime importance of anions in various domains involving biology or environment, the design of molecular synthetic receptors that have the ability to selectively bind and sense anionic guests via a macroscopic physical response... more
Due to the prime importance of anions in various domains involving biology or environment, the design of molecular synthetic receptors that have the ability to selectively bind and sense anionic guests via a macroscopic physical response is an area of intense activity in ...
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The complexing ability of thin poly (3-pyrrol-1-ylpropyl) malonic acid films coated onto glassy carbon disc electrode surfaces was evaluated towards Pb (II) and Cu (II) ions, using the chemical preconcentration-anodic stripping method.... more
The complexing ability of thin poly (3-pyrrol-1-ylpropyl) malonic acid films coated onto glassy carbon disc electrode surfaces was evaluated towards Pb (II) and Cu (II) ions, using the chemical preconcentration-anodic stripping method. The affinity of these metal cations for ...
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... In non-coordinating solvents such as dichloromethane, only an EPR-silent dimeric complex was obtained (L2Cu2). The crystal structure of L2Cu2 revealed a butterfly design of the [Cu(μOR)2Cu] unit, which is not flattened and leads to... more
... In non-coordinating solvents such as dichloromethane, only an EPR-silent dimeric complex was obtained (L2Cu2). The crystal structure of L2Cu2 revealed a butterfly design of the [Cu(μOR)2Cu] unit, which is not flattened and leads to a short CuCu distance, the tbutyl ...
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Chemical Engineering, Inorganic Chemistry, Water, Electrochemistry, Catalysis, and 10 moreInorganic, Magnetic Resonance Spectroscopy, Macromolecular X-Ray Crystallography, Copper, Structure activity Relationship, Organometallic Compounds, Hydrogen-Ion Concentration, Ligands, Oxidation-Reduction, and Molecular Structure
The Cu(I) and Cu(II) complexes of the new 1,8-diferro-cenylmethyl-4,11-dimethyl-1,4,8,11-tetraazacyclotetra-decane ligand (denoted L) have been isolated and characterized by X-ray structure determination and electrochemical studies. The... more
The Cu(I) and Cu(II) complexes of the new 1,8-diferro-cenylmethyl-4,11-dimethyl-1,4,8,11-tetraazacyclotetra-decane ligand (denoted L) have been isolated and characterized by X-ray structure determination and electrochemical studies. The Cu(I) complex presents an unprecedented stability toward dioxygen. The two complexes adopt two energetically distinct and stable geometries, which differ mainly by the relative positioning of the substituents above or below the cyclam plane. Triggered by a copper-centered electron transfer, a fast and reversible motion of the noncoordinating subunits is obtained in homogeneous solution and in the solid state.
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The new bis(ferrocene)-cyclam macrocycle 1,8-bis(ferrocenylmethyl)-1,4,8,11-tetraazacyclotetradecane, denoted L, has been synthesized. Two Cu(II) complexes with L have been isolated and characterized from X-ray structure determination and... more
The new bis(ferrocene)-cyclam macrocycle 1,8-bis(ferrocenylmethyl)-1,4,8,11-tetraazacyclotetradecane, denoted L, has been synthesized. Two Cu(II) complexes with L have been isolated and characterized from X-ray structure determination and electrochemical studies. These two LCu(II) complexes correspond to the type I (ferrocenyl subunits in the same side of the cyclam plane) and type III (ferrocenyl subunits above and below the cyclam plane) isomers. The type I LCu(II) complex was synthesized from L and a Cu(2+) salt, while the type III isomer was obtained by oxidation in air or by comproportionation of the Cu(I) complex. The interconversion between type I and type III LCu(II) complexes is negligible in acetonitrile and slow in dimethyl sulfoxide but fast via an electrochemical reduction-reoxidation cycle. According to UV-vis and electrochemical characterizations, the type III isomer is thermodynamically more stable and the type I isomer is kinetically favored. A type III LNi(II) complex was also isolated and characterized by X-ray diffraction analysis and from electrochemical studies.
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Soluble homo- and heterometallic coordination polymers containing transition metal cations (Cu(2+), Fe(2+), Co(2+), and Ni(2+) ions) were prepared in a two-step procedure using a polytopic bis(terpyridine)dioxocyclam ligand 1H(2)... more
Soluble homo- and heterometallic coordination polymers containing transition metal cations (Cu(2+), Fe(2+), Co(2+), and Ni(2+) ions) were prepared in a two-step procedure using a polytopic bis(terpyridine)dioxocyclam ligand 1H(2) (dioxocyclam = 1,4,8,11-tetraazacyclotetradecane-5,7-dione). These supramolecular systems incorporate two different metal complexes, the metal cations being located both between two terpyridine units and in the macrocyclic framework. The characterization of these soluble architectures was investigated by cyclic voltammetry, mass spectrometry, viscosimetry, and UV-vis absorption and electron paramagnetic resonance (EPR) spectroscopies. Our results clearly indicate the formation of well-organized heterometallic polymers in which two different metal ions alternate in the self-assembled structure. These investigations furthermore brought to light an original acid-controlled disassembling process of the homometallic copper(II) polymer into dinuclear complexes.
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The dinucleating ligand 2,6-bis[(bis(2-pyridylmethyl)amino)methyl]-4-methylphenol (H-BPMP) has been used to synthesize the three dinuclear Cu(II) complexes [Cu2(BPMP)(OH)][ClO4](2).0.5C4H8O (1), [Cu2(BPMP)(H2O)2](ClO4)(3).4H2O (2), and... more
The dinucleating ligand 2,6-bis[(bis(2-pyridylmethyl)amino)methyl]-4-methylphenol (H-BPMP) has been used to synthesize the three dinuclear Cu(II) complexes [Cu2(BPMP)(OH)][ClO4](2).0.5C4H8O (1), [Cu2(BPMP)(H2O)2](ClO4)(3).4H2O (2), and [Cu2(H-BPMP)][(ClO4)4].2CH3CN (3). X-ray diffraction studies reveal that 1 is a mu-hydroxo, mu-phenoxo complex, 2 a diaqua, mu-phenoxo complex, and 3 a binuclear complex with Cu-Cu distances of 2.96, 4.32, and 6.92 A, respectively. Magnetization measurements reveal that 1 is moderately antiferromagnetically coupled while 2 and 3 are essentially uncoupled. The electronic spectra in acetonitrile or in water solutions give results in accordance with the solid-state structures. 1 is EPR-silent, in agreement with the antiferromagnetic coupling between the two copper atoms. The X-band spectrum of powdered 2 is consistent with a tetragonally elongated square pyramid geometry around the Cu(II) ions, in accordance with the solid-state structure, while the spectrum in frozen solution suggests a change in the coordination geometry. The EPR spectra of 3 corroborate the solid-state and UV-visible studies. The 1H NMR spectra also lead to observations in accordance with the conclusions from other spectroscopies. The electrochemical behavior of 1 and 2 in acetonitrile or in water solutions shows that the first reduction (Cu(II)Cu(II)-Cu(II)Cu(I) redox couple) is reversible and the second (formation of Cu(I)Cu(I) irreversible. In water, 1 and 2 are reversibly interconverted upon acid/base titration (pK 4.95). In basic medium a new species, 4, is reversibly formed (pK 12.0), identified as the bishydroxo complex. Only 1 exhibits catecholase activity (oxidation of 3,5-di-tert-butylcatechol to the corresponding quinone, vmax = 1.1 x 10(-6) M-1 s-1 and KM = 1.49 mM). The results indicate that the pH dependence of the catalytic abilities of the complexes is related to changes in the coordination sphere of the metal centers.
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... 4-Ferrocenylbutyric acid (7) has previously been prepared by the reaction of ferrocene with succinic anhydride followed by a Clemmensen reduction.32 We report here an alternative approach from ferrocene in four steps with a 50 %... more
... 4-Ferrocenylbutyric acid (7) has previously been prepared by the reaction of ferrocene with succinic anhydride followed by a Clemmensen reduction.32 We report here an alternative approach from ferrocene in four steps with a 50 % overall yield. ... 1 PD Beer , PA Gale , Angew. ...
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ABSTRACT The coordinative properties of mono(bipy) and bis(bipy) (bipy refers to 6- or 6,6′-substituted 2,2′-bipyridine) carbonyloxy- and carboxamido-bridged derivatives of ferrocene L1−5 towards a number of metal cations (CuI, CuII,... more
ABSTRACT The coordinative properties of mono(bipy) and bis(bipy) (bipy refers to 6- or 6,6′-substituted 2,2′-bipyridine) carbonyloxy- and carboxamido-bridged derivatives of ferrocene L1−5 towards a number of metal cations (CuI, CuII, NiII, FeII, CoII, HgII, PbII, AgI) have been investigated by the interplay of voltammetry, mass spectrometry and X-ray diffraction studies. Particular attention was paid to the electrochemical recognition properties of these redox-active ligands, as monitored by modulation of the ferrocene/ferricinium redox couple upon complexation. It was found that the bis(bipy)-bridged ligands exhibit a sandwich effect that gives rise to a well-behaved voltammetric wave for the ferrocene fragment as an elegant signature of complexation. The ferrocenyl ester-bridged bis(bipy) ligand L2 forms a 2:2 complex in the solid state with CuI, while the crystal structure of the CuII complex reveals 1:1 stoichiometry. Upon dissolution, the 2:2 species dissociate rapidly into the [CuL2]+ complex. Finally, electrochemical and FAB-MS data have been used to conclude that these ferrocenyl ligands bind to iron(II) to generate unusual [Fe(bipy)2]2+-type complexes. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)
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Viologen-based redox-switchable anion-binding receptors. Ramu Kannappana, Christophe Bucher*a, Eric Saint-Aman*a, Jean-Claude Mouteta, Anne Miletb, Mircea Olteanb, Estelle Métayc, Stéphane Pellet-Rostaingc, Marc Lemairec and Carole... more
Viologen-based redox-switchable anion-binding receptors. Ramu Kannappana, Christophe Bucher*a, Eric Saint-Aman*a, Jean-Claude Mouteta, Anne Miletb, Mircea Olteanb, Estelle Métayc, Stéphane Pellet-Rostaingc, Marc Lemairec and Carole Chaixd. ...
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... Guy Serratrice 1 ,; Jean-Baptiste Galey 3 ,; Eric Saint Aman 2 ,; Jacqueline Dumats 3. ... conditions associated with so-called oxidative stress, ie when traces of iron are locally released from their normal storage sites and become... more
... Guy Serratrice 1 ,; Jean-Baptiste Galey 3 ,; Eric Saint Aman 2 ,; Jacqueline Dumats 3. ... conditions associated with so-called oxidative stress, ie when traces of iron are locally released from their normal storage sites and become available to catalyze Fenton chemistry, leading to ...
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Contribution ffom the Luboratoire de Chimie BiomimCtique, LEDSS (URA CNRS 332) and Luboratoire d'Electrochimie Organique et de Photochimie Redox (URA CNRS 1210), Universiti Joseph Fourier, BP 53, 38041 Grenoble Cedex... more
Contribution ffom the Luboratoire de Chimie BiomimCtique, LEDSS (URA CNRS 332) and Luboratoire d'Electrochimie Organique et de Photochimie Redox (URA CNRS 1210), Universiti Joseph Fourier, BP 53, 38041 Grenoble Cedex 9, France, and Luboratoire DRFMC/SESAM/CC, ...
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The heterodinuclear Zn II Fe III complex 1 and the isostructural Fe II Fe III complex 2 with the dinucleating ligand from 2,6-bis[{bis(2-pyridylmethyl)amino}methyl]-4-methoxyphenol (HBPMOP, 3) were prepared and characterized by X-ray... more
The heterodinuclear Zn II Fe III complex 1 and the isostructural Fe II Fe III complex 2 with the dinucleating ligand from 2,6-bis[{bis(2-pyridylmethyl)amino}methyl]-4-methoxyphenol (HBPMOP, 3) were prepared and characterized by X-ray crystallography. Solution studies ...
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ABSTRACT Based on ion-pairing interactions, which are strongly reinforced upon oxidation to their ferrocenium form, (ferrocenylmethyl)trialkylammonium cations are able to electrochemically sense dihydrogenphosphate and ATP anions in... more
ABSTRACT Based on ion-pairing interactions, which are strongly reinforced upon oxidation to their ferrocenium form, (ferrocenylmethyl)trialkylammonium cations are able to electrochemically sense dihydrogenphosphate and ATP anions in organic electrolytes through two-wave voltammetric features, allowing their amperometric titration. The successful transfer of these electrochemical sensing properties from the homogeneous phase to an electrode surface was achieved using functionalized polypyrrole films synthesized by oxidative polymerization of pyrrole-containing (ferrocenylmethyl)trialkylammonium derivatives.