Pyridinedicarboxylic Acid Diamides as Selective Ligands for Extraction and Separation of Trivalent Lanthanides and Actinides: DFT Study

This article presents a general approach to solving the urgent practical problem of separation of 4f-(lanthanides, Ln³⁺) and 5f-elements (actinides, An³⁺) very similar in properties based on the DFT quantum-chemical supercomputer simulation of Ln³⁺ and An³⁺ complexes with polydentate nitrogen-containing heterocyclic ligands. The method allows to calculate the geometry parameters of ligands and complexes and the metal to ligand binding energies with accuracy, permitting a direct comparison of calculation results with the experimental data, and estimate selectivity factors for separation of Eu³⁺/Am³⁺ model pair cations (SF_Am/Eu) in extraction experiments on a semi-quantitative level.

The applicability of the method and the approach demonstrated by DFT-modeling (nonempirical PBE functional, extended relativistic full-electron basis set) of a large series of diamides of pyridine-2,6-dicarboxylic (dipicolinic) acid (L) with different substituents at the amide nitrogen atoms and in the pyridine cycle, as well as their complexes [LM]³⁺, (H₂O)_nM(NO₃)₃ (n = 3, 4), and LM(NO₃)₃ (M = Eu, Am).

Based on the theoretical analysis a new model is proposed that describes the mechanism of Ln³⁺ and An³⁺ extraction in two-phase system highly acidic water solution-organic solvent, according to which the formation of An³⁺ and Ln³⁺ complexes occurs at the water/organic interface as a substitution reaction of hydroxonium ion in a cavity of a protonated ligand for the metal cation.

Calculation results confirm the experimentally established higher extraction ability of dipicolinic acid diamides containing one aryl and one alkyl substituent at the amide nitrogen atoms compared to the N,N,N′,N′-tetraalkyl diamides (“effect of anomalous aryl strengthening”). Based on the simulation results the structure of the modified ligand L suggested that it should ensure maximum An³⁺/Ln³separation selectivity in the series of dipicolinic acid diamides.     

Solvent Extraction and Separation of Trivalent Lanthanides Using Cyphos IL 104, a Novel Phosphonium Ionic Liquid as Extractant

Solvent extraction of trivalent lanthanides from chloride solution using a novel ionic liquid Cyphos IL 104 (trihexyl(tetradecyl)phosphonium bis-2,4,4-(trimethylpentyl) phosphinate or [R₄PA]) has been investigated, while comparing the results with that of its precursors trihexyl(tetradecyl)phosphonium chloride [R₄PCl or Cyphos IL 101], Cyanex 272 [HA] and their equimolar mixture. The results also indicate very high extractability of Cyphos IL 104 toward trivalent lanthanides. Unlike the conventional acidic extractants, extraction of trivalent lanthanides with Cyphos IL 104 increases the equilibrium pH of the aqueous phase due to the preferential extraction of acid over the lanthanide ions. Extraction mechanism has been established by studying the extraction of neodymium(III) with the ionic liquid as a function of the concentrations of Cyphos IL 104 and chloride ions. Separation studies of trivalent lanthanides from a mixed solution containing 1 × 10^?4M each of La, Nd, Gd, and Lu with Cyphos IL 104 or Cyanex 272 indicate that Cyphos IL 104 is a better extractant in terms of extraction coefficient, but Cyanex 272 exhibits better selectivity toward heavier lanthanides. The prospects of stripping and regeneration of ionic liquid (Cyphos IL 104) have also been discussed in the present study.     

Separation of U(VI) and Pu(IV) from Am(III) and Trivalent Lanthanides with Tri-iso-amyl Phosphate (TiAP) as the Extractant by Using an Ejector Mixer-Settler

Counter-current solvent extraction runs have been carried out to develop a suitable flow sheet for fast reactor fuel reprocessing with 1.1M Tri-iso-amyl Phosphate (TiAP)/Heavy Normal Paraffin (HNP) as the solvent by using an ejector mixer-settler facility. A spent solvent of 1.1M TiAP/HNP used for earlier runs has been employed in the present study after the regeneration. Separation of U(VI) and Pu(IV) from Am(III) and lanthanides such as La(III), Pr(III), Nd(III), Sm(III), and Eu(III) as fission product representatives with the above solvent has been investigated with an optimized flow sheet. Stage profile data generated for the extraction and strip runs for the above separation have been reported. Overall and stage-wise mass balance data for the above runs are also discussed.     

二吡啶胺为配体的新型镍配合物的合成及结构

以2,2'-二吡啶胺(Hdpa)和对氨基苯甲酸钠(PABA为4-氨基苯甲酸阴离子)为原料,和氟化镍反应合成了一种新型的镍配合物[Ni(PABA)(Hdpa)2]F(CH3OH)。通过X-射线单晶衍射、红外光谱、元素分析、质谱(ESI),对该配合物进行了结构表征。晶体结构表明,该配合物为阴离子-阳离子型化合物。     

Synergistic Extraction of Lanthanides (III) with Mixtures of TODGA and Hydrophobic Ionic Liquid into Molecular Diluent

The extraction of lanthanides(III) from aqueous nitric acid solutions with N,N,N’,N’-tetra(n-octyl)diglycolamide (TODGA) and with mixtures of TODGA and the hydrophobic ionic liquid (IL) [C₄mim][Tf₂N] into 1,2-dichloroethane (DCE) has been investigated. The extraction efficiency of Ln(III) ions was greatly enhanced by the addition of a small amount of IL to an organic phase containing TODGA. The synergistic effect comes from the higher hydrophobicity of Ln(III) extracted species formed by TODGA and the weakly coordinating Tf₂N^? anions compared with those formed by TODGA and NO₃^? ions as the counter-anions. The partition of Tf₂N^? anions between the organic and aqueous phases is the dominant factor governing the extractability of lanthanides(III) with mixtures of TODGA and [C₄mim][Tf₂N]. The extraction of Ln(III) from aqueous nitric acid solutions by TODGA alone and its mixtures with [C₄mim][Tf₂N] into DCE can be described on the basis of the solvation extraction mechanism. However, in the extraction system with added [C₄mim][Tf₂N], the partition of Tf₂N^? between two immiscible phases and the interaction between HTf₂N and TODGA in the organic phase should be taken into account. Possible reasons of the antagonistic effect in the TODGA–[C₄mim][Tf₂N] extraction system are discussed.     

Synthesis,Characterization and Biological Evaluation of Transition Metal Complexes Derived from N,S Bidentate Ligands

Two bidentate NS ligands were synthesized by the condensation reaction of S-2-methylbenzyldithiocarbazate (S2MBDTC) with 2-methoxybenzaldehyde (2MB) and 3-methoxybenzaldehyde (3MB). The ligands were reacted separately with acetates of Cu(II), Ni(II) and Zn(II) yielding 1:2 (metal:ligand) complexes. The metal complexes formed were expected to have a general formula of [M(NS)₂] where M = Cu²⁺, Ni²⁺, and Zn²⁺. These compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and various spectroscopic techniques. The magnetic susceptibility measurements and spectral results supported the predicted coordination geometry in which the Schiff bases behaved as bidentate NS donor ligands coordinating via the azomethine nitrogen and thiolate sulfur. The molecular structures of the isomeric S2M2MBH (1) and S2M3MBH (2) were established by X-ray crystallography to have very similar l-shaped structures. The Schiff bases and their metal complexes were evaluated for their biological activities against estrogen receptor-positive (MCF-7) and estrogen receptor-negative (MDA-MB-231) breast cancer cell lines. Only the Cu(II) complexes showed marked cytotoxicity against the cancer cell lines. Both Schiff bases and other metal complexes were found to be inactive. In concordance with the cytotoxicity studies, the DNA binding studies indicated that Cu(II) complexes have a strong DNA binding affinity.     

Relationship Between Bond Strength and Crystallinity of High Polymers-Polyethylene, Polyethyleneterephthalate, and Nylon

The effect of crystallinity of polyethylene on the peel strength of aluminum plate-polyethylene-aluminum foil laminate was investigated. The 180° peel strength increased by rapid cooling with water, ice water, or liquid nitrogen after bonding with hot-melt polyethylene compared with slow cooling with air at room temperature. It was concluded that the increase of peel strength by rapid cooling was due to the decrease of modulus by the microcrystallization of polyethylene.

The tensile bond strength of steel-polyethyleneterephthalate (PET)-steel composite was investigated. The tensile bond strength increased about 10 times by rapid cooling of the composite bonded with hot-melt PET compared with slow cooling. On annealing the rapidly cooled composite over 100°C, the tensile bond strength decreased rapidly. It was concluded that the tensile bond strength decreases with the development of PET spherulite. Also in the case of Nylon 12, the tensile bond strength increased about 2 times by rapid cooling compared with slow cooling. In the case of Nylon 12, however, the tensile bond strengths of the both rapidly and slowly cooled specimens increased by annealing at high temperature.     

肉桂醛-2-呋喃甲酰腙钴配合物的合成、晶体结构及热稳定性

以肉桂醛-2-呋喃甲酰腙与Co Cl2·6H2O为原料,在不同的反应条件下合成得到两个钴配合物,并通过FTIR、热重分析、X-射线单晶衍射等手段对其进行了表征。X-射线单晶衍射结果表明:两个配合物均为四角双锥构型,属单斜晶系。配合物Co(L)2(H2O)2属P21/c空间群,晶胞参数为a=1.706 2(2)nm,b=1.059 17(13)nm,c=0.742 00(9)nm;β=101.738(2)°,V=1.312 9(3)nm3,Z=2。配合物Co(L)2(Imz)2属C2/c空间群,晶胞参数为a=2.481 4(2)nm,b=0.848 96(8)nm,c=1.936 96(18)nm;β=121.132 0(10)°,V=3.492 7(6)nm3,Z=4。热重分析表明,两个配合物均有较高的热稳定性。     

Current Understanding of the Relationship between Blood Donor Variability and Blood Component Quality

While differences among donors has long challenged meeting quality standards for the production of blood components for transfusion, only recently has the molecular basis for many of these differences become understood. This review article will examine our current understanding of the molecular differences that impact the quality of red blood cells (RBC), platelets, and plasma components. Factors affecting RBC quality include cytoskeletal elements and membrane proteins associated with the oxidative response as well as known enzyme polymorphisms and hemoglobin variants. Donor age and health status may also be important. Platelet quality is impacted by variables that are less well understood, but that include platelet storage sensitive metabolic parameters, responsiveness to agonists accumulating in storage containers and factors affecting the maintenance of pH. An increased understanding of these variables can be used to improve the quality of blood components for transfusion by using donor management algorithms based on a donors individual molecular and genetic profile.     

The Influence of Steric Effect,Alkyl Chain Length,and Donor Number of Solvents on the Extraction of Copper(II) Complexes with 1-Alkyl-4-Methylimidazoles

Abstract

The formation of Cu(II) complexes with 1-alkyl-4-methylimidazoles (where alkyl = butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl) has been studied by using the liquid-liquid partition method at 25°C and a fixed ionic strength of the aqueous phase (I = 0.5; (HL)NO₃, KNO₃). 2-Ethylhexanol, dichloromethane, chloroform, p-xylene, and toluene were used as a solvent. Stability constants, β_n, of the complexes in aqueous solution were determined as well as their partition ratios between the organic and aqueous phase. Under the influence of the steric effect, the methyl group in position 4 as well as the length of the alkyl group in position 1 of the ligands and electron-donating properties of solvents, both the polyhedral structure and the co-ordination numbers of the Cu(II) complexes are changed, thus resulting in an increase in the solvent/water partition ratios, P_n, of the complexes and lowering of the pH_1/2 of the extraction.     

基于含铜簇配位聚合物的制备及晶体结构

通过席夫碱配体2-羟基-3-甲氧基-苯甲醛缩烟酰肼(IAH)和碘化亚铜在溶剂热条件下得到新型的铜(I)配位聚合物[(Cu2I2)L]n。通过元素分析、红外光谱和热重分析等方法对该配合物进行了表征,并测定了它的单晶结构。配合物属三斜晶系,空间群P-1,a=7.998 8(8)?,b=12.642 3(12)?,c=17.919 7(17)?,α=89.528(2)°,β=89.528(2)°,γ=73.688 0(10)°,V=1 738.9(3)?~3,Z=2。     

Structure and stability of alkali gallates structurally reminiscent of hollandite

Single crystals of CsGa₇O₁₁, RbGa₇O₁₁, and RbGa₄In₅O₁₄ were grown from alkali halide melts and their structures were characterized by single crystal and powder X-ray diffraction. CsGa₇O₁₁ and RbGa₇O₁₁ adopt the same structure type, reminiscent of the hollandite structure type, as it contains nearly rectangular channels made up of two dimers of edge-sharing GaO₆ octahedra, and two corner-sharing octahedron/tetrahedron pairs. The structure of RbGa₄In₅O₁₄ is more complex and is comprised of indium octahedra, gallium trigonal bipyramids, and gallium tetrahedra, and contains similar sized tunnels as CsGa₇O₁₁ and RbGa₇O₁₁. CsGa₇O₁₁ and RbGa₄In₅O₁₄ were further characterized by TGA, ion exchange experiments, and DFT studies revealing that both structures are thermodynamically stable up to 850°C; however, CsGa₇O₁₁ decomposes to GaO(OH) xH₂O when heated in warm aqueous solutions. CsGa₇O₁₁ undergoes ion exchange in both an aqueous solution of RbCl and a RbNO₃ melt, as predicted by DFT studies, where the ion exchange is more extensive in the RbNO₃ melt.     

一维NiⅡ配合物的合成、结构及热稳定性

在甲醇-水溶剂中,用四溴代对苯二甲酸(H2TBTA)、1,3-二(4-吡啶基)丙烷(BPP)、硝酸镍为原料合成了一维链状配合物[Ni(BPP)2(TBTA)(H2O)2]n。该配合物晶体中NiII金属离子与两个BPP的两个N原子、两个H2TBTA中的两个羧基O原子及两个水分子中的O原子配位,形成六配位的变形八面体结构。晶胞参数:三斜晶系,P-1空间群,a=9.444(5),b=9.602(5),c=11.356(6),V=882.2(8)3,Z=1,Dcalc=1.828 mg/mm3,R1[I>2σ(I)]=0.0329,wR2(all data)=0.1058。对晶体进行热稳定性分析表明:配合物在122℃以下稳定性良好。     

以m-BrPhH_3 IDC为配体构筑的钴配合物的合成、晶体结构和热性能

采用溶剂热法使m-Br Ph H3IDC与Co(Ⅱ)合成了单核配合物:[Co(m-Br Ph H3IDC)2(2H2O)],采用元素分析、红外光谱以及单晶X-ray测试了其分子结构。进一步研究了这个配合物在空气中的热稳定性能。     

N,N-二甲基氨基甲烷二膦酸的合成及晶体结构

以二甲基甲酰胺、三氯化磷和亚磷酸为原料合成了同碳有机二膦酸———N,N-二甲基氨基甲烷二膦酸(DMAMDP)。研究了原料配比、温度、时间、水解用水量等条件对目标产物收率的影响。结果表明:n(DMF)∶n(PCl3)∶n(H3PO3)=1∶1∶1.5、反应温度为70°C、反应时间为30 min、用乙醇为溶剂析出产物时,目标产物的收率可达81.1%(以DMF计)。用乙醇/水的混合溶液重结晶,熔程为248~249°C。通过IR,31P NMR和1H NMR对产物进行了结构鉴定,并用X射线单晶衍射法确定了其单晶结构。     

Syntheses, Structures, and Luminescent Properties of Two Novel Coordination Polymers with Poly-Carboxylate and N-Heterocyclic Ligands

Two novel metal–organic coordination polymers {[Pb(CIPT)(1,4-BDC)]·2H₂O} _n 1 and {[Zn₂(IPDT)₂(1,4-BDC)₂(H₂O)].3H₂O} _n 2 [CIPT = 2-(3-chlorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline, 1,4-BDC = terephthalic acid, IPDT = 4-(1H-imidazo[4,5-f][1,10]phenanthroline-2-yl)-2,6-dimethoxyphenol] were obtained from hydrothermal reaction and characterized by elemental analysis, thermogravimetric (TG) analysis, IR and single-crystal X-ray diffraction. Both of the two coordination polymers exhibit one-dimensional (1D) infinite chain structures through non-covalent interactions, and the existence of hydrogen bonds interactions lead the 1D chain to 2D layer structures. It is noteworthy that the existence of hydrogen bonds reinforces the structural stability of the complexes 1 and 2, which can be proved by TG analysis. The photoluminescent study of coordination polymer 1 shows that it exhibits fluorescent emission band at 637 nm, which is red-shifted by 46 nm relative to the free ligand CIPT.     

Structure-Property Relationship of Polyimide Fibers with High Tensile Strength and Low Dielectric Constant by Introducing Benzimidazole and Trifluoromethyl Units

Copolyimide (co-PI) fibers with high strength and low dielectric constant are synthesized and prepared by introducing 2,2′-bis(trifluoromethyl)-4,4′-diaminobiphenyl (TFMB) and 2-(4-aminophenyl)-5-aminobenzimidazole (BIA) diamines into the rigid backbones. The resultant fibers not only exhibited excellent mechanical properties with a tensile strength of 2.627 GPa and an initial modulus of 96.786 GPa, but also possessed a dielectric constant as low as 2.433 at 10 GHz. The existence of intermolecular hydrogen-bonding interaction is confirmed by Fourier transform infrared spectroscopy, which has been considered as the leading factor responsible for the significantly improved mechanical properties of the co-PI fibers. 2D wide-angle X-ray diffraction (2D WAXD) is adopted to investigate the variation on the aggregation structure of PI fibers after the incorporation of fluorine group. The fibers with more TMFB content possessed a higher orientation degree together with a larger free volume fracture due to the combined effects of enhanced flexibility and the volume effect of trifluoromethyl groups. Meanwhile, the prepared PI fibers exhibit a 5% weight loss temperature ranging from 543 to 533 °C in the nitrogen atmosphere and a glass transition temperature ranging from 334 to 317 °C, revealing high thermal stability of co-PI fibers.     

钴配位聚合物Co[2,4-bis(2-(benzylacid)thiophenylmethyl)-1,5-dimethylbenze]2(pyridine)2的水热合成、晶体结构及热稳定性

在水、甲醇和N,N'-二甲基甲酰胺(DMF)的混合溶液中以2,4-双(2-(苯甲酸)苯巯甲基)-1,5-二甲苯(2,4-bis(2-(benzylacid)thiophenylmethyl)-1,5-dimethylbenze)、吡啶(pyridine)、硝酸钴为原料采用水热法合成了标题配合物co[2,4-bis(2-...     

NaEuSi_3O_7(OH)_2单晶的合成及结构解析

在水热条件下成功合成了一个铕硅酸盐晶体,其化学构成为NaEuSi_3O_7(OH)。其结构可以看作是由SiO_4四面体和EuO_6八面体相互连接而成的三维结构。每个EuO_6八面体通过桥氧相互连接而成平行于[010]方向的EuO_6八面体双链,SiO_4而四面体之间相互连接而形成的平行于[010]方向的SiO_4而四面体单链。EuO_6八面体双链和SiO_4而四面体单链之间通过氧原子相互连接而形成沿[010]方向的4,6元环的孔道结构,Na~+位于孔道的缝隙位置以平衡电荷。