Selective Transport of Alkali Metal Cations in Solvent Extraction by Proton-Ionizable Dibenzocrown Ethers

Abstract

Lipophilic crown ethers with pendant proton-ionizable groups are novel metal complexing agents for use in solvent extraction of alkali metal cations. A variety of dibenzocrown ether carboxylic acids and dibenzo crown phosphonic acid monoesters have been examined to probe the effect of structural variation within the complexing agent upon selectivity and efficiency in solvent extraction. Results from competitive solvent extractions of alkali metal cations from aqueous solutions into chloroform are summarized.     

FIA Potentiometric and Solvent Extraction Studies of Alkali Metal and Alkaline Earth Cation Complexation by bis(Tert-butylbenzo)-21-crown-7

Abstract

A flow injection analysis study of the potentiometric selectivity of bis[4(5)-tert-butylbenzo]-21-crown-7 (D(tBB)21C7) for cesium over the other alkali metal cations and three alkaline earth cations has been conducted. A PVC matrix membrane containing D(tBB)21C7 as an ionophore was coated on the tip of a silver wire incorporated in a flow cell. No selectivity for cesium over rubidium and only low selectivity over potassium were noted. However, very high selectivities for cesium over sodium, lithium, strontium, calcium, and magnesium were observed. Selectivity of D(tBB)21C7 in the solvent extraction of alkali metal cations was determined by the picrate extraction method. The percent extraction into deuteriochloroform decreased in the order cesium, rubidium > potassium » sodium » lithium. Thus good agreement was observed between the responses of D(tBB)21C7 towards alkali metal cations in polymeric membrane electrodes and in solvent extraction.     

Molecular Design of Crown Ethers. 22. Synthesis of Benzocrown Ether Derivatives and Their Solvent Extraction with Univalent／Bivalent Metal Picrates

Three novel benzocrown ether derivatives have been synthesized and their cation binding behavior with uniand bi-valent metal ions was evaluated by the solvent extraction of aqueous metal picrates. The obtained results indicate that the size-fit of crown ether and metal cation, and electron effect of the side arm attached to benzocrown ethers affect their cation binding ability and selectivity.     

环糊精衍生物在金属催化有机合成中的应用

综述了环糊精(包括α-环糊精,β-环糊精和γ-环糊精)衍生物在金属催化有机合成中的应用,主要包括其作为金属离子配体、金属纳米粒子稳定剂和反相相转移催化剂在氧化、水解、还原、偶联等金属催化反应中的应用.其中环糊精衍生物作为金属离子配体应用最广,由于环糊精部分与底物形成包结络合物,拉近了底物和具有催化活性的金属离子的距离,并固定了底物的反应部位,往往可以显著提高催化反应的反应速率,增强反应的区域选择性和对映选择性.     

Metal Ions Extraction with Glucose Derivatives as Chelating Reagents in Supercritical Carbon Dioxide

A series of glucose derivatives have been used as chelating reagents to extract metal ions in supercritical carbon dioxide. With perfluoro-1-octanesulfonic acid tetraethylammonium salt as additive, glucose derivatives were selective for Sr2 and Pb2 extraction in supercritical carbon dioxide.     

杯芳烃偶氮类衍生物对金属离子的萃取作用

通过杯芳烃的酚羟基的直接烃基化反应,在杯芳烃的下缘引入2,3′-二甲基-4-氨基偶氮苯发色团,得到了一系列杯芳烃偶氮衍生物(n=4,6,8)a-c.研究了它们对碱金属,碱土金属及过渡金属等十种金属离子的萃取作用.结果表明此类杯芳烃偶氮衍生物对过渡金属离子有良好的选择性识别作用,其中空腔较大的杯[8]芳烃偶氮衍生物c的萃取效果尤为显著.     

环糊精衍生物作为气相色谱固定相的发展及应用

从环糊精及其衍生物作为气相色的分离机理出发介绍了影响这固定相的因素及其分离应用的近期发展,共评述56篇文章。     

Synthesis of Cyclic Glycerol Ether Cyclodextrin Derivatives and Investigation of their Binding Properties with Drugs

Epichlorohydrin was reacted with cyclodextrins to form the non-cyclic and cyclic glycerol ethers of - and -cyclodextrin (abbreviated as glyc-CD). Cyclic substitution extends the cyclodextrin cavity in a way that is as rigid and non-polar as the cavity of the parent cyclodextrin. Derivatives with extended cavities should better accommodate large or odd shaped molecules. The binding of drugs to the new cyclodextrin derivatives was investigated, through degradation rate studies and solubilization studies, and compared to that of -cyclodextrin, -cyclodextrin and hydroxypropyl--cyclodextrin. The inclusion binding of small molecules such as acetazolamide, ethoxyzolamide and chlorambucil, in the glyc-CDs was either increased or decreased compared to the other cyclodextrins. However, larger molecules, such as indomethacin and hydrocortisone, always bound better to the glyc-CDs with up to 180% increase in the stability constant. The degradation rate within the cyclodextrin cavity was not affected by the above derivation.     

疏水性相转移手性溶剂萃取分离叔丁喘宁对映体

以四苯硼钠 (NaBPh4)为疏水性相转移试剂 ,研究了叔丁喘宁对映体分别在含 13种不同烷基链的L 酒石酸酯手性选择体水 有机溶剂两相系统中的萃取分配行为 ,考察pH和有机溶剂对分配系数 (K)和分离因子 (α)的影响。实验表明 :BPh-4与叔丁喘宁对映体阳离子形成疏水性复合盐 ,促进叔丁喘宁对映体在有机溶剂中的溶解 ,提高了分配系数 ;L 酒石酸酯与叔丁喘宁对映体Ⅱ形成非对映体复合物的稳定性比与对映体Ⅰ形成的非对映体大 ;随着L 酒石酸酯烷基链的增长 ,分配系数和立体选择性增强 ;3类溶剂的萃取性能为醇>1,2 二氯乙烷 >烷烃 ,并随着醇碳原子数的增加 ,两对映体的分配系数和分离因子增大 ;pH值的影响很大。     

用Excel进行溶剂萃取工艺计算

介绍了溶剂萃取工艺计算的Excel电子表格方法，无需手工绘图和编程就可方便地得到计算结果，这种方法可用于教学和工程计算。     

Metal Recognition Driven by Weak Interactions: A Case Study in Solvent Extraction

Tuning the affinity of a medium for a given metallic cation with the sole modification of weak interactions is a challenge for molecular recognition. Solvent extraction is a key technique employed in the recovery and purification of valuable metals, and it is facing an increased complexity of metal fluxes to deal with. The selectivity of such processes generally relies on the use of specific ligands, designed after their coordination chemistry. In the present study, we illustrate the possibility to employ the sole control of weak interactions to achieve the selective extraction of Pd^II over Nd^III: the control over selectivity is obtained by tuning the self‐assembly of the organic phase. A model is proposed, after detailed experimental analysis of molecular (XRD, NMR) and supra‐molecular (SAXS) features of the organic phases. We thus demonstrate that Pd^II extraction is driven by metal coordination, whereas Nd^III extraction requires aggregation of the extractant in addition to metal coordination. These results are of general interest for the applications which rely on the stabilization of metals in organic phases.     

改性环糊精气相色谱手性固定相拆分对映体的选择性及拆分机理的讨论

改性环糊精气相色谱手性固定相拆分对映体的选择性及拆分机理的讨论周昕，万宏，欧庆瑜（中国科学院兰州化学物理研究所兰州７３００００）１前言自１９８８年Ｋｏｎｉｇ￣［１］等人成功地将改性环糊精用于毛细管气相色谱固定相拆分对映体以来，环糊精衍生物以其高选择性...     

Synthesis and Characterization of β—Cyclodextrin Bonded Metal Porphyrins

Reactions of 5-(p-aminophenyl)-10,15,20-triphenyl porphyrin (1) with Ru3(CO)12 or M(OCOCH3)2 (M=Ni,Mn) afforded metalloporphyrins(4-6),respectively.6-Deoxy-6-io-do-β-cyclodextrin(2) and mono(6-O-trifluoromethanesulfonyl) permethylated β-cyclodextrin(3) reacted with complexes 4-6 to give β-cyclodextrin bonded metal porphyrins (7-9) and permethylated β-cyclodextrin bonded me-tal porphyrins (10-12) respectively.These new complexes were identified by MS,IR,UV-visible and ^1H NMR spectra,and elemental analysis.     

壳聚糖及其衍生物对重金属离子的吸附

壳聚糖的结构中含有大量的—NH₂和—OH,因此其对重金属离子有优良的吸附作用。但是作为天然高分子物质,壳聚糖的吸附性能又受到其自身物理形态、原料来源、脱乙酰度及体系pH值的影响,因此,对其进行物理和化学改性是提高壳聚糖吸附性能、扩大应用范围的必要手段。本文综述了壳聚糖的改性方法及其衍生物对重金属离子吸附作用的研究进展,并对其在重金属污染废水处理方面的前景作了展望。     

Synthesis,Alkali Metal Picrate Extraction Properties,and X-Ray Crystal Structure of a Novel,Cage-Annulated Monoaza-18-Crown-6 Host

Compound 5, a cage-annulated monoaza-18-crown-6 macrocyclic polyether, has been synthesized, and its alkali metal picrate extraction capabilities have been assessed relative to those of the parent monoaza-18-crown-6 host system. It was observed that both 5 and monoaza-18-crown-6 are selective K⁺ picrate extractants; however, 5 appears generally to be a somewhat more efficient alkali metal picrate extractant than monoaza-18-crown-6. Interestingly, both the avidity and selectivity of 5 toward extraction of alkali metal picrates from aqueous solution into CHCl₃ appears to be pH dependent. In addition, the X-ray crystal structure of an unusual hydronium ion complex of 5 [i.e., 5(HCl)(H ₂ O)-(CHCl ₃ ) ₂] has been determined. The X-ray structure thus determined is compared with the corresponding structure of 5(HCl)(H ₂ O) that has been calculated via application of B3LYP Density Functional Theory.     

Cations in a Molecular Funnel: Vibrational Spectroscopy of Isolated Cyclodextrin Complexes with Alkali Metals

The benchmark inclusion complexes formed by α‐cyclodextrin (αCD) with alkali‐metal cations are investigated under isolated conditions in the gas phase. The relative αCD‐M⁺ (M=Li⁺, Na⁺, K⁺, Cs⁺) binding affinities and the structure of the complexes are determined from a combination of mass spectrometry, infrared action spectroscopy and quantum chemical computations. Solvent‐free laser desorption measurements reveal a trend of decreasing stability of the isolated complexes with increasing size of the cation guest. The experimental infrared spectra are qualitatively similar for the complexes with the four cations investigated, and are consistent with the binding of the cation within the primary face of the cyclodextrin, as predicted by the quantum computations (B3LYP/6‐31+G*). The inclusion of the quantum‐chemical cation disrupts the C₆ symmetry of the free cyclodextrin to provide the optimum coordination of the cations with the ‐CH₂OH groups in C₁, C₂ or C₃ symmetry arrangements that are determined by the size of the cation.     

电动多通道切换分析系统在溶剂萃取分析中的应用

采用电动多通道切换分析系统,完成了水中铜的在线显色、溶剂萃取和光度测定,并证明了其应用的可行性;通过流路中切换器件的组合和控制软件的编写,该流动分析系统具有简便、灵活、多功能和易控制等特点;本分析系统由1台电渗泵和4个电磁切换阀组成;电渗泵是一种无脉动的液流驱动装置,易于计算机控制,更适用于多通道切换分析系统;本文还对有机泵载流及其添加剂进行了探讨;以水中铜的测定为例．方法的检出限为0．03mg/L．回收率在92％～96％范围．测样频率20样／h。     

杯芳烃酰胺类衍生物对金属离子的萃取性能

以吗啉和六氢吡啶修饰的四种对叔丁基杯[n]芳烃酰胺类衍生物(n=6,8)为萃取试剂,研究了它们对Na+,K+及部分过渡金属等十种金属离子的萃取作用.结果表明此类杯芳烃酰胺类衍生物对过渡金属离子有良好的选择性识别作用.其中,吗啉取代基修饰的杯[8]芳烃萃取效果最好.     

环糊精衍生物在液相有机合成中的应用

综述了环糊精(包括α-环糊精、β-环糊精和y-环糊精)衍生物在液相有机合成中的应用,主要包括其作为人工合成酶、超分子光学手性源、亲偶极体和微通道反应器在氧化、水解、还原、光催化异构化、1,3-偶极环加成等反应中的应用.其中环糊精衍生物作为人工合成酶应用最广,该催化剂中起催化作用的为环糊精衍生物的修饰基团.与环糊精母体相比,修饰基团的引入增加了环糊精分子中官能团的种类和数量,拓展了环糊精在液相有机合成中的应用,并提高了催化反应的催化活性和选择性.