Sorption behavior of iminodiacetic acid resin for indium

In（Ⅲ） was quantitatively adsorbed by iminodiacetic acid resin （IDAAR） in the medium of pH = 4.52. The statically saturated sorption capacity of IDAAR is 235.5 mg·g^-1. 1.0 mol·L^-1 HCl can be used as an eluant. The elution efficiency is 97.9%. The resin can be regenerated and reused without apparent decrease of sorption capacity. The sorption rate constant is k298 = 1.94 × 10-5 s^-1. The apparent sorption activation energy of IDAAR for In（Ⅲ） is 20.1 kJ·mol^-1. The sorption behavior of IDAAR for In（HI） obeys the Freundlich isotherm. The enthalpy change is AH= 17.2 kJ·mol^-1.

Adsorption of Iminodiacetic Acid Resin for Lutetium

The adsorption behavior and mechanism of a novel chelate resin, iminodiacetic acid resin (IDAAR) for Lu(Ⅲ) were investigated. The statically saturated adsorption capacity is 210.8 mg·g^(-1) at 298 K in HAc-NaAc medium. The Lu(Ⅲ) adsorbed on IDAAR can be eluted by 0.5 mol·L^(-1) HCl and the elution percentage reaches 96.5%. The resin can be regenerated and reused without obvious decrease in adsorption capacity. The apparent adsorption rate constant is k_(298)=2.0×10^(-5) s^(-1). The adsorption behavior of IDAAR for Lu(Ⅲ) obeys the Freundlich isotherm. The thermodynamic adsorption parameters, enthalpy change ΔH, free energy change ΔG and entropy change ΔS of IDAAR for Lu(Ⅲ) are 13.1 kJ·mol^(-1), -1.37 kJ·mol^(-1) and 48.4 J·mol^(-1)·K^(-1), respectively. The apparent activation energy is E_a=31.3 kJ·mol^(-1). The molar coordination ratio of the functional group of IDAAR to Lu(Ⅲ) is about 3∶1. The adsorption mechanism of IDAAR for Lu(Ⅲ) was examined by chemical method and IR spectrometry.

Synthesis and Crystal Structure of a Two-dimensional Silver Framework Constructed by H_2idc (H_2idc = Iminodiacetic Acid)

A new compound formulated [Ag2(idc)](NO3)?H2O (H2idc = iminodiacetic acid) was synthesized under mild conditions and characterized by IR spectrum and single-crystal X-ray diffraction. The crystal crystallizes in the monoclinic system, space group of P21/n with a = 5.5029(2), b = 11.1316(5), c = 15.5319 (1) ?, β = 96.038(3)o, V = 946.15(6) ?3, Z = 4, R = 0.0619 and wR = 0.1606. Its structure is a 2D polymer, whose repeat units consist of dinuclear silver cluster coordinated by two bridging iminodiacetic acids. In the complex, the Ag(I) ions adopt three coordinate fashions, and the Ag-Ag metal-metal contacts of 2.8418 ? are observed.

Study on Inspection of Synthetic Reaction for Preparation of N-(phosphonomethyl) iminodiacetic Acid with Iminodiacetic Acid by Precolumn Derivatization-HPLC

The derivatives of the reaction liquid for synthesizing N-（phosphonomethyl） iminodiacetic acid （PMIDA） were synthesized with 9-fluorenyl methyl chlomformate （FMOC-C1） as the derivatization reagent. The separation of the derivatives was performed on a Gemini C18 column at room temperature by isocratic elution. The mobile phase was composed of 60% 0.05 M Nail2 PO4 （pH = 3.5） and 40% CH3 CN at a flow rate of 1 ml/min. The injection volume was 10 td, and the detection wavelength was 265 nm. The linear ranges of the derivatives of iminodiacetonitrile, iminodiacetic acid （IDA） and ammonia were, respectively, 0.02-1.2, 0.02-1.2 and 0.1 -2. 0 mg/ml with correlation coefficients not smaller than 0. 999 8. The detection limits for the derivatives were, respectively, 0. 000 4, 0. 000 4 and 0.003 mg/ml. The average recoveries of 3 derivatives were respectively 99.96%, 99. 86% and 99.89%, respectively, with relative standard deviation values not smaller than 1.6%. The method developed in the present paper could be used for monitoring the reaction system for preparation of PMIDA by IDA.

Determination of iminodiacetic acid in the glyphosate by ion chromatography

In this paper,a simple method based on ion chromatography（IC） with conductivity detection was developed for the determination of iminodiacetic acid（IDA） in the herbicide of glyphosate.Under optimized chromatographic conditions,good linear relationship,sensitivity and reproducibility were obtained.The detection limit（LOD） for IDA obtained by injecting 25 μL of sample was 31.8 μg/L（S/N = 3）.Relative standard deviation（RSD） of repeated analysis for the peak areas was less than 1.53%（n = 6）.A spiking study was performed with satisfactory recoveries between 92.8%and 103.6%.It was confirmed that this method could be applied in glyphosate products.

Study on the Complexation of Molybdenum（Ⅵ） with Iminodiacetic Acid and Ethylenediamine-N,N′-diacetic Acid by Specific Ion Interaction and Debye-Hückel Theories

Complexation of two ligands, iminodiacetic acid and ethylenediamine-N,N′-diacetic acid, with molybdenum（Ⅵ） was studied in aqueous solutions. Molybdenum（Ⅵ） forms a mononuclear complex with the aforementioned ligands of the type MoO3L^2-. All measurements have been carried out at 25 ℃ and different ionic strengths ranging from 0.1 to 1.0 mol·L^-1 of NaClO4, with the pH justified to 6.0. Equilibrium concentration products and stoichiometry of the complexes have been determined from a combination of potentiometric and UV spectroscopic measurements. Comparison of the ionic strength effect on these complex formation reactions has been made using a Debye-Hückel type equation and Bronsted-Guggenheim-Scatchard specific ion interaction theory （SIT）. Debye-Hückel theory predicted the first order effects on simple electrolyte solutions. Interactions between the reacting species and the ionic medium were taken into account in the SIT model. All of the calculations have been done by the computer program Excel 2000.

Investigation on the Use of the Weakly Basic Polyacrylate Anion-Exchanger Amberlite IRA-68 for Sorption and Separation of Iminodiacetate Complexes of Rare Earth Elements

Based on the determined affinity series of rare earth element complexes with IMDA for the anion-exchangers, purification of macroquantities of Nd 3+ from Y 3+, Sm 3+ from Ho 3+, La 3+ from Nd 3+ and La 3+ from Pr 3+ on the weakly basic gel anion-exchanger Amberlite IRA-68 was studied. Using the presented method on 1 L of Amberlite IRA-68 in the acetate form, it is possible to obtain about 240 g Nd 2O 3 purified from Y 2O 3. Great difference in affinity of La 3+ and Nd 3+ as well as Pr 3+ complexes for this anion-exchanger in the acetate form indicates the possibility of applying this process for purification of lanthanum on the increased scale. On 1 L of Amberilte IRA-68 in the acetate form it is possible to obtain about 1125 g La 2O 3 purified from Nd 2O 3. On the basis of these results it can be assumed that unique properties of polyacrylate anion-exchangers enable their application for separation of rare earth elements.

Synthesis of an Indium-iminodiacetate Two-dimensional Layer Network with Rhombus Grids

The title compound, [InCl（C4H5NO4）]n, has been synthesized via the hydrothermal method and characterized by IR, elemental analysis, UV-Vis-Nir spectra and single-crystal X-ray diffraction analysis. Single-crystal X-ray analyses show that it is a carboxylate-bridged two-dimensional layer network indium（III） polymer, catena-poly[[chloroindium（III）]-μ-（iminodiacetate к4N,O,O＇：O＇＇：O＇＇＇]. The crystal is of orthorhombic system, space group Pnma with a = 13.5970（13）, b = 8.7671（10）, c = 6.0427（5）, C4H5ClInNO4, Mr = 281.36, V = 720.33（12）3, Z = 4, Dc = 2.594 g/cm3, F（000） = 536, μ = 3.613 mm-1, R = 0.0245 and wR = 0.0570. The In（III） ion exhibits an approximately octahedral InClNO4 coordination environment, with the two O donor atoms of iminodiacetate and two O atoms belonging to the carboxylate group of two adjacent iminodiacetates occupying the basal positions, and the chlorine ion and one nitrogen atom of iminodiacetate in the apical sites. Carboxylate groups are mutually cis oriented, and each syn-anti carboxylate group bridges two indium（III） ions via two different basal positions, resulting in the formation of a 2-D network with rhombus （4, 4） grids. Each rhombus grid unit is formed from four indium atoms and four iminodiacetate units with the diagonal lengths of 8.767（1） and 6.043（1）.

Study on Separation of Lanthanum from Praseodymium Complexes with IMDA by Gel and Macroporous Anion Exchangers

During our studies on separation of rare earth complexes with aminopolycarboxylic acids on anion-exchangers, it is found that the affinity series of these elements with IMDA (Ln 3+ ∶IMDA=1∶2) for the anion-exchanger Dowex 1 in the acetate and IMDA forms is non-typical: Dy 3+ > Ho 3+ > Gd 3+ >Eu 3+ >Er 3+ >Y 3+ >Sm 3+ >Tm 3+ >Nd 3+ >Pr 3+ >>La 3+ . In the affinity series La 3+ is characterised as the lowest affinity in comparison with other rare earth elements, which indicates possibility of purification of La 3+ from all remaining lanthanides as well as Pr 3+ in the macro-micro systems by the frontal analysis technique. In the investigations strongly basic gel anion-exchangers Dowex 1×8 (type 1) and Dowex 2×8 (type 2) and strongly basic and weakly basic macroporous anion-exchangers Dowex MSA-1 and Dowex MWA 1 were used. Macroporous ion-exchangers have a sponge-like matrix which contains pores larger than molecules in size and the exchange of large ions is faster. The studies indicate that both the gel and macroporous anion-exchangers are useful for purification of La 3+ from Pr 3+ complexes with iminodiacetic acid.

A New Route for the Synthesis of N-Substituted Diketopiperazine Derivatives

Eight N-substituted diketopiperazines （DKPs） were synthesized by solid-phase protocols. The introduction of iminodiacetic acid （Ida） and followed another a-amino acid residue as the precursor of DKP framework made the present synthesis to be very facile and efficient.

Synthesis and Crystal Structure of a New Praseodymium（Ⅲ）-Copper（Ⅱ） Polymeric Complex:〔Pr2Cu3（L1）6〕n（H2L1=NH｛CH2COOH｝2）

A novel polymeric Pr 2Cu 3 complex of iminodiacetic acid (H 2L 1=NH{CH 2COOH} 2) Pr 2Cu 3(L 1) 6 n , 1, has been synthesized and structurally characterized. The title complex Pr 2Cu 3O 24 N 6C 24 H 30 ( M r =1258.97) crystallized in trigonal space group P3 c1 (No. 165) with a = 13.424(4), c=14.752(6); V=2303(1) 3; F(000)=1226; λ (Mo Kα )=35.2 cm -1 ; D c =1.820 g·cm -3 ; Z =2. The final R and R w are 0.072 and 0.081 respectively for 1412 reflections with I】3σ(I) . In crystal 1, the Pr 3+ ion is nine coordinated by 6 O atoms from three bidentate chelating carboxylate groups and 3 O atoms from three anti anti bridging carboxylic groups of six L 1 ligands; the Cu 2+ ion is six coordinated by 4 O and 2 N atoms from two pentadentate L 1 ligands. Each pair of Pr(Ⅲ) atoms is bridged by three L 1 ligands, each of which also chelates with one copper(Ⅱ) ion, thus forming a Pr 2Cu 3 cluster unit. Such cluster units are cross linked by flexible L 1 ligands into a three dimensional coordination framework.

Synthesis of Highly Stable Porous Metal-lminodiacetic Acid Gels from a Novel IDA Compound

In this work, a novel and simple flexible aromatic multi-carboxylate compound N,N＇（4,4＇-biphenylyl） iminodi- acetic acid （BP-IDA） was synthesized, with which two new stable metaMDA gels （denoted as MIGl and MlG2） with three-dimensional network structures have been prepared successfully by employing Cr^3＋ and Al^3＋ as the metal ions, respectively. The rheological performance was investigated by means of dynamic rheology measurement. The morphology and microstructure were characterized by scanning electron microscopy, transmission elec- tron microscopy, and X-ray diffraction technique. Nitrogen sorption isotherm measurement suggests that the MlG1 aerogel has considerable porosity with the Brunauer-Emmett-Teller specific surface area up to 760 m^2·g^-1. Owing to easy preparation, good stability, and three-dimensional network structure, the as-prepared metal-organic gels will possess potential applications in separation, catalysis, and drug delivery.