Iminodiacetic Acid Moieties Research Articles

Grafting chelating groups on 2D carbon for selective heavy metal adsorption.

Iminodiacetic acid (IDA) is a tridentate ligand, which can capture metal ions by forming two fused five-membered chelate rings. In this study, we fixed IDA moieties onto a two-dimensional nanocarbon, graphene oxide (GO), to obtain materials with high and selective adsorption of metal ions. The synthesis conditions for the GO–IDA composites were optimized, then their structures were characterized by infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and CHN elemental analysis. In addition, the heavy-metal removal efficiency and selectivity of the GO–IDA composites with different length alkyl linkers between the GO and IDA were investigated. An aqueous solution containing 10 metal ions (Al, As, B, Cd, Cr, Cu, Mn, Pb, Se, and Zn) was used as a model for contaminated water at pH 7, and the interactions of the ions with GO–IDA were in the order of Cu > Pb > As > B > Zn > Al ≈ Se. The interaction between Cu and GO–IDA was confirmed by XPS and extended X-ray absorption fine structure (EXAFS), which showed that Cu was coordinated to IDA.

Iminodiacetic Acid-Functionalized Gold Nanoparticles for Optical Sensing of Myoglobin via Cu2+Coordination

A novel gold nanoparticle (AuNP)-based optical sensing system has been developed for the detection of myoglobin (Mb), which is of significant importance for early disease diagnosis. Two thiol molecules containing an iminodiacetic acid moiety (IDA) were synthesized. This detection is based on the Mb-induced aggregation of IDA-functionalized AuNPs resulting from the structures of Mb sandwiched between the functionalized AuNPs via Cu(2+) bridges in the coordination interactions of IDA-Cu(2+)-histidine residues available on the Mb surface, which was confirmed by UV-vis spectroscopy, transmission electron microscopy, dynamic light scattering, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The induction aggregation resulted in a red shift in plasmon resonance band of the AuNPs concomitant with a change in solution color from red to purple. The qualitative and quantitative detections of Mb can be achieved by colorimetric observations and UV-vis spectral measurements, respectively. The selectivity of protein assay with the functionalized AuNPs was further investigated, and it is found that the optical sensing of histidine-rich proteins is closely related to number and distribution of surface histidine residues as well as size of proteins.

Development of luminescent Sm(III) chelates containing hexadentate to nonadentate ligands: synthesis, photophysical properties and coupling to biomolecules

Seventeen novel samarium (Sm)(III) chelates containing two iminodiacetic acid moieties were synthesised and their luminescence properties were measured with the aim of developing new labels for biochemical applications. The chelates contained different numbers of coordinating groups. According to the results obtained, the Sm(III) chelates that are to be used in time-resolved luminescence biochemical assays should be nonadentate in order to have a sufficient lifetime. Chelates having a terpyridine structure in the ligand seem to be promising alternatives. In addition, an equation for the determination of the number of water molecules in the first coordination sphere of Sm(III) ions in the chelate was developed.

Preparation of an iminodiacetic acid-modified capillary and its performance in capillary liquid chromatography and immobilized metal chelate affinity capillary electrophoresis

We prepared iminodiacetic acid (IDA)-modified and Cu(II)–IDA-modified capillaries through polymerization of N-(vinylbenzylimino)diacetic acid. The fundamental performance of these capillaries was examined in capillary liquid chromatography (LC) and immobilized metal chelate affinity capillary electrophoresis (IMACE). Copper(II), cobalt(II), and hematin were detected at different retention times by means of capillary LC with a chemiluminescence detector, during which the IDA-modified capillary was used. The difference in the retention times was attributed to the difference in the interaction between metal ions or complex and IDA moieties on the inner wall of the capillary. In addition, human serum albumin (HSA) and human serum γ-globulin (HγG) were separated and detected using IMACE with an absorption detector, during which the Cu(II)–IDA-modified capillary was used. The separation of HSA and HγG was achieved through the interaction between proteins and Cu(II) chelate moieties on the inner wall of this capillary.

Versatile routes to C-2- and C-6-functionalized glucose derivatives of iminodiacetic acid.

A series of novel d-glucose derivatives, functionalized at the C-2 or the C-6 position with an iminodiacetic acid moiety for transition-metal complexation, has been prepared. The sugar and the metal-chelating parts are separated by either propyl or octyl chains and were introduced by the reaction of bromoalkylamine. Either N-1-Boc-3-bromopropylamine (17) or N-(8-bromooctyl)phthalimide (19) reacted with methyl 3,5,6-tri-O-benzyl-alpha-beta-d-glucofuranoside (4) (C-2 position) and 1,2:3,5-(O-methylene)-alpha-d-glucose (11) (C-6 position), respectively, in the presence of sodium hydride in DMF at room temperature, affording the desired intermediates. For aminopropyl derivatives, yields varied between 57% and 65%, and for aminooctyl derivatives, yields varied between 40% and 71%. After deprotection of the amine functionality, the metal chelate was built up by dialkylation (6a-c and 13a,b) with methyl bromoacetate in the presence of triethylamine under reflux in THF. Yields varied between 56% and 69% for the glucose modified at the C-2 position and between 58% and 62% for the one modified at the C-6 position. All compounds were characterized by 1H or 13C NMR or both, IR, and mass spectroscopy. Final products were isolated as a mixture of alpha and beta anomers.

Enhanced cooperative binding of oligonucleotides to form DNA duplexes mediated by metal ion chelation.

Metal chelating iminodiacetic acid moieties were appended to abutting ends of two 9-mer oligonucleotides designed to hybridize contiguously on an 18-mer target. Chelation of 1 equivalent of Gd3+ cooperatively increases affinities of the oligonucleotides to the single stranded DNA target as evidenced by a 15 degrees C increase in Tm of the complex.

Steps toward High Specific Activity Labeling of Biomolecules for Therapeutic Application: Preparation of Precursor [188Re(H2O)3(CO)3]+ and Synthesis of Tailor-Made Bifunctional Ligand Systems

Two kit preparations of the organometallic precursor [(188)Re(H(2)O)(3)(CO)(3)](+) in aqueous media are presented. Method A uses gaseous carbon monoxide and amine borane (BH(3).NH(3)) as the reducing agent. In method B CO(g) is replaced by K(2)[H(3)BCO(2)] that releases carbon monoxide during hydrolysis. Both procedures afford the desired precursor in yields >85% after 10 min at 60 degrees C. HPLC and TLC analyses revealed 7 +/- 3% of unreacted (188)ReO(4)(-) and <5% of colloidal (188)ReO(2). Solutions of up to 14 GBq/mL Re-188 have been successfully carbonylated with these two methods. The syntheses of two tailor-made bifunctional ligand systems for the precursor [(188)Re(H(2)O)(3)(CO)(3)](+) are presented. The tridentate chelates consist of a bis[imidazol-2-yl]methylamine or an iminodiacetic acid moiety, respectively. Both types of ligand systems have been prepared with alkyl spacers of different length and a pendent primary amino or carboxylic acid functionality, enabling the amidic linkage to biomolecules. The tridentate coordination of the ligands to the rhenium-tricarbonyl core could be elucidated on the macroscopic level by X-ray structure analyses and 1D and 2D NMR experiments of two representative model complexes. On the nca level, the ligands allow labeling yields >95% with [(188)Re(H(2)O)(3)(CO)(3)](+) under mild reaction conditions (PBS buffer, 60 degrees C, 60 min) at ligand concentrations between 5 x 10(-4) M and 5 x 10(-5) M. Thus, specific activities of 22-220 GBq pe micromol of ligand could be achieved. Incubation of the corresponding Re-188 complexes in human serum at 37 degrees C revealed stabilities between 80 +/- 4% and 45 +/- 10% at 24 h, respectively, and 63 +/- 3% and 34 +/- 3% at 48 h postincubation in human serum depending on the chelating system. Decomposition product was mainly (188)ReO(4)(-). The routine kit-preparation of the precursor [(188)Re(H(2)O)(3)(CO)(3)](+) in combination with tailor-made ligand systems enables the organometallic labeling of biomolecules with unprecedented high specific activities.

Strategies for producing cluster-based magnetic arrays

Chelating ligands based on the iminodiacetic acid moiety can be used to control the solvolysis reactions of paramagnetic transition metal ions and allow various cluster-based magnetic materials to be isolated and characterised. This paper discusses the strategies that can be used to favour certain types of supramolecular interaction with the ultimate goal of engineering arrays of ‘single molecule magnets’. Ten different systems, which have been crystallographically characterised, are presented to illustrate the approach.

Single- or Dual-Mode Switching of Semisynthetic Ribonuclease S′ with an Iminodiacetic Acid Moiety in Response to the Copper(II) Concentration

Single- or Dual-Mode Switching of Semisynthetic Ribonuclease S′ with an Iminodiacetic Acid Moiety in Response to the Copper(II) Concentration

Single- or Dual-Mode Switching of Semisynthetic Ribonuclease S′ with an Iminodiacetic Acid Moiety in Response to the Copper(II) Concentration

Ribonuclease S′ bearing iminodiacetic acid as a metal-bindingsite was designed and semisynthesized by self-assembly of native S-protein with chemically modified S-peptide. Rationally designed incorporation of unnatural iminodiacetic acid groups as transition metal receptors can confer the dual mode of response to a metal cation (stabilization/destabilization, and thus activation/deactivation) with regard to the structure and activity of an enzyme (see diagram).

Design and Synthesis of a Transition Metal Responsive Semisynthetic Myoglobin-Bearing Iminodiacetic Acid Moiety

Iminodiacetic acid appended myoglobins (IDAn-Mb, n = 1, 2) were synthesized by conventional reconstitution of chemically modified hemes with apomyoglobin. The metal responsive property of the obtained IDAn-Mb was studied by metal ion titration, pH titration, circular dichroism (CD) and 1H NMR spectroscopies, and reduction with ascorbate. IDAn-Mb quantitatively bound various transition metal cations (Co2+, Ni2+, Zn2+, Cd2+, and Cu2+) but not Mg2+. The binding stoichiometry of IDA2-Mb was 1:1 for Co2+, Ni2+, Zn2+, and Cd2+ and 1:2 for Cu2+, whereas the stoichiometry of 1:1 was shown for IDA1-Mb to all transition metals (Co2+, Ni2+, Zn2+, Cd2+, and Cu2+). The acidic pKa shift of the H2O coordinated to the heme iron(III) was clearly observed upon the binding of transition metals, suggesting the microenvironmental change of the heme crevice. This was supported by the CD and 1H NMR spectra of IDAn-Mb. The transition metal induced structural changes of IDAn-Mb were reflected in their redox behavior, i.e., the re...

Palladium cluster catalysts supported on chelate resin-metal complexes

The dry beads of chelate resin-metal complexes have been prepared from metal ions and the chelate resin containing iminodiacetic acid moieties. The surface area of the chelate resin can be increased both by washing with an organic solvent miscible with water and by complexing with multi-valent cations. Palladium clusters are supported on the chelate resin-metal complexes by two methods, in which the order is reversed between “complexing of metal ions” and “supporting of palladium clusters”. The supported palladium clusters catalyze the hydrogenation of C=C bonds, and the catalytic activity greatly depends on the metal ions used for the complexation. In the case of typical metal ions, the complexing of metal ions after supporting of palladium clusters makes the surface area of the resin increase, but makes the catalytic activity decrease compared with the reverse order. In the case of lanthanoid ions, on the other hand, the same order makes both the surface area and the catalytic activity increase.

Platinum cluster catalysts supported on porous chelate resin-metal complexes: effect of resin porosity on catalytic activity

Porous chelate resin-metal complexes were prepared from a commercial chelate resin having iminodiacetic acid moieties. This was accomplished by complexing with multivalent cations such as Al{sup 3+} and drying after washing with ethanol. The supported platinum cluster catalysts, formed by reducing the platinum ions on the porous chelate resin-metal complexes, had a mean diameter of 26 {Angstrom}, occupying pores approximately 40 {Angstrom} in diameter of the chelate resin-metal complexes. These systems were then used as catalysts during the hydrogenation of olefin or diene. The catalytic activity was found to depend on the type of metal ion used in the chelate resin-metal complexes, and it increased in the order of Na{sup +} < Mg{sup 2+} < Al{sup 3+}. The surface area of the chelate resin-metal complex, measured by a BET method, also increased in the same order, suggesting that the surface area is related to the catalytic activity. 23 refs., 6 figs., 3 tabs.

Adsorption of nitrogen monoxide by the chelate resin-immobilized iron(II) complex and its application for simultaneous removal of nitrogen monoxide and sulfur dioxide

This paper reports on an aqueous dispersion of the resin-iron(II) complex prepared from FeSO{sub 4} and chelate resin containing iminodiacetic acid moieties. The dispersion can simultaneously adsorb nitrogen monoxide and sulfur dioxide from a dilute mixed gas used as a model of a flue gas. The adsorbent dispersion was slightly deactivated by oxygen. The rate of deactivation of the dispersion, however, was much less than that of an aqueous solution of the corresponding monomeric model due to the slow diffusion of oxygen into the resin in the former case. Even after deactivation, the chelate resin can be easily recovered from the deactivated aqueous dispersions by separation by filtration, washing with a hydrochloric acid solution, and neutralization with a sodium hydroxide solution. The recovered resin can be reused as a starting material for the preparation of the fresh adsorbent dispersion by mixing with an aqueous FeSO{sub 4} solution.

ChemInform Abstract: Removal of Nitrogen Monoxide by Dry Iron(II) Complex Immobilized on Chelate Resin. Preparation and Characterization of the Complex.

AbstractA novel dry‐type adsorbent of NO can be successfully prepared from an Fe(II) salt and a chelate resin (CR) containing iminodiacetic acid moieties.

The Removal of Nitrogen Monoxide by the Dry Iron(II) Complex Immobilized on Chelate Resin. The Preparation and Characterization of the Complex

Abstract A new dry-type adsorbent for nitrogen monoxide was successfully prepared from an iron(II) salt and a chelate resin containing iminodiacetic acid moieties. The capability of adsorbing nitrogen monoxide depended greatly on the method of preparation. The very active adsorbent was prepared by mixing 31.4 mmol of iron(II) sulfate and a commercial chelate resin containing 21.0 mmol of iminodiacetic acid moieties; the mixture was dried after the solid parts had been washed with methanol. The resulting solid adsorbent could adsorb more than 99% of the nitrogen monoxide from 6 dm3 of nitrogen gas containing 1000 ppm of nitrogen monoxide within 25 min. This high capability for adsorbing nitrogen monoxide was derived from the increase in the surface area (43.1 m2 g−1) of the resin-immobilized iron(II) complex upon washing with methanol. The mechanism for the increase in the surface area is also discussed.

The Adsorption and Desorption of Nitrogen Oxide by the Aqueous Dispersion of the Chelate Resin-Immobilized Iron(II) Complex

Abstract Aqueous dispersions of the chelate resin–iron(II) complex were prepared by ion-exchange in water from iron(II) sulfate and a chelate resin containing iminodiacetic acid moieties. The resulting dispersions in water (50 cm3) can adsorb 78% of the nitrogen oxide (NO) from 6 dm3 of nitrogen gas containing 1000 ppm of nitrogen oxide at 25 °C. The adsorption rate of NO by the dispersions depends greatly on both the particle size of the chelate resin used and the concentration of iron(II) in the supernatant. A fast adsorption of nitrogen oxide can be achieved by using small particles of the chelate resin and by dissolving a large amount of iron(II) ions in the aqueous part of the dispersions. The adsorption and desorption of nitrogen oxide can be understood in terms of a 1:1 reversible coordination of NO to the iron(II) ion immobilized on the chelate resin. The equilibrium constant, enthalpy change, and entropy change for the above adsorbing reaction were 3.11×104 dm3 mol−1, −45.6 kJ mol−1, and −68.2 J K−1 mol−1 respectively. Since the adsorbing reaction of NO in this system is reversible, the adsorbed NO can be released by heating the dispersions which have already adsorbed NO. The amount of the released NO can be predicted from the equilibrium constant at the releasing temperature. Moreover, a concentrated recovery of the NO can be achieved by the present aqueous dispersions system.

N-pyridoxylidenehydrazine-N',N'-diacetic acid. III. Formation of metal chelates in solution.

Metal chelate formation of N-pyridoxylidenehydrazine-N ', N '-diacetic acid (1) and related hydrazines in solution was studied by means of absorption spectroscopy. Compound 1 and N-pyridoxylidene-N'-methylhydrazine (2) in methanol formed Cu (II) chelates of the same spectral character, which indicated the chelation of the phenolate oxygen and the hydrazine nitrogen atoms to Cu (II). The compositions of the chelates were 1 : 1 for 1 and 1 : 2 for 2, indicating that 1 acts as a tri- or tetradentate ligand. N- (3-Hydroxy-4-pyridylmethylene) hydrazine-N', N'-diacetic acid formed a Cu (II) chelate similar to that of 1 but N-pyridoxylidene-N', N'-dimethylhydrazine and N-pyridoxylidene-N', N'-diphenylhydrazine did not form chelates under similar conditions. Addition of an equimolar or excess amount of Co (II), Ni (II), Zn (II), Cd (II) or La (III) salt to 1 in methanol gave rise to absorption assignable to the chelate of 1, whereas 2 did not form metal chelates under the same conditions. It was concluded that the iminodiacetic acid moiety of 1 coordinated to the metal ions and enhanced the stability constant of the metal chelates.

CHELATE RESIN-IMMOBILIZED IRON(II) COMPLEXES AS NEW NITROGEN OXIDE ADSORBENTS

Abstract Iron(II) ions were immobilized on the chelate resin by treating crosslinked polystyrene beads involving iminodiacetic acid moieties with iron(II) sulfate in water. The resin-immobilized Fe(II) complexes, especially those prepared with fine beads, can adsorb nitrogen oxide rapidly in water from nitrogen atmosphere containing 1000 ppm nitrogen oxide.

Selective Hydrogenation of Cyclopentadiene to Cyclopentene Using Colloidal Palladium Supported on Chelate Resin

Abstract Cyclopentadiene was hydrogenated to cyclopentene selectively by using colloidal palladium supported on chelate resin with iminodiacetic acid moieties as a catalyst. The catalyst, containing metal particles of 1–6 nm in diameter, was prepared by reduction of the palladium(II)–chelate resin complex with methanol. Cyclopentene was produced in 97.1% yield at 100% conversion of cyclopentadiene at 30 °C under 1 atm of hydrogen. This value in yield was also achieved on repeated uses of the catalyst. The hydrogenation rate was correlated to the polarity parameter, ET(30) values, of the solvents used in the reaction, except in the case of dimethyl sulfoxide. The hydrogenation rates of cyclopentadiene (RD) and cyclopentene (RE) were expressed as RD=kD[H2][catalyst] and RE=kE[H2][cyclopentene][catalyst], respectively, where kD and kE are the rate constants. The equilibrium constant for complex formation between cyclopentadiene and the catalyst, KD, was estimated to be over 400 times larger than that between cyclopentene and the catalyst, KE. A mechanism, including the coordination of olefins to the catalyst and the subsequent hydrogenation of the coordinated complexes, was proposed.