Solvent Extraction of Alkali Metal Cations from Aqueous Solutions by Crown Ether Carboxylic Acids

Abstract

Competitive solvent extractions of alkali metal cations from aqueous solutions by the crown ether carboxylic acids sym-dibenzo-13-crown-4-oxyacetic acid, 2; sym-dibenzo-19-crown-6-oxyacetic acid, 3, and sym-dibenzo-14-crown-4-oxyacetic acid, 4, in chloroform have been conducted. Influences of aqueous phase pH and metal ion concentrations upon the concentrations of metals and complexing agent in the organic phase are assessed and compared with those reported for sym-dibenzo-16-crown-5-oxyacetic acid, 1. Extraction selectivity orders of K > Rb > Na ≈ Cs > Li, K > Rb ≥ Na ≈ Cs > Li, and K > Na > Rb > Cs ≈ Li were found for extractions using 2, 3, and 4, respectively. In terms of selectivity and metal extractability, 3 surpasses 1, 2, and 4.     

Effect of Ring-Size Variation within Dibenzocrown Ether Resins upon Ion-Pair Sorption of Alkali-Metal Cations from Aqueous and Aqueous Methanol Solutions

Abstract

A batch analysis method has been developed for evaluation of metal salt sorption by crown ether polymers. Selectivity in competitive alkali-metal chloride sorption by a series of formaldehyde condensation polymers of dibenzocrown ethers is influenced by the relationship between the crown ether cavity size and metal ion diameter, as well as the degree of hydration of the metal salt. Effective and selective sorption of KCl from the other alkali-metal chlorides was obtained with a dibenzo-18-crown-6 resin. Excellent sorption selectivity for the monovalent metal chlorides was noted for competitive ion-pair sorption of NaCl, KCl, MgCl₂, and CaCl₂ by this resin. This resin was examined as a stationary phase for selective column separation of KCl from alkali-metal chlorides and of KCl and NaCl from alkali-metal and alkaline-earth chloride mixtures in 80% methanol—20% water.     

Homogeneous Polymerisation of Methylmethacrylate Initiated by Alkali Metal Salts of Methanol and t-Butyl Alcohol in the Presence of Cryptands and Macrocyclic Crown Ether Compounds

The polymerisation of methylmethacrylate initiated by alkali alkoxides is greatly promoted in the presence of macrocyclic compounds, cryptands and crown ethers. The solubility in toluene and the reactivity of alkoxides is enhanced by these complexing agents. Polymerisations have been carried out in a non-polar solvent in the homogeneous phase.     

碱金属氯化物催化下甲醛与丙二腈Knoevenagel缩合反应的理论研究

采用量子力学计算中的密度泛函DFT方法,在B3LYP/6-311++G(d,p)水平上,研究了LiCl、NaCl及KCl催化条件下甲醛与丙二腈Knoevenagel缩合反应的机理。计算结果表明:动力学方面甲醛与丙二腈的缩合反应分两步进行,反应的第一步为整个反应的速度控制步骤;从热力学方面看,整个反应为放热反应。催化剂LiCl、NaCl、KCl对反应的第一步影响较大,促进了此步亲核反应的进行及活泼氢的迁移,使反应更容易进行。催化剂的加入降低了反应的势垒,且催化效果是LiCl好于NaCl,NaCl好于KCl。     

冠醚改性双金属氰化络合物的制备及其催化性能研究

以18-冠醚-6(18-Crown-6)为共聚络合剂制备了冠醚改性双金属氰化络合物(CDMC)催化剂,并研究了其对CO_2与环氧丙烷(PO)共聚反应的催化行为。结果表明,18-Crown-6不但能作为掩蔽剂消除K~+对双金属氰化络合物(DMC)催化剂活性的干扰,还可以改变DMC催化剂的形貌并有效降低DMC催化剂的结晶度。CDMC催化CO_2和PO共聚反应时活性达4 953g/gcat.和碳酸酯含量达39.7%。通过重复循环实验发现,CDMC催化剂在经化浆处理后,在第六次循环时催化活性仍能达到3 549g/gcat.。     

冠醚表面活性剂的合成

合成了冠醚表面活性剂正癸基 -12 -冠 -4和正癸基 -12 -冠 -5 ,其结构由红外、质谱、核磁确证。将来此类表面活性剂不仅可用于金属离子 (碱金属、碱土金属、稀土金属 )的分离与富集 ,还可用于有机合成中的相转移催化和胶团催化     

蓬勃发展的冠醚化学

简要介绍了冠醚的结构、性能,冠醚化学的产生、发展及应用。重点介绍了：①新型冠醚及其金属配合物的合成;②新型冠醚的选择性络合及其自组装;③新型冠醚的络合作用及催化作用。并展望了其广阔的应用前景。     

Comparative Equilibrium Studies on the Sorption of Metal Ions with Macroporous Resins Containing a Liquid Ion-Exchanger

Abstract

The distribution of five metal ions (M ^m+) including Fe(III), Co(II), Ni(II), Cu(II), and Zn(II) between dilute sulfate solutions and macroporous resins containing di(2-ethylhexyl) phosphoric acid (D2EHPA, HR) was investigated. Experiments were carried out as a function of aqueous pH, D2EHPA concentration in the resin phase, and temperature. The equilibrium data were numerically analyzed. It was shown that the sorption reaction could be described by assuming the formation of metal complexes with a general composition MR _m (HR) _n in the resin phase. For several systems a change of complex stoichiometry with temperature was observed and discussed. The apparent thermodynamic data for the formation of these complexes were also calculated.     

Separation of Zinc Isotopes by Liquid-Liquid Extraction Using a Crown Ether

Abstract

The zinc isotope effect in a liquid-liquid extraction system using dicyclohexano-18-crown-6 was investigated. The enrichment factor for a unit difference of mass number was ?_u = 0.018 as a maximum, which is greater than that for magnesium isotopes. The enrichment factor to eliminate ⁶⁴Zn from ⁶⁶Zn, ⁶⁷Zn, ⁶⁸Zn, or ⁷⁰Zn is over 0.036. The isotope with an odd mass number, ⁶⁷Zn, behaved differently from those with even mass numbers. This odd/even isotope effect was ?_O/E = 0.056. From the values of ?_u and ?_O/E, it was found that the crown ether separated the zinc isotopes more effectively on the basis of an odd or an even mass number than of mass difference. The separation factors vary with the concentrations of salt and/or conjugated acid in the initial aqueous phases of extraction. The optimal concentration necessary to obtain the largest separation factor had components of 2.0 M ZnCl₂ and 1.0 M HCl. The large value of ?_u for the high atomic number zinc and the notable ?_O/E make it clear that the vibration frequencies of the intramolecular bonds should have an isotope shift which is recognized in the orbital energy of the atoms.     

以非模板合成法——席夫碱法合成四氮杂冠醚大环化合物

在氢溴酸条件下,以丙酮、乙二胺为原料,采用非模板合成法———席夫碱法合成四氮杂大环席夫碱化合物（a）,再经NaBH4还原成5,5,7,12,12,14-六甲基-1,4,8,11-四氮杂环十四烷水合物（L）,并采用一个索氏提取器的替代装置改进了对（L）的分离方法,分离得到（L）的异构体（b）和（c）;对四氮杂大环席夫碱化合物在不同种酸（氢溴酸和高氯酸）条件下的合成方法进行了对比研究,用1H-NMR和13C-NMR证实了化合物（a）和（L）的结构。     

Ion-Pair Extraction of Alkali Mental Nitrate Salts by Lipophilic,Benzo-Substituted 24-Crown-8 Ethers

Abstract

The extraction of alkali metal nitrate salts by 24-crown-8 ethers bearing multiple benzo substituents has been surveyed in 1,2-dichloroethane diluent at 25 °C. The results reveal that the addition of benzo-substituents onto the 24-crown-8 increases both the extraction efficiency and the selectivity for the larger cations. Substitution of branched alkyl groups onto the benzo rings of 24-crown-8 ethers has a relatively small influence on their extraction properties.     

Studies on Sorption of Radiocesium on Copper-Hexacyanoferrate-Loaded Resins

Abstract

Copper hexacyanoferrate(II) was incorporated in the matrix of the strongly basic anion-exchange resin Indion-810 for the sorption of radiocesium from aqueous solutions. Its efficiency for the removal of cesium was tested under both static and dynamic conditions. The resin was found to be highly selective for radiocesium from a variety of salt and acid solutions. With the help of x-ray diffraction patterns, infrared spectrometry, thermal gravimetry, and differential thermal analysis, the interaction of copper hexacyanoferrate(II) with the quaternary amine of Indion-810 resin was investigated. Pilot-scale studies using this resin indicated that radiocesium can be effectively removed from thousands of bed volumes of spent fuel storage bay water.     

Treatment of Synthetic Crudes with Metal Chlorides and Metal Carbonyls

Abstract

The removal of problematic synthetic crude compounds with limited amounts of transition metal chlorides, carbonyls and hydrido carbonyls was investigated. A middle distillate fraction containing pure compounds of nitrogen and sulphur that are typical of this fraction was used. Chlorides of copper, iron, tin and zinc showed significant potential for removal of the nitrogen compounds and ethyl and phenyl mercuric chlorides reacted with these compounds at 200[ddot]C. These chlorides reacted with mercaptans and alkyl sulphides to varying degrees and with the exception of ethyl mercuric chloride had little effect on benzo and dibenzothiophene. However, the carbonyls of cobalt and manganese were quite promising for these thiophenes. Hydrido carbonyls of these metals were more favourable for the nitrogen compounds. There is evidence of competition for sites on the solid metal salts.     

Extraction of Alkali Metal Tetraphenylborates by Polyurethane Foam

Abstract

The extraction of alkali metal tetraphenylborates by polyurethane foam was investigated. The extractability sequences are K⁺ ≈ Rb⁺ > Cs⁺ and K⁺ ≈ Rb⁺ ≈ Cs⁺ for polyether and polyester foams, respectively. The high extraction of K⁺ by polyether foam can be explained by the cation chelation mechanism.     

Ion‐Selective Ionic Polymer Metal Composite (IPMC) Actuator Based on Crown Ether Containing Sulfonated Poly(Arylene Ether Ketone)

This study introduces the concept of ion selective actuation in polymer metal composite actuators, employing crown ether bearing aromatic polyether materials. For this purpose, sulfonated poly(arylene ether ketone) (SPAEK) and crown ether containing SPAEK with molar masses suitable for membrane preparation are synthesized. The synthesized polymers are characterized using Nuclear magnetic resonance (NMR) and fourier transform infrared spectroscopy (FTIR) spectroscopy, thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC). Ionic polymer metal composite (IPMC) actuators are fabricated by electroless chemical deposition of a platinum (Pt) layer on both sides of SPAEK and crown‐ether containing SPAEK membranes, resulting in electrode layers of around 120 nm thickness. Actuation experiments demonstrate cation specific responses and bending degrees of the IPMC actuators. Incorporation of crown ether units in the polymer backbone results in an improved and ion‐selective bending displacement compared with SPAEK actuators. S(25)C(50)PAEK actuators show an increased bending displacement of 28% for Na⁺ and 20% for K⁺ ions.

     

Cation Transport Through Liquid Membranes Mediated by Photoreactive Crown Ethers. Effects of Alkali Metal Cations on Their Photoreactivities and Transporting Properties

Photoreactivities and cation transporting properties of monomeric, dimeric, and polymeric crown ethers which contain cinnamoyl residues were investigated. Photochemical cycloaddition reaction of the cinnamoyl moieties was accelerated by NaCl or KCl for the dimeric and polymeric derivatives but not for the monomeric one. The dimeric and polymeric crown ethers after irradiation in the presence of KCl showed a significant enhancement in the transport rates for Rb⁺ cation.     

稀土冠醚络合物的研究与进展

本文描述了稀土冠醚络合物的性质及应用，报道了稀土冠醚络合物的研究进展及前景，就稀土离子选择何种冠醚为配体最稳定及其影响因素做了介绍，最后对其荧光性及其应用给予了概述。     

Studies of the Size-Selective Extraction of Alkali Metal Ions by the Synergistic Extraction System,Crown Ether-DI(2-Ethylhexyl) Phosphoric Acid-Benzene

Abstract

In order to take practical advantage of the size-selective cation-coordinating ability of the cyclic polyethers (crown ethers), experiments seeking a means of avoiding the problem of solubilizing a mineral-acid anion in a nonpolar organic diluent were performed. Mixtures of several known extractants and crown ethers were tried. Results presented indicate that organic soluble cation exchangers mixed in solution with crown ethers produce a synergistic extractant mixture that largely exhibits the size-selective properties expected of the crown ether. Data are presented for the extraction of macro concentrations of alkali metals by di(2-ethylhexyl) phosphoric acid—dicyclohexyl-18-crown-6 mixtures at a single pH, and at nonloading condition(σ metal cone < 0.04 M) as a function of pH, 2 to 6. In both cases potassium is synergized most strongly presumably because of its best fit to the crown ether cavity. Other data indicate, however, that the size-fit principle is not as consistent for all alkali metal ions and crown ethers as for potassium and dicyclohexyl-18-crown-6. Other effects such as competition for ion hydration and aqueous-phase distribution of the complex may have important effects that have not been elucidated.     

高效液相色谱手性冠醚固定相的制备研究

冠醚是具有空腔且非常好的识别能力的大环聚醚化合物。系统地研究了将R-(3,3′-二溴基-1,1′-二萘基)-20-冠-6涂覆在粗制硅胶、精制硅胶、大孔硅胶、苯环修饰粗制硅胶、苯环修饰精制硅胶、苯环修饰大孔硅胶、十八烷基修饰粗制硅胶、十八烷基修饰精制硅胶、十八烷基修饰大孔硅胶、氨丙基修饰粗制硅胶表面制备10种不同支撑体的手性固定相用于苯甘氨酸和对羟基苯甘氨酸的拆分研究。研究表明大孔硅胶以及氨丙基修饰硅胶直接涂覆冠醚的柱皆不能拆分这两种氨基酸,另外硅胶表面是否修饰、以及修饰的基团对手性柱的分离能力具有影响,不同来源的硅胶也强烈地影响着手性柱的拆分效率。     

Performance of Chelating Resins Containing Calixpyrroles in Sorption of Anions

Abstract

Characteristics and sorptive properties of three series of chelating resins having incorporated calixpyrrole ligands within their structures is reported. Two sets of resins were obtained by immobilization of calix[4]pyrrole or calix[4]pyrrole[2]thiophene on the beads of crosslinked (vinylbenzyl chloride)/divinylbenzene copolymer. The third series was synthesized by condensation of calix[4]pyrrole with formaldehyde. All resins displayed sorptive properties towards halide anions and cyanides in a non‐aqueous medium (acetonitrile). The resins displayed superior selectivity for fluoride anions and the selectivity sequence for the uptake of other anions depended on their ionic radii. The bigger ligand, calix[4]pyrrole[2]thiophene, showed an enhanced affinity for bigger anions, including iodide, which was not observed in the case of calix[4]pyrroles. Thus, the resin containing the larger ligand complexes the whole range of anions, but with poorer selectivities.