Extraction of Uranium(VI) and Thorium(IV) from Nitric Acid Solution by N,N,N′,N′ – Tetraoctylglutaricamide

Synthesis and characterization of N,N,N′,N′-tetraoctylglutaricamide (TOGA) was carried out and used for extraction of U(VI) and Th(IV) from nitric acid solutions. The processes of extraction were determined by the slope analysis and by analyzing a function that allows the simultaneous treatment of all the experimental points obtained in different conditions. The different factors affecting the extraction distribution ratio(D) of U(VI) and Th(IV) (extraction concentration, concentrations of nitric acid, salting-out agent NaNO₃ concentration, equilibration time, temperature, and types of diluents) were investigated. The results obtained indicated that the extraction species of U(VI) and Th(IV) are mainly extracted as UO₂(NO₃)₂·1.0TOGA and Th(NO₃)₄·1.5TOGA. The apparent equilibrium constant of U(VI) and Th(IV) extraction determined are 3.35 ± 0.03 L³/mol³ and 1.87 ± 0.01 L⁵/mol⁵ at 298 ± 1 K. Thermodynamic parameters such as the free energy(ΔG), enthalpy(ΔH), and entropy(ΔS) changes associated with the extraction processes could be evaluated. Back-extraction of U(VI) and Th(IV) from organic phases was also studied.     

Synthesis and properties of polysiloxane containing N,N′-bis(diphenylsilyl)tetraphenylcyclodisilazane

A new kind of polysiloxane containing N,N′-bis(diphenylsilyl)tetraphenylcyclodisilazane was prepared by the anionic polymerization with a “seed solution” as initiator. The synthesis of monomers N,N′-bis(hydroxydiphenylsilyl)tetraphenylcyclodisilazane (BHPTPC), N,N′-bis(chlorodiphenylsilyl)tetraphenylcyclodisilazane (BCPTPC), and 1,3-dichloro-1,1,3,3-tetraphenyldisilazane (DCTPS) are all reported in this study. The synthesized polysiloxane containing N,N′-bis(diphenylsilyl)tetraphenylcyclodisilazane was characterized by ¹H–NMR, ²⁹Si–NMR, gel permeation chromatography (GPC), and intrinsic viscosity. The thermal stability of the polysiloxane was studied by isothermal gravimetric analysis (IGA). The results demonstrated that the synthesized polysiloxane containing N,N′-bis(diphenylsilyl)tetraphenylcyclodisilazane had excellent thermal stability. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 929–933, 2001     

Synthesis and Thermal Decomposition Studies of Silicon (IV) Compounds with N,N’-Bis(Salicylidene)Ethylenediimine

The silicon (IV) compounds possessing SiN₄O₂ (6), SiN₂O₂C₂ (7, 8), SiN₂O₂CCl (9) and SiN₄O₄ (10) coordinating frameworks have been synthesized in high yield by the reaction of the O,N,N,O- donor salen-type ligand N,N’-bis(salicylidene)ethylenediimine L with different silanes i.e. diethoxydiisocyanatosilane-(C₂H₅O)₂Si(NCO)₂ 1, dichlorodiphenylsilane-Ph₂SiCl₂ 2, dichloromethyl- phenylsilane-MePhSiCl₂ 3, trichlorophenylsilane-PhSiCl₃ 4 and silicon tetrachloride-SiCl₄ 5. The compounds 6–10 have been characterized by elemental analysis, IR, ¹H, ¹³C and ²⁹Si NMR and mass spectrometry. The decomposition reactivity of these compounds has been studied using a Thermal Gravimetric Analyzer (TGA) at a heating rate of 10°C/minute in an inert atmosphere.     

Evaluation of the Hydrophilic Complexant N,N,N’,N’-tetraethyldiglycolamide (TEDGA) and its Methyl-substituted Analogues in the Selective Am(III) Separation

ABSTRACT

N,N,N’,N’-tetraethyldiglycolamide (TEDGA) is used in the French EXAm (extraction of americium) process to separate Am(III) from Cm(III) and Ln(III). In this study, the complexation behavior of TEDGA towards actinides(III) and lanthanides(III) was compared to its methyl-substituted derivatives Me-TEDGA and Me₂-TEDGA under experimental conditions applying to the EXAm process. Using the EXAm solvent, 0.6 mol/L N,N’-dimethyl-N,N’-dioctyl-hexylethoxymalonamide (DMDOHEMA) and 0.45 mol/L bis(2-ethylhexyl)-phosphoric acid (HDEHP), An(III) and Ln(III) distribution ratios increase in the order TEDGA < Me-TEDGA < Me₂-TEDGA. This is explained by differences in the strength of complexation in the aqueous phase: Conditional stability constants for the formation of [Cm(DGA)_x]³⁺ complexes decrease in the order TEDGA > Me-TEDGA > Me₂-TEDGA, as shown by time-resolved laser fluorescence spectroscopy (TRLFS). TRLFS measurements verified the exclusive existence of [Cm(DGA)₃]³⁺ complexes in the aqueous phase. Both the homoleptic [Cm(DMDOHEMA)_n]³⁺ and the heteroleptic [Cm(DGA)_x(DMDOHEMA)_y]³⁺ complexes were detected in the organic phase, as postulated in the literature.^[14]     

Extraction of Copper(II) with N′,N′-Dialkylhydrazides of Benzoic and Phenylacetic Acids

This article is concerned with the study of the extraction of Cu(II), Co(II), Ni(II), and Zn(II) with N′,N′-dialkylhydrazides of benzoic and phenylacetic acids. The applied reagents are able to extract Cu(II) from ammoniac media efficiently. The influence of the length and structure of alkyl chains on the extraction of Cu(II) has been analyzed. It is shown that N′,N′-dibytil- and N′,N′-dihexylhydrazides of benzoic acid exhibit the most promise for extracting Cu(II) from ammoniac media, and N′,N′-dihexylhydrazide of phenylacetic acid as an extractant is worse than the analogous benzoic acid derivative. Copper stripping has been studied for various concentrations of H₂SO₄, and the copper extraction constants have been calculated. The data obtained indicate that the degree of Cu(II) extraction decreases with increasing concentration of ammonium salts.     

Synthesis and Structure of 1D Copper(II) Polymers with Dissymmetrical N,N′-Bis(substituted)oxamide Ligands: Cytotoxicity and DNA-Binding Property

Two one-dimensional copper(II) coordination polymers with different dissymmetrical N,N′-bis(substituted)oxamide ligands were synthesized, namely {[Cu₂(dmaepox)(dabt)]pic·H₂O}_n (1) and {[Cu₂(dmapob)(dabt)]NO₃·0.6H₂O}_n (2), where H₃dmaepox and H₃dmapob stand for N-(2-carboxylatophenyl)-N′-[3-(methylamino)propyl]oxamidate and N-(2-carboxylatophenyl)-N′-[3-(dimethylamino)propyl]oxamidate, respectively, and dabt is 2?2′-diamino-4?4′-bithiazole. Polymer 1 was characterized by elemental analyses, IR and electronic spectra and single-crystal X-ray diffraction. The crystal structure reveals that polymer 1 consists of many binuclear copper(II) units bridged by cis-oxamide and carboxylate groups. The two copper(II) ions are located in square-planar and square-pyramidal coordination environments, respectively. The separations of the Cu(II) atoms bridged by oxamide and carboxylate groups are 5.2035(7) and 5.1196(7) Å, respectively. The crystal structure of polymer 2 has been reported in our previous paper. However, its relative properties were not studied. In order to compare the influence of different bridging ligands on the cytotoxicities and DNA-binding properties, the cytotoxicities and reactivities towards DNA of polymers 1 and 2 were investigated. The results suggest that the two polymers can interact with herring sperm DNA in the mode of intercalation with binding affinities following the order of 1 > 2, and this is consistent with their in vitro cytotoxicities.     

N,N,N′,N′-Tetra(2-Ethylhexyl) Thiodiglycolamide T(2EH)TDGA: A Promising Ligand for Separation and Recovery of Palladium from High Level Liquid Waste (HLLW) Solutions

The extraction properties of N,N,N′,N′-tetra(2-ethylhexyl)thiodiglycolamide T(2EH)TDGA have been evaluated for the separation and recovery of palladium from simulated high-level liquid waste (SHLW). T(2EH)TDGA has shown very high selectivity for Pd (II) over other metal ions present in SHLW. The separation factor (SF) for Pd (II) over other metal ions was found to be more than 10⁵. Reusability studies of the extractant indicate that D_Pd remained almost constant even after five successive cycles of extraction and stripping. Palladium was quantitatively recovered from thiourea strip solution by treating it with ammonia and filtering the precipitate of palladium sulphide. The acid uptake constant (K_H) was found to be 0.62 which could be due to the presence of two carbonyl groups of amidic moiety. To account for very high extractability of palladium with T(2EH)TDGA over other ‘S’ donor extractants, namely Bis-(2-ethylhexyl)sulphoxide (BESO), FTIR, as well as Raman studies were carried out. FTIR and Raman studies suggested the ligation through carbonyl as well as the thio-ether group. Conditional extraction constants (log K′_ex) were determined and the thermodynamic parameters were calculated from the dependence of the conditional extraction constant (log K′_ex) on temperature. The calculated values of ΔG_ex, ΔH_ex, and ΔS_ex were ?41.78 kJmol^?1, ?55.12 kJmol^?1 and ?44.04 JK^?1 mol^?1 respectively. The extraction process is indicated to be enthalpy driven with the entropy factor counteracting it.     

Synthesis,characterization, thermal constant and relaxation of gadolinium(III), iron(III) and manganese(II) chelates of diethylenetriamine-bis-inositol-N,N′,N″-triacetic acid

The reaction of the bicyclic anhydride of diethylenetraiamine-pentaacetic acid (DTPAA) with inositol gave diethylenetriamine-inositol-biester-N,N^′,N″-triacetic acid (DTPA-BI) (1). (1) was characterized by FAB-MS, ¹HNMR, IR and elemental analysis. Its chelates of Gd(III), Fe(III) and Mn(II) holding promise of magnetic resonance imaging (MRI) were synthesized. Gd(III) complex was obtained from Gd₂O₃ and the acid form of (1). Thermodynamic stability constant and relaxation of Gd(III) complex with DTPA-BI were determined. The spin–lattice relaxivity (R₁=5.6 l mmol⁻¹ s⁻¹) of chelate was slightly larger than that of [GdDTPA]²⁻. The results showed that the complex is a prospective MRI agent, although thermodynamic stability constant of DTPA-BI K_[GdDTPA-BI]⁻=10^18.2 was a little less than that of [GdDTPA]²⁻ (K_[GdDTPA]²⁻=10^20.73).     

Synthesis and Properties of Novel Soluble and Thermally Stable Optically Active Poly(amide-imide)s from N,N’-(4,4’-Oxydiphthaloyl)-bis-L-phenylalanine Diacid Chloride and Aromatic Diamines

Summary In this research work, 4,4-oxydiphthalic anhydride (1) was reacted with L-phenylalanine (2) in acetic acid and the resulting imide-acid 3 was obtained in high yield. This imide-acid 3 was converted to diacid chloride 4 by reaction with thionyl chloride. The polycondensation reaction of diacid chloride 4 with several aromatic diamines such as 4,4-sulfonyldianiline (5a), 4,4-diaminodiphenyl methane (5b), 4,4-diaminodiphenylether (5c), p-phenylenediamine (5d), m-phenylenediamine (5e), and 4,4-diaminobiphenyl (5f) was performed by two conventional methods: low temperature solution polycondensation and short period reflux conditions. Several new thermally stable optically active poly(amide-imide)s with inherent viscosity ranging from 0.34–0.62 dL/g were obtained with high yield. All of the above polymers were fully characterized by ¹H-NMR, FT-IR, elemental analyses and specific rotation techniques. Some structural characterizations and physical properties of this new optically active poly (amide-imide)s are reported.     

Manufacture and Characterization of Biodegradable Nanocomposites Based on Nanoscale MgAl-Layered Double Hydroxide Modified with N,N′-(Pyromellitoyl)-bis-L-Isoleucine Diacid and Poly(vinyl alcohol)

Bionanocomposite films of poly(vinyl alcohol) (PVA) with Mg-Al LDHs were prepared with different compositions by solution-intercalation method. N,N′-(Pyromellitoyl)-bis-L-isoleucine diacid was synthesized and it was used for organo-modification of chiral MgAl-LDH in distilled water. Hybrid films of PVA and modified chiral LDH were prepared under ultrasonic irradiation technique. The effect of LDH contents on thermal, physicomechanical, and morphological properties of PVA films were investigated by using X-ray diffraction, Fourier transform infrared, thermogravimetric analysis, field emission scanning electron microscopy and transmission electron microscopy techniques. Mechanical data indicated improvement in the tensile strength and modulus with increasing of the LDH loading until 4%.     

N,N′-乙撑双(硬脂酰胺)

分了C:7H。。一e一NH一CH:CH:一NH一C一Ci:Ha。 C:.H,eN,O: 分子量593 l英文名IN,N‘一Ethylene bis(s-tearanl记e) l国外商品名1 Chemetronwa、一100(Chemetron);Armowax EBS(Armak)书H佣ehst WaxC(Hoechst);AerawaxC(Glyeo),Kemam溉w 20(枷mko);Lubro/EA(ICI)。 l性状】白色至淡黄色粉末或粒状物。熔点130一145℃,闪点约285℃,比重0.98。不溶于水,常温下不溶于乙醇、丙酮等大多数溶剂,可溶于混合二甲苯、菇烯、丁醇、甲基溶纤素及大多数氯代烃类。游离脂肪酸含量低于4%,水份低于。.5%。 【制法】乙撑双硬脂酞胺的制备是…     

Studies on the Use of N,N,N´,N´-Tetra(2-ethylhexyl) Diglycolamide (TEHDGA) for Actinide Partitioning. I: Investigation on Third-Phase Formation and Extraction Behavior

Abstract

Diglycolamides have emerged as an interesting class of extractants for actinide partitioning from high-level waste (HLW). N,N,N´,N´-tetraoctyl diglycolamide (TODGA) has been extensively studied for lanthanide-actinide co-extraction behavior. The present work deals with a branched isomer of TODGA, that is, N,N,N´,N´-tetra(2-ethylhexyl) diglycolamide (TEHDGA). TEHDGA was studied for the extraction of ²⁴¹Am and third-phase formation. The effect of using different phase modifiers on the prevention of the formation of a third phase during nitric acid extraction by TEHDGA along with the acid uptake behavior by TEHDGA in the presence of the modifiers was studied. The modifiers used for this purpose were di(n-hexyl)octanamide (DHOA), isodecanol, and n-decanol. The effect of the modifiers on the uptake of ²⁴¹Am as a function of acid concentration and as a function of modifier concentration was also examined. DHOA was found to be a suitable modifier, in spite of its high acid uptake. The uptake of lanthanides Ce, La, Eu, Gd, and Nd and elements such as Fe, Ni, Mn, Mo, Ru, Sr, and Cs with DHOA-modified TEHDGA–n-dodecane solvent systems were investigated. The results obtained indicated that, while DHOA-modified TEHDGA/n-dodecane extracted lanthanides and actinides, it did not show any significant uptake of other elements. Thus, the TEHDGA-DHOA/n-dodecane solvent system can be used effectively for the partitioning of lanthanides and actinides from HLW.     

Extraction Behavior of Actinides and Metal Ions by the Promising Extractant,N,N,N′,N′-Tetraoctyl-3,6-dioxaoctanediamide (DOODA)

Abstract

The extraction of actinides, fission products, some non-nuclear elements, and nitric acid by N,N,N′,N′-tetraoctyl-3,6-dioxaoctanediamide (DOODA-C₈) in dodecane was extensively studied. Also studied was the extraction of HNO₃ and Nd(III) by the tetradodecyl analog of DOODA-C₈ in dodecane. Both extractants contain two ether oxygen atoms in the backbone chain carrying the two amide groups and can thus act as tetradentate ligands. The extractability of actinides decreases in the order Pu(IV) > U(VI), Am(III) > Np(V) in the extraction from nitric acid and Pu(IV) > Am(III) >> U(VI) in the extraction from perchloric acid. Ions of di-, tri-, tetra-, hexa-, and heptavalent metals strongly differ in the extractability by DOODA-C₈ but, except for lanthanides(III), there is no visible correlation of their distribution ratios with ionic radii. Due to the efficient extraction of actinides, weak extraction of fission products, and sufficient extraction capacity, DOODA-C₈ is a promising extractant for the recovery of minor actinides from high-level radioactive wastes.     

2,2′‐(Methylimino)bis(N,N‐dioctylacetamide) (MIDOA), A New Tridentate Extractant for Technetium(VII), Rhenium(VII), Palladium(II), and Plutonium(IV)

2,2′‐(Methylimino)bis(N,N‐dioctylacetamide) (MIDOA) was developed as a new extractant for technetium. MIDOA has a similar backbone to TODGA, N,N,N′,N′‐tetraoctyldiglycolamide, where the nitrogen atom bearing a methyl group replaces the ether oxygen in TODGA. MIDOA is highly lipophilic and ready to use in the HNO₃–n‐dodecane extraction system. The distribution ratio (D) for Tc(VII) is extremely high. In addition, Cr(VI), Re(VII), Mo(VI), W(VI), Pd(II), and Pu(IV) are well extracted by MIDOA. MIDOA has high selectivity toward certain oxometallates. The D(Tc) values decrease gradually with HNO₃, H⁺, and NO₃ ^? concentrations, and the log D vs log [MIDOA] dependence indicates the species extracted to be the 1:1 metal‐ligand complex. It is clear that MIDDA [2,2′‐(methylimino)bis(N,N‐didodecylacetamide)] and IDDA [2,2′‐(imino)bis(N,N‐didodecylacetamide)], which have structures analogous to MIDOA, have similar extraction behavior to that of MIDOA.     

Research on curing mechanism and thermal property of bis-allyl benzoxazine and N,N′-(2,2,4-trimethylhexane-1,6-diyl) dimaleimide blend

A blend of 2,2′-bis(8-allyl-3-phenyl-3,4-dihydro-2H-1,3-benzoxazinyl) propane (Bz-allyl) and N,N′-(2,2,4-trimethylhexane-1,6-diyl) dimaleimide (TBMI) was prepared. The curing mechanism and thermal property of the cured blend were studied with Differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) and Dynamic mechanical analysis (DMA). It was found that in BzT11 the thermal polymerization reaction of TBMI, the reaction of TBMI catalyzed by Bz-allyl, Ene reaction between TBMI and allyl groups occurred at a low temperature (160 °C) simultaneously. About 20% of TBMI was consumed by Ene reaction. Besides, seldom oxzine ring of Bz-allyl polymerized at a low temperature (160 °C) and most oxzine ring of Bz-allyl reacted at a high temperature (over 160 °C). The T_g of cured blends was increased with the increment of the proportion of TBMI in the blends.     

Studies on the Separation and Recovery of Palladium from Simulated High Level Liquid Waste (SHLW) Solution with Novel Extractant N,N,N′,N′-tetra (2-ethylhexyl) Dithiodiglycolamide DTDGA

The extraction properties of N,N,N',N'-tetra-(2-ethylhexyl) dithiodiglycolamide (DTDGA) have been evaluated for separation and recovery of palladium from simulated high-level liquid waste (SHLW) solution. Extraction of Pd was found to increase with increase in nitric acid concentration up to 4.0 M, above which the extraction remains almost constant. Acid uptake studies show 1:1 stoichiometry between DTDGA and HNO₃ at nitric acid concentration above 3.0 M. The acid uptake constant (K_H) was found to be 0.60 which could be due to the presence of two carbonyl groups of amidic moiety. DTDGA has shown very high extractability and selectivity for Pd over other metal ions present in SHLW. The separation factor (SF) for Pd over other metal ions was found to be more than 10⁴. Almost complete back extraction of palladium from organic phase was achieved with 0.01 M thiourea in 0.1 M nitric acid. Reusability studies of the extractant indicate that D_Pd remains almost constant even after five successive cycles of extraction and stripping. Two extraction stages will be required for complete extraction of 100 mg/L Palladium in 3.0 M nitric acid solution using 0.0025 M DTDGA/n-dodecane solvent system.     

Determination of N,N’, N’’-tris(3,7-dimethyloctyl)guanidine (TiDG) in Cesium Extraction Solvent

Several analytical methods were evaluated for determining the concentration of N,N’,N”-tris(3,7-dimethyloctyl)guanidine (TiDG) in a cesium extraction solvent. Of the methods evaluated, non-aqueous titration and ¹H NMR were shown to be successful at quantifying the amount of TiDG present in both a pure solvent extraction system, and a blended system containing an additional base, trioctylamine.     

Three three-dimensional supramolecular networks formed by one-dimensional chains of Ag(I) and N,N′-di(3-pyridyl)succinamide via weak intermolecular interactions

Reactions of N,N′-di(3-pyridyl)succinamide (L) with AgOTf, AgTFA and AgNO₃ (OTf = triflate, TFA = trifluoroacetate) produced three coordination polymers {Ag(L)(OTf)·DMF·MeCN}_n (1·DMF·MeCN), {Ag(L)(TFA)·2H₂O}_n (2·2H₂O) and {[Ag(L)]₂(NO₃)₂}_n (3), respectively. In 1, two one-dimensional (1D) [Ag(L)] chains are joined by the Ag⋯Ag, π⋯π and hydrogen-bonding interactions to form a 1D double chain, which is further linked to other equivalent ones via the hydrogen bonding interactions to yield a three-dimensional (3D) structure. In 2, the 1D [Ag(L)] helical chains are connected by the Ag⋯O, π⋯π, CH⋯π and hydrogen-bonding interactions to afford a 3D framework. In 3, two kinds of 1D [Ag(L)] chains are linked by the Ag⋯O and hydrogen-bonding interactions to form a 3D structure. The luminescent properties of 1–3 along with L were also investigated.     

Preparation and Characterization of New Optically Active Poly(amide imide)s Derived from N,N’-(4,4’-Sulphonediphthaloyl)-bis-(s)-(+)-valine Diacid Chloride and Aromatic Diamines under Microwave Irradiation

Summary The present paper is an extension of microwave method describing the synthesis of the new optically active poly(amide-imide)s. The main focus of this work is the design of new effective microwave method for preparing optically active poly(amide-imide)s. Imide-acid (3) was synthesized by the reaction of 3,3,4,4-diphenylsulfonetetracarboxylic dianhydride (1) with (s)-(+)-valine (2) in acetic acid. The compound 3 was coverted to diacid chloride 4 by reaction with excess amount of thionyl chloride. Polycondensetion reaction of diacid chloride 4 with several aromatic diamines such as 4,4-sulfonyldianiline (5a), 4,4-diaminodiphenyl methane (5b), 4,4-diaminodiphenylether (5c), p-phenylenediamine (5d), m-phenylenediamine (5e), 2,4-diaminotoluene (5f) and 4,4-diaminobiphenyl (5g) was carried out in the presence of small amount of o-cresol under microwave irradiation as well as conventional heating method. We obtained a series of optically active poly(amide-imide)s with high yield and inherent viscosity ranging from 0.22-0.35 dL/g. These new polymers were characterized by FT IR, ¹H NMR, elemental analyses and specific rotation techniques.     

Electrochemical study of the stability of the electron-donor—acceptor (EDA) complex between N,N,N′,N′-tetramethyl-p-phenylendiamine and m-dinitrobenzene in acetonitrile

The stability constant of the EDA complex between N,N,N′,N′-tetramethyl-p-phenylendiamine and m-dinitrobenzene in acetonitrile has been studied by cyclic voltammetry and potentiometric titration at constant finite current. For comparison, spectral measurements were made. The spectroscopic techniques allowed us to assume the formation of a 1:1 EDA complex of which stability in acetonitrile is lower than that previously reported in chloroform. This solvent effect is expected for such weak complexes. The electrochemical techniques give a higher value of the stability constant in similar conditions. The possible causes of the discrepancies are discussed. However, the enthalpy and entropy values for the process closely agree in both electrochemical and spectroscopic methods. This is good evidence that both techniques are accounting for the same type of interaction. The electrochemical techniques, and particularly cyclic voltammetry, seem to be fast and sensible methods to study EDA complex interactions in polar aprotic solvents.