A New Fluorescent Chemosensor for Metal Ions Based upon 1,8‐Naphthalimide and 8‐Hydroxyquinoline

A new fluorescent chemosensor based upon 1,8‐naphthalimide and 8‐hydroxyquinoline was synthesized, and its fluorescent properties in the presence of different metal cations (Hg²⁺, Ag⁺, Zn²⁺, Fe²⁺, Cd²⁺, Pb²⁺, Ca²⁺, Cu²⁺, Mg²⁺, and Ba²⁺) were investigated. It displayed fluorescence quenching with some heavy and transition metal (HTM) ions, and the quenching strongly depended on the nature of HTM ions.     

Competitive heavy metal removal by poly(2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid‐co‐itaconic acid)

The competitive removal of Pb²⁺, Cu²⁺, and Cd²⁺ ions from aqueous solutions by the copolymer of 2‐acrylamido‐2‐methyl‐1‐propane sulfonic acid (AMPS) and itaconic acid (IA), P(AMPS‐co‐IA), was investigated. Homopolymer of AMPS (PAMPS) was also used to remove these ions from their aqueous solution. In the preparation of AMPS–IA copolymer, the molar percentages of AMPS and IA were 80 and 20, respectively. In order to observe the changes in the structures of polymers due to metal adsorption, FTIR spectra by attenuated total reflectancetechnique and scanning electron microscopy (SEM) pictures of the polymers were taken both before and after adsorption experiments. Total metal ion removal capacities of PAMPS and P(AMPS‐co‐IA) were 1.685 and 1.722 mmol Me²⁺/g_polymer, respectively. Experimental data were evaluated to determine the kinetic characteristics of the adsorption process. Competitive adsorption of Pb²⁺, Cu²⁺, and Cd²⁺ ions onto both PAMPS and P(AMPS‐co‐IA) was found to fit pseudo‐second‐order type kinetics. In addition, the removal orders in the competitive adsorption of these metal ions onto PAMPS and P(AMPS‐co‐IA) were found to be Cd²⁺ > Pb²⁺ > Cu²⁺ and Pb²⁺ > Cd²⁺ > Cu²⁺, respectively. Copyright © 2008 John Wiley & Sons, Ltd.     

A Bis‐Oxime Derivative of Diaza‐18‐Crown‐6 as an Ionophore for Silver Ion

A new pendant‐arm derivative of diaza‐18‐crown‐6, containing two oxime donor groups, has been synthesized and incorporated into a polyvinyl chloride (PVC) membrane ion‐selective electrode. The electrode shows selectivity for Ag⁺ ion, with a near Nernstian response. Pb²⁺, Cu²⁺, Hg²⁺, and Tl⁺ are major interfering ions, with Cd²⁺ having minor interference. The electrode shows no potentiometric response for the ions Mg²⁺, Al³⁺, K⁺, Ca²⁺, Ni²⁺, Fe³⁺, and La³⁺, and is responsive to H⁺ at pH<6.     

A novel blue fluorescent chemosensor for metal cations and protons,based on 1,8‐naphthalimide and its copolymer with styrene

A new blue emitting 2‐allyl‐6‐(2‐dimethylaminoethyloxy)‐benzo[de]isoquinoline‐1,3‐dione, bearing an allylic group has been designed and synthesized. Bulk radical copolymerization has been carried out in order to prepare a fluorescent copolymer, based on styrene. The main photophysical characteristics of the monomeric and polymeric fluorophores have been investigated both in the absence and presence of metal cations and protons. It has been found that the monomeric naphthalimide can be used as a sensor for protons and Zn²⁺, Ni²⁺, Ce³⁺, Cu²⁺, Co²⁺, Ag⁺ cations. The polymeric fluorophore has been shown to be a selective chemosensor for Cu²⁺ cations. Copyright © 2006 John Wiley & Sons, Ltd.     

Binding of Cu+ and Cu2+ with peptides: Peptides = oxytocin,Arg8‐vasopressin,bradykinin, angiotensin‐I,substance‐P,somatostatin, and neurotensin

The intrinsic binding ability of 7 natural peptides (oxytocin, arg⁸‐vasopressin, bradykinin, angiotensin‐I, substance‐P, somatostatin, and neurotensin) with copper in 2 different oxidation states (Cu^I/II) derived from different Cu^+/2+ precursor sources have been investigated for their charge‐dependent binding characteristics. The peptide‐Cu^I/II complexes, [M − (n‐1)H + nCu^I] and [M − (2n‐1)H + nCu^II], are prepared/generated by the reaction of peptides with CuI solution/Cu‐target and CuSO₄ solution and are analyzed by using matrix‐assisted laser desorption/ionization (MALDI) time‐of‐flight mass spectrometry. The MALDI mass spectra of both [M − (n‐1)H + nCu^I] and [M − (2n‐1)H + nCu^II] complexes show no mass shift due to the loss of ─H atoms in the main chain ─NH of these peptides by Cu⁺ and Cu²⁺ deprotonation. The measured m/z value indicates the reduction of Cu^I/II oxidation state into Cu⁰ during MALDI processes. The number and relative abundance of Cu⁺ bound to the peptides are greater compared with the Cu²⁺ bound peptides. Oxytocin, arg⁸‐vasopressin, bradykinin, substance‐P, and somatostatin show the binding of 5Cu⁺, and angiotensin‐I and neurotensin show the binding of 7Cu⁺ from both CuI and Cu targets, while bradykinin shows the binding of 2Cu²⁺, oxytocin, arg⁸‐vasopressin, angiotensin‐I, and substance‐P; somatostatin shows the binding of 3Cu²⁺; and neurotensin shows 4Cu²⁺ binding. The binding of more Cu⁺ with these small peptides signifies that the bonding characteristics of both Cu⁺ and Cu²⁺ are different. The amino acid residues responsible for the binding of both Cu⁺ and Cu²⁺ in these peptides have been identified based on the density functional theory computed binding energy values of Cu⁺ and the fragment transformation method predicted binding preference of Cu²⁺ for individual amino acids.     

5,5′‐Hydrazinebistetrazole: An Oxidation‐stable Nitrogen‐rich Compound and Starting Material for the Synthesis of 5,5′‐Azobistetrazolates

All 5,5′‐hydrazinebistetrazoles reported in the literature are sensitive to oxidation and react with atmospheric oxygen to yield the corresponding 5,5′‐azobistetrazolates on time. Herewith, we report on the synthesis of the free acid 5,5′‐hydrazinebistetrazole (HBT) which showed to be stable on air for extended periods of time. The compound was fully characterized by analytical and spectroscopic methods and its X‐ray structure was determined by diffraction techniques. Besides, we determined its explosive properties by BAM methods and calculated its heat of formation (+414 kJ mol^?1), detonation velocity (8523 m s^?1) and detonation pressure (27.7 GPa). HBT proved to be very safe to handle (impact sensitivity: >30 J, friction sensitivity: ～108 N) and was used as a starting material for the synthesis of some already reported 5,5′‐azobistetrazolates: NH₄⁺, NH₂NH₃⁺, Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺, Mg²⁺, Ca²⁺, Sr²⁺ and Ba²⁺.     

Highly Selective All‐Plastic,Disposable, Cu2+‐Selective Electrodes

Conducting polymers (CP) remain a promising material to construct stable potential all‐solid‐state ion‐selective potentiometric electrodes. The unique properties of poly(3,4‐ethylenedioxythiophene) doped with poly(4‐styrenesulfonate) ions, PEDOT‐PSS: high CP stability and affinity of doping anions towards Cu²⁺ ions, make it highly attractive for construction of all‐solid‐state copper(II)‐selective electrodes with outstanding selectivity. The additional benefits can arise from solution processability of commercially available PEDOT‐PSS system. This material was highly promising for a new sensor arrangement, i.e. to obtain disposable, planar and flexible all‐plastic Cu²⁺‐selective electrodes. These sensors can be obtained by casting a commercially available dispersion of PEDOT‐PSS (Baytron P) on a plastic, non‐conducting support material. The CP being both electrical lead and ion‐to‐electron transducer, was covered with plastic, solvent polymeric Cu²⁺ selective membrane. This extremely simple arrangement, after conditioning in dilute Cu²⁺ solution, was characterized with linear Nernstian responses within the activities range from: 0.1 to 10^?4 M, followed by super‐Nernstian responses for lower activities. The latter result points to effective elimination of primary ions leakage from the plastic membrane / transducer phase and has resulted in significantly improved selectivities. Obtained log K values were equal to ?7.6 for Co²⁺, ?7.4 for Zn²⁺, ?7.2 for Ca²⁺ and ?6.8 for Na⁺, respectively.     

Highly Efficient and Selective Membrane Transport of Silver(I) Using Dibenzodiaza‐15‐Crown‐4 as a Selective Ion Carrier

A chloroform membrane system containing dibenzodiaza‐15‐crown‐4 was found to be a highly efficient and selective transport of Ag⁺ ions through a chloroform liquid membrane. In the presence of thiosulfate ion as a suitable ion stripping agent in the receiving phase, the amount of silver transported across the liquid membrane after 105 minis 95 ± 1.3%. The selectivity of Ag⁺transport from aqueous solutions containing Tl⁺, Pb²⁺, Cd²⁺, Ni²⁺, Co²⁺, K⁺, Ca²⁺, Sr²⁺, Hg²⁺, Zn²⁺, Cu²⁺was investigated. The interfering effect of Cu²⁺ ions was drastically diminished in the presence of EDTA as a proper masking agent in the source phase.     

Synthesis of Novel 4‐((Substituted bis‐indolyl)methyl)‐benzo‐15‐crown‐5 for the Colorimetric Detection of Hg2+ Ions in an Aqueous Medium

A practical, two‐step synthesis of novel 4‐(substituted bis‐indolyl)methyl)benzo‐15‐crown‐5 has been reported. The strategy employed for the synthesis of the desired molecules involved Duff formylation of benzo‐15‐crown‐5 to get 4‐formyl benzo‐15‐crown‐5 followed by subsequent reactions with substituted indoles in trifluoroacetic acid to yield novel 4‐(substituted bis‐indolyl)methyl)benzo‐15‐crown‐5 in moderate to good yield. One of the reported novel molecule tested for the complexation behavior with various metal cations, such as Li⁺, Na⁺, K⁺, Mg²⁺ Ca²⁺, Al³⁺, Fe²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺, Cd²⁺, Sn²⁺, Ba²⁺, Hg²⁺, and Pb²⁺, showed a visual colorimetric probe for the detection of mercury cations (Hg²⁺) in an aqueous medium.     

Synthesis of 8‐hydroxyquinolium chloroacetate and synthesis of complexes derived from 8‐hydroxyquinoline,and characterization,density functional theory and biological studies

8‐Hydroxyquinolium chloroacetate ( L¹ ) was synthesized and characterized. The results suggest that L¹ loses ethyl chloroacetate ion on coordination at low pH (2–5) and consequently it behaves as 8‐hydoxyquinoline ( L² ). Cu²⁺, Co²⁺, Pt⁴⁺, Pd²⁺, Au³⁺, Ag⁺ and Nd³⁺ complexes derived from L² have been synthesized and characterized using spectral, magnetic and thermal measurements. L² acts as a neutral bidentate ligand in the case of Cu²⁺, Co²⁺, Pt⁴⁺, Pd²⁺ and Nd³⁺ complexes and as a mononegative bidentate ligand in the case of Au³⁺ and Ag⁺ complexes. Octahedral geometry is proposed for Cu²⁺, Co²⁺ (grey) and Pt⁴⁺ complexes and square‐planar for Co²⁺ (green), Pd²⁺ and Au³⁺ complexes. The bond lengths, bond angles, chemical reactivities, binding energies and dipole moments for all compounds were evaluated using density functional theory and molecular electrostatic potential for L¹ . Superoxide dismutase radical scavenger‐like activity and cytotoxic activity of the complexes towards HepG2 liver cancer cells has been screened. Cytotoxicity measurements show that Ag⁺ and Pd²⁺ complexes have the highest cytotoxic activity while L¹ , Cu²⁺, Co²⁺ (grey), Co²⁺ (green), Pt⁴⁺ and Nd³⁺ complexes have no cytotoxic activity. Copyright © 2015 John Wiley & Sons, Ltd.     

All Solid State Chromium(III) Selective Potentiometric Sensor Based on 2‐(1‐(2‐((3‐(2‐Hydroxyphenyl)‐1H‐pyrozol‐1‐yl)methyl)benzyl)‐1H‐pyrazol‐3‐yl)phenol

Highly selective all solid state electrochemical sensor based on a synthesized compound i.e. 2‐(1‐(2‐((3‐(2‐hydroxyphenyl)‐1H‐pyrozol‐1‐yl)methyl)benzyl)‐1H‐pyrazol‐3‐yl)phenol (I) as an ionophore has been prepared and investigated for the selective quantification of chromium(III) ions. The effect of various plasticizers, viz. dibutyl phosphonate (DBP), dibutyl(butyl) phosphonate (DBBP), nitrophenyl octyl ether (NPOE), tris‐(2‐ethylhexyl)phosphonate (TEP), tri‐butyl phosphonate (TBP), dioctyl phthalate (DOP), dioctyl sebacate (DOS), benzyl acetate (BA) and acetophenone (AP) along with anion excluders NaTPB (sodium tetraphenyl borate) and KClTPB (potassium(tetrakis‐4‐chlorophenyl)borate was also studied. The optimum composition of the best performing membrane contained (I):KClTPB:NPOE:PVC in the ratio 15 : 3 : 40 : 42 w/w. The sensor exhibited near Nernstian slope of 20.1±0.2 mV/decade of activity in the working concentration range of 1.2×10^?7–1.0×10^?1 M, and in a pH range of 3.8–4.5. The sensor exhibited a fast response time of 10 s and could be used for about 5 months without any considerable divergence in potentials. The proposed sensor showed very good selectivity over most of the common cations including Na⁺, Li⁺, K⁺, Cu²⁺, Sr²⁺, Ni²⁺, Co²⁺, Ba²⁺, Hg²⁺, Pb²⁺, Zn²⁺, Cs⁺, Mg²⁺, Cd²⁺, Al³⁺, Fe³⁺and La³⁺. The activity of Cr(III) ions was successfully determined in the industrial waste samples by using this sensor.     

Sensitive and Selective Fluorescent and Colorimetric Sensor for Ag+ Based on the Supramolecular Self‐Assembly in Semi‐Water

Specific recognition of ultratrace levels of ions in semi‐water using super‐quicker methods is still a challenge for environmental monitoring. Herein we report a fluorescent and colormetric sensor ( ZH ) based on supramolecular self‐assembly, whose structure was destroyed by the addition of ultratrace of silver ions. The process promoted either naked eye visible color changes or fluorescence intensity quenched in conjunction with a wide pH range. Systematic studies revealed very high selectivity (0.07 µmol/L) for silver ions, and other common cations, e.g ., Hg²⁺, Cu²⁺, Cd²⁺, Pb²⁺ had nearly no influence on the sensing behavior. This sensor also served as a multiple use of component in sensing materials by addition of I⁻ into the mixture of ZH and Ag⁺ (about 5 times). What's more, ZH containing filter paper emerged distinct color and fluorescence changes upon exposure to silver (Ag⁺), which could be used as a portable method to undertake field testing for Ag ⁺ .     

Membrane Transport of Pb(II) with a Cooperative Carrier Composed of Dibenzyldiaza‐18‐Crown‐6 and Palmitic Acid

A chloroform membrane system containing a given mixture of dibenzyldiaza‐18‐crown‐6 and palmetic acid was applied for transport of Pb²⁺ ions. The transport was capable of moving metal ions “uphill”. Thus, it was possible to follow the transfer of Pb(II) from the aqueous source phase to the organic layer and from the organic layer to the receiving phase. The effects of thiosulfate concentration in the receiving phase, palmetic acid and dibenzyldiaza‐18‐crown‐6 concentration in the organic phase on the efficiency of the transport system were examined. By using S₂O₃^2? ion as metal ion acceptor in the receiving phase, the amount of lead ion transport across the liquid membrane after 150 minutes is 96 ± 1.5%. The selectivity and efficiency of lead transport from aqueous solution containing Cu²⁺, Tl⁺, Ag⁺, Co²⁺, Ni²⁺, Mg²⁺, Zn²⁺, Hg²⁺, Cd²⁺, Ca²⁺ were investigated. In the presence of thiosulfate as a suitable masking agent in the source phase, the interfering effects of Ag⁺ and Cu²⁺ were diminished drastically.     

A Highly Copper‐Selective Ratiometric Fluorescent Sensor Based on BODIPY

A new ratiometric fluorescent sensor ( 1 ) for Cu²⁺ based on 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene (BODIPY) with di(2‐picolyl)amine (DPA) as ion recognition subunit has been synthesized and investigated in this work. The binding abilities of 1 towards different metal ions such as alkali and alkaline earth metal ions (Na⁺, K⁺, Mg²⁺, Ca²⁺) and other metal ions ( Ba²⁺, Zn²⁺, Cd²⁺, Fe²⁺, Fe³⁺, Pb²⁺, Ni²⁺, Co²⁺, Hg²⁺, Ag⁺) have been examined by UV‐vis and fluorescence spectroscopies. 1 displays high selectivity for Cu²⁺ among all test metal ions and a ～10‐fold fluorescence enhancement in I₅₈₂/I₅₅₈ upon excitation at visible excitation wavelength. The binding mode of 1 and Cu²⁺ is a 1:1 stoichiometry determined via studies of Job plot, the nonlinear fitting of the fluorometric titration and ESI mass.     

A Fluorescent Chemosensor for Al3+ Based on CO Isomerization Derivated from Curcumin

A simple and nontoxic fluorescent chemosensor of di‐O‐methyl curcumin has been prepared from curcumin. The sensor exhibited selective and sensitive fluorescent responses toward Al³⁺ over a wide range of metal ions, such as Mn²⁺, Ce³⁺, Pt²⁺, Sn⁴⁺, Hg⁺, Sb³⁺, K⁺, Ca²⁺, Mg²⁺, Ba²⁺, Cu²⁺, Ni²⁺, Na⁺, NH₄⁺, Ag⁺, Pb²⁺, Zn²⁺, Fe²⁺, Fe³⁺, Hg²⁺ and Cr³⁺ in ethanol/water. The free ligand showed quite weak fluorescence emission due to the isomerization of C?O double bond in the excited state, however, after addition of Al³⁺, fluorescence emission results in a prominent fluorescence enhancement.     

Metallkomplexe mit biologisch wichtigen Liganden. CLXVI Metallkomplexe mit Ferrocenylmethyl‐L‐cysteinat und 1,1′‐Ferrocenylbis‐(methyl‐L‐cysteinat) als Liganden

Metal Complexes of Biologically Important Ligands. CLXVI Metal Complexes with Ferrocenylmethylcysteinate and 1,1′‐Ferrocenylbis‐(methylcysteinate) as Ligands A series of complexes of transition metal ions ( Cr³⁺, Mn²⁺, Co²⁺, Ni²⁺, Cu²⁺, Zn²⁺ ) and of lanthanide ions ( La³⁺, Nd³⁺, Gd³⁺, Dy³⁺, Lu³⁺ ) with the anions of ferrocenylmethyl‐L‐cysteine [(C₅H₅)Fe(C₅H₄CH(R)SCH₂CH(NH₃⁺)CO₂^?] (L¹) and with the dianions of 1,1′‐ferrocenylbis(methyl‐L‐cysteine) [Fe(C₅H₄CH(R)SCH₂CH(NH₃⁺) CO₂^?)₂] (R = H, Me, Ph) (L²) as N,O,S‐donors were prepared. With the monocysteine ferrocene derivative L¹ as ligands complexes [M^IIL¹₂] or [Cr^IIIL¹₂]Cl type complexes are formed whereas the bis(cysteine) ligand L² yields insoluble complexes of type [ML²]_n, presumably as coordination polymers. The magnetic moments of [Mn^IIL²]_n, [Pr^IIIL²]_n(OH)_n and [Dy^IIIL²]_n(OH)_n exhibit “normal” paramagnetism.     

Bulk solvent‐free melt ring‐opening polymerization of L‐lactide catalyzed by Cu(II) and Cu(II)–Nd(III) complexes of the Salen‐type Schiff‐base ligand

A monometallic (Cu²⁺, 1) and a bimetallic (Cu²⁺ Nd³⁺, 2) Salen‐type Schiff‐base complexes with different reactive species, could efficiently catalyze the bulk solvent‐free melt ring‐opening polymerization (ROP) of L ‐lactide. Especially for the bimetallic complex 2, the involvement of rare earth ion was important and influential to the catalytic behaviors. Copyright © 2011 John Wiley & Sons, Ltd.     

A Dinuclear Ruthenium(II) Complex as a One‐ and Two‐Photon Luminescent Probe for Biological Cu2+ Detection

A new dinuclear Ru^II polypyridyl complex, [(bpy)₂Ru(H₂bpip)Ru(bpy)₂]⁴⁺ ( RuH₂bpip , bpy=2,2‐bipyridine, H₂bpip=2,6‐pyridyl(imidazo[4,5‐f][1,10]phenanthroline), was developed to act as a one‐ and two‐photon luminescent probe for biological Cu²⁺ detection. This Ru^II complex shows a significant two‐photon absorption cross section (400 GM) and displays a remarkable one‐ and two‐photon luminescence switch in the presence of Cu²⁺ ions. Importantly, RuH₂bpip can selectively recognise Cu²⁺ in aqueous media in the presence of other abundant cellular cations (such as Na⁺, K⁺, Mg²⁺, and Ca²⁺), trace metal ions in organisms (such as Zn²⁺, Ag⁺, Fe³⁺, Fe²⁺, Ni²⁺, Mn²⁺, and Co²⁺), prevalent toxic metal ions in the environment (such as Cd²⁺, Hg²⁺, and Cr³⁺), and amino acids, with high sensitivity (detection limit≤3.33×10^?8 M ) and a rapid response time (≤15 s). The biological applications of RuH₂bpip were also evaluated and it was found to exhibit low cytotoxicity, good water solubility, and membrane permeability; RuH₂bpip was, therefore, employed as a sensing probe for the detection of Cu²⁺ in living cells and zebrafish.     

A Copper(II) Ion‐Selective Potentiometric Sensor Based on N,N′,N″,N′′′‐Tetrakis(2‐pyridylmethyl)‐1,4,8,11‐tetraazacyclotetradecane in PVC Matrix

The simple PVC‐based membrane containing N,N′,N″,N′′′‐tetrakis(2‐pyridylmethyl)‐1,4,8,11‐tetraazacyclotetradecane (tpmc) as an ionophore and dibutyl phthalate as a plasticizer, directly coated on a glassy carbon electrode was examined as a new sensor for Cu²⁺ ions. The potential response was linear within the concentration range of 1.0×10^?1–1.0×10^?6 M with a Nernstian slope of 28.8 mV/decade and detection limit of 7.0×10^?7 M. The electrode was used in aqueous solutions over a wide pH range (1.3–6). The sensor exhibited excellent selectivity for Cu²⁺ ion over a number of cations and was successfully used in its determination in real samples.     

Syntheses,structures of N‐(substituted)‐2‐aza‐[3]‐ferrocenophanes and their application as redox sensor for Cu2+ ion

Rigid N‐(substituted)‐2‐aza‐[3]‐ferrocenophanes L1 and L2 were easily synthesized from 1,1 ‐dicarboxyaldehydeferrocene and the corresponding amines. Ligands L1 and L2 were characterized by ¹H NMR, ¹³C NMR and single‐crystal X‐ray crystallography. The coordination abilities of L1 and L2 with metal ions such as Cu²⁺, Mg²⁺, Ni²⁺, Zn²⁺, Pb²⁺ and Cd²⁺ were evaluated by cyclic voltammetry. The electrochemical shift (ΔE_1/2) of 125 mV was observed in the presence of Cu²⁺ ion, while no significant shift of the Fc/Fc + couple was observed when Mg²⁺, Ni²⁺, Zn²⁺, Pb²⁺, Cd²⁺ metal ions were added to the solution of L1 in the mixture of MeOH and H₂O. Moreover, the extent of the anodic shift of redox potentials was approximately equal to that induced by Cu²⁺ alone when a mixture of Cu²⁺, Mg²⁺, Ni²⁺, Zn²⁺, Pb²⁺ and Cd²⁺ was added to a solution of L1. Ligand L1 was proved to selectively sense Cu²⁺ in the presence of large, excessive first‐row transition and late‐transition metal cations. The coordination model was proposed from the results of controlled experiments and quantum calculations. Copyright © 2012 John Wiley & Sons, Ltd.