Hyperbranch‐polyethyleniminated functional polymers. I. Synthesis,characterization of novel ABA type of dumbbell‐like polyethyleniminated polyoxypropylenediamines,and their complexing properties with copper(II) ions in aqueous solution

Novel ABA‐type dumbbell‐like water‐soluble copolymers [D230(EI)₄, D400(EI)₄, and D400(EI)₈] were synthesized by introducing ethylenimine (EI) groups into both sides of polyoxypropylenediamines via a simple in situ ethylamination of polyoxypropylenediamine with 2‐chloroethylamine hydrochloride. The structures of the resultant polymers were identified by Fourier transform infrared spectroscopy and ¹H NMR. The percentages of primary, secondary, and tertiary amine present were determined by the potentiometric titration method after treatments with the appropriate chemicals of salicylaldehyde and acetic anhydride. The surface tension and solubilizing behavior of pyrene in the presence of these polymers in aqueous medium were also investigated, and the efficiency to reduce the surface tension and solubilizing behavior of pyrene depends on the attachments of EI to polymer backbone. The chelating properties of these polymers were examined quantitatively by ultraviolet–visible (UV–vis) spectroscopy in the presence of Cu²⁺ ions in aqueous solution, and continuous variation analysis revealed that the most stable complex is formed at the normality ratio of [N]/[Cu²⁺] = 3.0. UV–vis spectroscopy and transmission electron microscopy were used to evaluate the dumbbell‐like water‐soluble copolymer, D400(EI)₈, as a stabilizer for preparing colloidal noble metal nanoparticles (Au and Pt) in aqueous solution. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1360–1370, 2003     

Hyperbranched‐polyethyleneiminated functional polymers. III. Synthesizing thiophosphate‐containing pseudodendritic poly‐ethyleneiminated polyoxypropylenediamine and its behavior at an oil/metal interface under extreme pressure

A simple synthetic route for preparing a thiophosphate‐containing pseudodendritic polyethyleneiminated polyoxypropylenediamine, D400(EI)_xP, is presented. The number of ethyleneimine group (EI) in D400(EI)_xP was determined by ¹H‐ and ¹³C‐NMR to be 4.3 for D400(EI)₄P and 8.9 for D400(EI)₈P, and the extent of branch was quantitatively determined using potentiometric titration. The numbers of thiophosphate groups per thiophosphate‐containing pseudodendritic polymers molecule for D400(EI)₀P, D400(EI)₄P, and D400(EI)₈P were calculated by elemental analyses of sulfur content. The AW performance of these synthesized thiophosphate‐containing pseudodendritic polymers was examined by measuring the temperature of oil, and the frictional coefficient and electrical contact resistance between the two metal surfaces. More thiophosphate groups on either side of D400(EI)₈P are found to increase the electrical contact resistance due to the chemical adsorption of thiophosphate groups onto metal surfaces, forming a thick layer and reducing operating time required to form the adsorption layer. Interestingly, the adsorption layers markedly reduce the frictional coefficient (～ 0.012) and limit the increase in oil temperature (～ 90 °C) throughout the entire period of AW test, reducing weight loss of the metal (0.1 mg). © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5504–5513, 2004     

Effect of alkyl substituents structures and added ions on the phase transition of polymers and gels prepared from methyl 2‐alkylamidoacrylates

The effects of structure alteration of alkyl groups and addition of ions to solutions of new thermosensitive polymer series of poly(methyl 2‐alkylamidoacrylate)s were investigated. Potential advantages of the thermosensitive polymers are their simplicity of functionalization and transition temperature control that result from their unique α,α‐disubstituited structures. Poly(methyl 2‐propionamidoacrylate) (PMPA) and poly(methyl 2‐isobutyracrylate) (PMIBA) were thermosensitive polymers, and poly(methyl 2‐acetamidoacrylate) and poly(methyl 2‐n‐butyramidoacrylate) were completely water‐soluble and ‐insoluble, respectively. The PMIBA solution showed endotherm during the phase transition, while endotherm was not detected for PMPA. The difference between the two polymers resulted from the size of the hydrophobic groups. MPA gel was prepared by copolymerization with N,N′‐methylenebis(acrylamide) and temperature‐induced volume change of the gel was continuous. The salting‐out effect of inorganic ions on PMPA solution and MPA gel followed the Hofmeister series. The inorganic (I^? and SCN^?) and organic ions (ⁿPr₄N⁺ and ⁿBu₄N⁺), which showed the salting‐in effect, were indicated to directly interact with PMPA chains. These ions widened the temperature range of the phase transition of the PMPA solutions. This reduced cooperativity of the phase transition was caused by size decrease of cooperative domains, which resulted from the interaction of the ions with the polymer. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4942–4952, 2005     

Zinc(II) Complexes with 1H‐Imidazol‐4‐yl‐Containing Polyamine Ligand

The protonation and Zn^II/Cu^II complexation constants of tripodal polyamine ligand N¹‐(2‐aminoethyl)‐N¹‐(1H‐imidazol‐4‐ylmethyl)‐ethane‐1,2‐diamine (HL) were determined by potentiometric titration. Three new compounds, i.e. [H₃(HL)](ClO₄)₃ ( 5 ), [Zn(HL)Cl](ClO₄) ( 6 ) and {[Zn(L)](ClO₄)}_n ( 7 ) were obtained by reactions of HL · 4HCl with Zn(ClO₄)₂ · 6H₂O under different reaction pH, and they were compared with the corresponding Cu^II complexes reported previously. The results indicate that the reaction pH and metal ions have remarkable influence on the formation and structure of the complexes.     

Silver(I)‐Selective PVC Membrane Potentiometric Sensor Based on a Recently Synthesized Calix[4]arene

A new PVC membrane potentiometric sensor for Ag(I) ion based on a recently synthesized calix[4]arene compound of 5,11,17,23‐tetra‐tert‐butyl‐25,27‐dihydroxy‐calix[4]arene‐thiacrown‐4 is developed. The electrode exhibits a Nernstian response for Ag(I) ions over a wide concentration range (1.0×10^?2?1.0×10^?6 M) with a slope of 53.8±1.6 mV per decade. It has a relatively fast response time (5–10 s) and can be used for at least 2 months without any considerable divergence in potentials. The proposed electrode shows high selectivity towards Ag⁺ ions over Pb²⁺, Cd²⁺, Co²⁺, Zn²⁺, Cu²⁺, Ni²⁺, Sr²⁺, Mg²⁺, Ca²⁺, Li⁺, K⁺, Na⁺, NH₄⁺ ions and can be used in a pH range of 2–6. Only interference of Hg²⁺ is found. It is successfully used as an indicator electrode in potentiometric titration of a mixture of chloride, bromide and iodide ions.     

Comparative study of electrostatic binding vs. complexation of Cu2+ ions with water‐soluble polymers containing styrene sulphonic acid and/or maleic acid units or their sodium salt forms

The interaction of Cu²⁺ ions with the homopolymer poly(styrene sulfonic acid) (PSSH), as well as with the copolymers of maleic acid (MAc) with styrene sulfonic acid (SSH) or vinyl acetate (VAc), was investigated in dilute aqueous solution through turbidimetry, potentiometry, viscometry, and spectrophotometry in the visible region. Cu²⁺ ions were introduced either through neutralization with Cu(OH)₂ of the acid form of the (co)polymers (PSSH, P(SSH‐co‐MAc) and P(VAc‐co‐MAc)) or through mixing of the sodium salt form of the (co)polymers (PSSNa, P(SSNa‐co‐MANa) and P(VAc‐co‐MANa)) with CuSO₄. Turbidimetry, potentiometry, and spectrophotometry revealed that the first carboxylic group of MAc or both carboxylate groups of MANa are involved in the complexation with Cu²⁺ ions when neutralization with Cu(OH)₂ or mixing with CuSO₄ are applied, respectively. The increased values of the reduced viscosity observed mainly at the first stages of neutralization of P(VAc‐co‐MAc) with Cu(OH)₂ indicate that interchain polymer‐Cu²⁺ complexation takes possibly place. Finally, the spectrophotometric behavior observed upon neutralization of P(SSH‐co‐MAc) with Cu(OH)₂ or mixing of P(SSNa‐co‐MANa) with CuSO₄ revealed that the strength of counterion binding by the sulfonate groups is, in fact, comparable with the complexation of Cu²⁺ ions with the carboxylate groups of MAc. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1149–1158, 2008     

New sulfonate-containing network polymers based on immobilized <Emphasis Type="Italic">cis</Emphasis>-metacyclophane-3,5,10,12,17,19,24,26-octols

Polymeric metacyclophaneoctol-based sulfonic acids have been synthesized, and their ion-exchange properties have been studied. New polymeric sulfonic acids have been obtained through the sulfonation of network polymers based on immobilized cis-metacyclophane-3,5,10,12,17,19,24,26-octols. The structure of the polymers has been investigated by means of IR spectroscopy, potentiometric titration, and elemental analysis. The polymers thus obtained possess a high ion-exchange capacity with respect to Na⁺, Cu²⁺, [Pd(NH₃)₄]²⁺, and In³⁺ cations in a wide pH range. Selectivity coefficients of Na⁺-H⁺, Cu²⁺-H⁺, and In³⁺-H⁺ ion exchange have been estimated.     

Competitive binding exchange between alkali metal ions (K+, Rb+, and Cs+) and Na+ ions bound to the dimeric quadruplex [d(G4T4G4)]2: a 23Na and 1H NMR study

A comparative study of the competitive cation exchange between the alkali metal ions K⁺, Rb⁺, and Cs⁺ and the Na⁺ ions bound to the dimeric quadruplex [d(G₄T₄G₄)]₂ was performed in aqueous solution by a combined use of the ²³Na and ¹H NMR spectroscopy. The titration data confirm the different binding affinities of these ions for the G‐quadruplex and, in particular, major differences in the behavior of Cs⁺ as compared to the other ions were found. Accordingly, Cs⁺ competes with Na⁺ only for the binding sites at the quadruplex surface (primarily phosphate groups), while K⁺ and Rb⁺ are also able to replace sodium ions located inside the quadruplex. Furthermore, the ¹H NMR results relative to the CsCl titration evidence a close approach of Cs⁺ ions to the phosphate groups in the narrow groove of [d(G₄T₄G₄)]₂. Based on a three‐site exchange model, the ²³Na NMR relaxation data lead to an estimate of the relative binding affinity of Cs⁺ versus Na⁺ for the quadruplex surface of 0.5 at 298 K. Comparing this value to those reported in the literature for the surface of the G‐quadruplex formed by 5′‐guanosinemonophosphate and for the surface of double‐helical DNA suggests that topology factors may have an important influence on the cation affinity for the phosphate groups on DNA. Copyright © 2009 John Wiley & Sons, Ltd.     

Photochromism and decolorization controlled by auxiliary ligands of complexes derived from 1‐methyl‐4,4′‐bipyridinium cation

Three 1‐methyl‐4,4′‐bipyridinium (MQ⁺)‐based complexes, {[Cd(MQ)(p‐BDC)Br]?H₂O}_n ( 1 ), {[Cd(MQ)(m‐BDC)(H₂O)Br]?3H₂O}_n ( 2 ) and Cu(MQ)Br₂ ( 3 ) (p‐H₂BDC = 1,4‐benzenedicarboxylic acid, m‐H₂BDC = 1,3‐benzenedicarboxylic acid), have been synthesized and structurally characterized. Compounds 1 and 2 are one‐dimensional coordination polymers constituted of one coordinated MQ⁺ cation, one coordinated Br^? ion and chains of Cd²⁺ ions connected by deprotonated BDC^2? units, which both have photochromism but different decolorization behaviors. The structures and photoresponsive behaviors controlled by auxiliary ligands have been explored. Compound 3 is constituted of one Cu⁺ center, one MQ⁺ ligand and two coordinated Br^? ions in a ‘V’ configuration, exhibiting no photochromism.     

Synthesis,characterization, and ion‐complexing properties of polymers displaying densely packed arrays of crown‐ethers as lateral substituents

We report the synthesis and ion‐binding properties of four poly(crown‐ethers) displaying either one or two crown‐ethers (15‐crown‐5 or 18‐crown‐6) on every third carbon alongside the backbone. The polymers were synthesized by living anionic ring‐opening polymerization of disubstituted cyclopropane‐1,1‐dicarboxylates monomers. Cation binding of the polychelating polymers and corresponding monomers to Na⁺ and K⁺ was evaluated by picrate extraction and isothermal calorimetry titration. This novel family of poly(crown‐ethers) demonstrated excellent initial binding of the alkali ions to the polymers, with a higher selectivity for potassium. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2337–2345     

Studies on the equilibrium among poly(sodium 4‐styrenesulfonate), Cu2+, and iminodiacetic acid by ultrafiltration at constant ionic strength

The ultrafiltration technique evaluates the interactions of water‐soluble polymers with metal ions. Aqueous solutions containing poly(sodium 4‐styrenesulfonate) (PSS), Cu(NO₃)₂, NaNO₃, and iminodiacetic acid (IDAA) are examined by this technique. Cu²⁺ undergoes complex formation with IDAA and intreracts electrostatically with PSS. On the other hand, Na⁺ ions are in competition with Cu²⁺ for the electrostatic binding to PSS. The solutions are ultrafiltered keeping the ionic strength constant, so their compositions are allowed to change continuously. The concentration of Cu²⁺ bound to the polymer showed an exponential decay during filtration. The concentration of Cu²⁺ bound to the polymer before ultrafiltration is calculated by extrapolation. The concentration of the different species in solution is proposed as a function of the filtration factor. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 2587–2593, 2002     

An Easy Process to Prepare a Copper(I)/Copper Sulfide Electrode and Its Behavior in Alkalimetric Titrations

Abstract

A copper sulfate (Cu₂S) film is formed on the surface of a copper wire by immersion in melted (>55°C) sodium thiosulfate, Na₂S₂O₃·5H₂O. This Cu₂S/Cu electrode is sensitive to sulfide ions and can be used in potentiometric titration of Na₂S solutions with copper(II) cations. Besides, as a novelty, it gives a good response to H⁺ cations at a wide pH range, even in alkaline medium, as checked in potentiometric titration of acetic and phosphoric acids. An analysis of a number of potentiometric measurements leads to interpretation of the electrode response in acidic/basic medium.     

Low‐oxidation‐potential conducting polymers derived from 3,4‐ethylenedioxythiophene and dialkoxybenzenes

Monomers derived from 3,4‐ethylenedioxythiophene and phenylenes with branched or oligomeric ether dialkoxy substituents were prepared with the Negishi coupling technique. Electrooxidative polymerization led to the corresponding dialkoxy‐substituted 3,4‐ethylenedioxythiophene–phenylene polymers, with extremely low oxidation potentials (E_1/2,p = ?0.16 to ?0.50 V vs Ag/Ag⁺) due to the highly electron‐rich nature of these materials. The polymers were electrochromic, reversibly switching from red to blue upon oxidation, with bandgaps at about 2 eV. The electrochemical behavior of the oligomeric ether‐substituted polymer was investigated in the presence of different metal ions. Films of the polymer exhibited electrochemical recognition for several alkali and alkaline‐earth cations with selectivity in the order Li⁺ > Ba²⁺ > Na⁺ > Mg²⁺. Cyclic voltammetry showed a decrease in the oxidation potential and an improvement in the definition of the voltammetric response, as well as an increase in the overall electroactivity of the polymer films when the concentration of the cations in the medium was increased. These results are discussed in terms of the electrostatic interactions between the complexed cation and the redox center, as well as the diffusion of the ionic species into the polymer matrix. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2164–2178, 2001     

Synthesis of zwitterionic polymer by SET‐LRP at room temperature in aqueous

The Cu⁰‐mediated single electron transfer‐living radical polymerization of acrylamide and N,N‐dimethyl‐N‐methacryloyloxyethyl‐N‐sulfobutyl ammonium in aqueous at 25 °C using 2‐chloropropionamide as initiator with Cu⁰ powder/tris‐(2‐dimethylamino ethyl)amine (Me₆‐TREN) as catalyst system is studied. The results showed the characteristic of the “living” polymerization that were the M_n of polymers increased linearly with monomer conversion and the ln([M]₀/[M]) increased linearly with time too, meanwhile the narrow molecular of weight distributions were found at most cases. Because of the high rate constant of propagation and bimolecular termination of the acrylamide, the external addition of CuCl₂ is required to mediate deactivation the early stage of polymerization. In addition, the disproportionation constant of Cu^IX/L in H₂O is higher than in other solvents and the coordination of amino group and Cu^II takes place easily, so the isopropanol or N,N‐dimethylformamide is added to control the polymerization. High conversions were achieved within short time and the polymers prepared showed good antipolyelectrolyte properties in inorganic salts solutions. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Degradation of poly(acrylates) under SF5+ primary ion bombardment studied using time‐of‐flight secondary ion mass spectrometry. 2. Poly(n‐alkyl methacrylates)

Polyatomic primary ions offer low penetration depth and high damage removal rates in some polymers, facilitating their use in the molecular depth profiling of these polymers by secondary ion mass spectrometry (SIMS). This study is the second in a series of systematic characterizations of the effect of polymer chemistry on degradation under polyatomic primary ion bombardment. In this study, time‐of‐flight SIMS (ToF‐SIMS) was used to measure the damage of ～90 nm thick spin‐cast poly(methyl methacrylate), poly(n‐butyl methacrylate), poly(n‐octyl methacrylate) and poly(n‐dodecyl methacrylate) films under extended (～2 × 10¹⁴ ions cm^?2) 5 keV SF₅⁺ bombardment. The degradation of the poly(n‐alkyl methacrylates) were compared to determine the effect of the length of the alkyl pendant group on their degradation under SF₅⁺ bombardment. The sputter rate and stability of the characteristic secondary ion intensities of these polymers decreased linearly with alkyl pendant group length, suggesting that lengthening the n‐alkyl pendant group resulted in increased loss of the alkyl pendant groups and intra‐ or intermolecular cross‐linking under SF₅⁺ bombardment. These results are partially at variance with the literature on the thermal degradation of these polymers, which suggested that these polymers degrade primarily via depolymerization with minimal intra‐ or intermolecular cross‐linking. Copyright © 2004 John Wiley & Sons, Ltd.     

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.     

Water‐soluble hyperbranched polyelectrolytes with high fluorescence quantum yield: Facile synthesis and selective chemosensor for Hg2+ and Cu2+ ions

New water‐soluble hyperbranched polyfluorenes bearing carboxylate side chains have been synthesized by the simple “A2 + B2 + C3” protocol based on Suzuki coupling polymerization. The linear polyfluorene analogue LPFA was also synthesized for comparative investigation. The optical properties of the neutral precursory polymers in CHCl₃ and final carboxylic‐anionic conjugated polyelectrolytes in buffer solution were investigated. The obtained hyperbranched polyelectrolyte HPFA2 with lower content of branch unit (2%) showed excellent solubility and high fluorescence quantum yield (?_F = 89%) in aqueous solution. Fluorescence quenching of HPFA2 by different metal ions was also investigated, the polyelectrolyte showed high selectivity for Hg²⁺ and Cu²⁺ ions relative to other various metal ions in buffer solution. The Stern‐Volmer constant K_sv was determined to be 0.80 × 10⁶ M^?1 for Hg²⁺ and 3.11 × 10⁶ M^?1 for Cu²⁺, respectively, indicating the potential application of HPFA2 as a highly selective and sensitive chemosensor for Hg²⁺ and Cu²⁺ ions in aqueous solution. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3431–3439, 2010     

Cationic Complexes of Hydrogen with Helium

High‐resolution mass spectra of helium nanodroplets doped with hydrogen or deuterium reveal that copious amounts of helium can be bound to H⁺, H₂⁺, H₃⁺, and larger hydrogen‐cluster ions. All conceivable He_nH_x⁺ stoichiometries are identified if their mass is below the limit of ≈120 u set by the resolution of the spectrometer. Anomalies in the ion yields of He_nH_x⁺ for x=1, 2, or 3, and n≤30 reveal particularly stable cluster ions. Our results for He_nH₁⁺ are consistent with conclusions drawn from previous experimental and theoretical studies which were limited to smaller cluster ions. The He_nH₃⁺ series exhibits a pronounced anomaly at n=12 which was outside the reliable range of earlier experiments. Contrary to findings reported for other diatomic dopant molecules, the monomer ion (i.e. H₂⁺) retains helium with much greater efficiency than hydrogen‐cluster ions.     

Alkylhydrazides and their protonated forms: Physical methods andab initio calculations

The basicity of hydrazides of the highest aliphatic carboxylic acids RC(O)NHNH₂ (R = C_nH_2n+1,n = 5-12) has been studied by potentiometric titration, and IR and¹H NMR spectroscopy.Ab initio Hartree-Fork calculations using the 6–31G^* basis set with full optimization of geometry were carried out on the simplest acy1hydrazines and their possible protonated forms. Based on these calculations, and the 1R and¹H NMR spectra, the tautomerism of alkylhydrazides and the structures of their protonated forms are discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2645–2649, November, 1996.     

An ESR study of polymer-Cu(II) complexes in poly(vinyl alcohol), polyacrylamide,and poly(vinyl pyrrolidone) films

Optical and ESR spectra of polymer-Cu(II) complexes in polymer films have been studied. The dependence on F₁ = [Cu²⁺]/[MU] and F₂ = [OH^?]/[Cu²⁺], where [MU] is the molar concentration of monomeric units of the polymer, has been obtained. Optical spectra and potentiometric titration curves in solution have also been studied. There exists a buffer region 0 ? F₂ ? 2. Optical spectra in films are slightly different from those in solutions. At least five different ESR signals, designated as A, B, C or D, and E, have been found in poly(vinyl alcohol)-Cu(II). These signals appear successively with increasing F₂. Assignments are proposed as follows. Signal A (F₂ ≈ 0), also found in poly(acrylamide)-Cu(II) and poly(vinyl pyrrolidone)-Cu(II), is due to a single Cu(II) coordinated with two water molecules and chelated with two oxygens or nitrogens attached to the polymer. A chain of Cu(II) ions singly and double bridged with OH^? ions is responsible for the B signal (F₂ ≈ 1). The C and D signals (F₂ ≈ 2) appear to be caused, respectively, by a dimeric Cu(II) complex singly or doubly bridged with OH^? ions. The E signal (F₂ ≈ 7) appears to be due to a monomeric Cu(II) complex, different from that responsible for the A signal.