Macrocyclic Ionophores Research Articles

Solvent extraction studies of europium(III), ytterbium(III), and lutetium(III) with ionizable macrocyclic ligands and thenoyltrifluoroacetone

Solvent extraction behavior of Eu(III), Yb(III), and Lu(III) has been investigated by using thenoyltrifluoroacetone (TTA) as extractant in the presence of 1,7-diaza-4,10,13-trioxacyclopentadecane-N,N'-diacetic acid (DAPDA) and 1,10-diaza-4,7,13,16-tetraoxacyclooctadecane-N,N'-diacetic acid (DACDA) as macrocyclic ionophores. DAPDA and DACDA were chosen in this work in view of their unique complexation toward lanthanides. It was observed that in the presence of DAPDA (L), Eu(III) extracted predominantly as ternary complex (Eu(L)(TTA)), whereas Yb(III) and Lu(III) were extracted as mixed, binary Ln(TTA)/sub 3/ and ternary (Ln(L)(TTA)) complexes. On the other hand, in the presence of DACDA, Eu(III) formed mixed binary and ternary complexes in the organic phase, whereas Yb(III) and Lu(III) formed predominantly binary complexes. In contrast to the extraction in the presence of DAPDA/DACDA, heavier lanthanides, i.e., Yb(III) and Lu(III), were extracted much less compared to lighter lanthanides, i.e., La(III) and Nd(III), in the presence of ethylenediamine-N,N'-diacetic acid (EDDA), a structurally analogous noncyclic polyaminopolycarboyxlic acid.

ChemInform Abstract: COMPUTATIONAL DESIGN OF POLYLACTONE MACROCYCLIC IONOPHORES

Chemischer InformationsdienstVolume 14, Issue 39 Physical Organic Chemistry ChemInform Abstract: COMPUTATIONAL DESIGN OF POLYLACTONE MACROCYCLIC IONOPHORES S. LIFSON, S. LIFSONSearch for more papers by this authorC. E. FELDER, C. E. FELDERSearch for more papers by this authorA. SHANZER, A. SHANZERSearch for more papers by this author S. LIFSON, S. LIFSONSearch for more papers by this authorC. E. FELDER, C. E. FELDERSearch for more papers by this authorA. SHANZER, A. SHANZERSearch for more papers by this author First published: September 27, 1983 https://doi.org/10.1002/chin.198339090AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume14, Issue39September 27, 1983 RelatedInformation

The transfer of alkali metal ions across the water-nitrobenzene interface facilitated by neutral macrocyclic ionophores

The alkali metal ions transfer from water to the nitrobenzene phase containing macrocyclic neutral ionophores (crown polyethers, nonactin) has been investigated, applying the electrolysis at the interface of two immiscible electrolyte solutions (ITIES) in the single-sweep voltammetry mode. The stability constants of complexes formed in the non-aqueous phase have been determined from the peak voltammograms, as well as value of complex formation enthalpy. It has been concluded that the facilitated ion transfer in the temperature range 5–65°C is a diffusion-controlled process.

311 - A new model of membrane transport: electrolysis at the interface of two immiscible electrolyte solutions

A simple membrane model is the interface between water and an organic liquid immiscible with water, with a strongly hydrophilic electrolyte dissolved in the aqueous phase and a strongly hydrophobic electrolyte in the organic phase. This interface can be electrochemically polarized in the same way as the interface electrode |electrolyte solution using various modes of voltammetry or the galvanostatic method. A four-electrode potentiostatic system is required for such studies. An electrolyte dropping electrode, analogous to Heyrovsky's DME, was also constructed. The voltammograms fully resemble those obtained with metallic electrodes. The faradaic proceses studied so far are mainly connected with the transfer of hydrophobic ions across the interface. These processes are quite rapid and the half-wave potential of a particular ion is related to its standard Gibbs transfer energy. Observed electron-transfer effects model redox processes at membranes. Macrocyclic ionophores facilitate transfer of alkali metal ions across this interface. Very fast ion transfer as well as complex formation was observed in the systems under investigation so that, generally, the diffusion of the ionophore toward the interface and of the complex into the organic phase is the rate-controlling step, no surface reaction retarding the overall process. Apart from the investigation of membrane processes, this approach can be used for elucidation of processes in ion-selective electrodes and in phase-transfer catalysis.

A new model of membrane transport: Electrolysis at the interface of two immiscible electrolyte solutions

A simple membrane model is the interface between water and an organic liquid immiscible with water, with a strongly hydrophilic electrolyte dissolved in the aqueous phase and a strongly hydrophobic electrolyte in the organic phase. This interface can be electrochemically polarized in the same way as the interface electrode electrolyte solution using various modes of voltammetry or the galvanostatic method. A fourelectrode potentiostatic system is required for such studies. An electrolyte dropping electrode, analogous to Heyrovský's DME, was also constructed. The voltammograms fully resemble those obtained with metallic electrodes. The faradaic processes studied so far are mainly connected with the transfer of hydrophobic ions across the interface. These processes are quite rapid and the half-wave potential of a particular ion is related to its standard Gibbs transfer energy. Observed electron-transfer effects model redox processes at membranes. Macrocyclic ionophores facilitate transfer of alkali metal ions across this interface. Very fast ion transfer as well as complex formation was observed in the systems under investigation so that, generally, the diffusion of the ionophore toward the interface and of the complex into the organic phase is the rate-controlling step, no surface reaction retarding the overall process. Apart from the investigation of membrane processes, this approach can be used for elucidation of processes in ion-selective electrodes and in phase-transfer catalysis.

Electrochemical reduction of monovalent cation complexes of macrocyclic ionophores. II. Valinomycin and macrotetrolide complexes

The stability and selectivity of complex formation of natural macrocyclic ionophores with alkali metal ions and monovalent thallium ion was studied by polarography. With valinomycin both stability constants and homogeneous dissociation rate constants were determined from polarographic kinetic currents. The macrotetrolides gave diffusion controlled currents. The stability of their complexes increases with the degree of substitution from nonactin to trinactin. The properties of natural ionophores were compared wiht those of crown polyethers. The selectivity of complex formation of valinomycin almost coincides with its effect on the increase of the conductivity of bilayer lipid membranes.

Catalysis of ester aminolysis by macrocyclic ionophores

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCatalysis of ester aminolysis by macrocyclic ionophoresRichard D. Gandour, David A. Walker, Ashutosh Nayak, and George R. NewkomeCite this: J. Am. Chem. Soc. 1978, 100, 11, 3608–3609Publication Date (Print):May 1, 1978Publication History Published online1 May 2002Published inissue 1 May 1978https://doi.org/10.1021/ja00479a059RIGHTS & PERMISSIONSArticle Views97Altmetric-Citations17LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (259 KB) Get e-Alerts Get e-Alerts