AbstractFrom pH measurements in a simulated potentiometric titration the protonation constants for the title ligand (I) and the stability constants of its complexes with the lanthanoids La‐Lu are determined.

The protonation constants (α's) and the stability constants (K's) of diethylenetriamine-N,N,N′,N″-tetraacetic acid-N″-propionic acid (DTTAP) and its anion-lanthanide complexes, respectively, have been determined experimentally, providing information about the nature of chelation across the lanthanide series. The stability constants indicate that DTTAP can participate in a successful separation of Am from the lanthanides.

Chemischer InformationsdienstVolume 17, Issue 26 Article ChemInform Abstract: Effect of Changes in the Ligand′s Backbone Moiety on Formation Constants of 1:1 Nickel, Copper, Zinc, and Cadmium Chelates J. E. POWELL, J. E. POWELLSearch for more papers by this authorD. R. LING, D. R. LINGSearch for more papers by this authorP.-K. TSE, P.-K. TSESearch for more papers by this author J. E. POWELL, J. E. POWELLSearch for more papers by this authorD. R. LING, D. R. LINGSearch for more papers by this authorP.-K. TSE, P.-K. TSESearch for more papers by this author First published: July 1, 1986 https://doi.org/10.1002/chin.198626086AboutPDF 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 onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume17, Issue26July 1, 1986 RelatedInformation

Chemischer InformationsdienstVolume 17, Issue 27 Article ChemInform Abstract: Complexes of Rare-Earth Elements with 1,3-Diamino-2-hydroxypropane- N,N,N′,N′-tetraacetic Acid J. E. POWELL, J. E. POWELLSearch for more papers by this authorD. R. LING, D. R. LINGSearch for more papers by this authorP.-K. TSE, P.-K. TSESearch for more papers by this author J. E. POWELL, J. E. POWELLSearch for more papers by this authorD. R. LING, D. R. LINGSearch for more papers by this authorP.-K. TSE, P.-K. TSESearch for more papers by this author First published: July 8, 1986 https://doi.org/10.1002/chin.198627075Read the full textAboutPDF 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. Volume17, Issue27July 8, 1986 RelatedInformation

AbstractLn" Separations in Cation‐Exchange Elutions.

AbstractPolyamino Polycarboxylate Complexes.

AbstractDie Darstellungen der Liganden (I) und (II) aus Bis‐[3‐aminopropyI]‐ether, AlHg‐Reduktionsprodukt von Bis‐[2‐cyanoethyl]‐ether, bzw. Bis‐[3‐aminopropyl]‐methylamin und überschüssiger Monochloressigsäure werden detailliert beschrieben.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTComplex formation of lanthanide polyaminopolycarboxylatesP. K. Tse, J. E. Powell, M. W. Potter, and H. R. BurkholderCite this: Inorg. Chem. 1984, 23, 10, 1437–1440Publication Date (Print):May 1, 1984Publication History Published online1 May 2002Published inissue 1 May 1984https://pubs.acs.org/doi/10.1021/ic00178a027https://doi.org/10.1021/ic00178a027research-articleACS PublicationsRequest reuse permissionsArticle Views173Altmetric-Citations8LEARN 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 InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts

Data for the resolution of americium from europium and terbium using 2,2′-diaminodiethylether-N,N,N′,N′-tetraacetate and 1,5-diaminopentane-N,N,N′,N′-tetraacetate are reported along with values of the formation constants of the La-Lu and Y chelates of the latter. It is shown that the minimum single-stage separation factor for Am3+ from Ln3+ cations, using 2,2′-diaminodiethylether-N,N,N′,-N′-tetraacetate with Dowex 50 resin, exceeds 1.7 for all Am-Ln pairs, and runs as high as 350 in the case of Am3+, La3+. The minimum of 1.7 occurs at Eu3+ in the lanthanon sequence. A novel separation of Am3+, Cm3+ and heavier actinons from each other and from all the lanthanons and yttrium appears to be feasible.

The consecutive stepwise formation constants of the 1:1, 2:1, and 3:1 chelate species formed by the interaction of 2,3-dihydroxy-2,3-dimethylbutanoato anions with the tripositive lanthanon and yttrium cations were determined potentiometrically at an ionic strength of 0.1 (KNO3) and 25°C. The results indicate that at least three different coordination modes, one tridentate and two bidentate, are in evidence.

Publisher Summary This chapter discusses recent progress in means of isolating individual lanthanides and yttrium. The chapter discusses well-developed processes for the preliminary treatment of rare earth mixtures. The lanthanides comprise a series of inner-transition elements in which the number of 4-f electrons increases from 1 to 14. The main effect of increasing the number of electrons in this internal energy sublevel, as the nuclear charge increases, is to gradually decrease the cationic radius of consecutive Ln3+ ions, so that they range in size from that of La3+ to that of Sc3+. Because of the remarkable similarities in their cationic charge and their radii, lanthanons form many isomorphic series of compounds, and are always found as complex mixtures (not always of exactly the same composition) in rocks and minerals that comprise the earth's crust. The problem of separating them by reactions in aqueous media is aggravated further by the fact that increased charge density, which accompanies lanthanide contraction, promotes a greater overall degree of aquation and renders individual hydrated cationic radii even more similar.

The solvent extraction of lanthanides into chloroform solutions of 2,5-dimethyl-2-hydroxyhexanoic has been studied. The light lanthanides can be extracted by forming complexes with the acid anion. The extracted metal species is highly aggregated. This extraction has a solubility limit which increases with the addition of unionized acid. If the unionized acid-to-metal ratio becomes too great, extraction first occurs followed by slow precipitation of the metal salt. The heavy lanthanides do not extract from solutions of the acid and its potassium salt, but form aqueous emulsions and precipitates. In the presence of the organic soluble tetrabutylammonium ion, the heavy lanthanides can be extracted. At the tracer level, neodymium is extracted primarily as NdA3(HA)5 and (NdA3)2(HA)q. The chloroform-water acid partition constant, te chloroform acid dimerization constant, and the stability constants of the light lanthanide carboxylates are also reported.

AbstractAus dem Ketol (I) entsteht nach verschiedenen Verfahren das Cyanhydrin (II), dessen Ausbeuten optimiert werden.

AbstractDie Titelverbindung wurde mit 1 1% Ausb. nach einer abgewandelten Literaturmethode durch Carboxymethylierung von Benzylethylendiamin mit Formaldehyd und NaCN dargestellt und durch Ionenaustausch gereinigt.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCyanohydrin synthesis of 2,3-dihydroxy-2,3-dimethylbutanoic acidJack E. Powell, Carl Osuch, Harvey R. Burkholder, Santi Kulprathipanja, James H. Miller, Leon G. Stadtherr, and Russell G. BaughmanCite this: J. Org. Chem. 1978, 43, 16, 3166–3169Publication Date (Print):August 1, 1978Publication History Published online1 May 2002Published inissue 1 August 1978https://pubs.acs.org/doi/10.1021/jo00410a015https://doi.org/10.1021/jo00410a015research-articleACS PublicationsRequest reuse permissionsArticle Views312Altmetric-Citations5LEARN 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 InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Abstract The stability constants of the rare-earth complexes with 2-ethyl-2-hydroxy-3-methylbutyric acid have been determined potentiometrically at 25.0 °C and at an ionic strength of 0.10, with sodium perchlorate as the supporting electrolyte.

Chemischer InformationsdienstVolume 7, Issue 22 Physical Organic Chemistry ChemInform Abstract: THE CRYSTAL AND MOLECULAR STRUCTURE OF DIAQUOBIS(2,3-DIHYDROXY-2-METHYLPROPANOATO)COPPER(II) J. H. MILLER, J. H. MILLERSearch for more papers by this authorJ. E. POWELL, J. E. POWELLSearch for more papers by this authorR. A. JACOBSON, R. A. JACOBSONSearch for more papers by this authorS. KULPRATHIPANJA, S. KULPRATHIPANJASearch for more papers by this author J. H. MILLER, J. H. MILLERSearch for more papers by this authorJ. E. POWELL, J. E. POWELLSearch for more papers by this authorR. A. JACOBSON, R. A. JACOBSONSearch for more papers by this authorS. KULPRATHIPANJA, S. KULPRATHIPANJASearch for more papers by this author First published: June 1, 1976 https://doi.org/10.1002/chin.197622042AboutPDF 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. Volume7, Issue22June 1, 1976 RelatedInformation

The crystal and molecular structure of diaquobis(2,3-dihydroxy-2-methylpropanoato) copper(II) has been determined by three-dimensional X-ray analysis. The compound crystallizes in the monoclinic space group C2/c, with a = 5.688 ± .006 Å, b = 20.79 ±.03 Å, c = 10.569 ± .016 Å, β = 94.55 ±.06°, and Z = 4. The structure was solved by direct methods and refined by full-matrix least-squares procedures to a final discrepancy factor R = .090 for 860 observed reflections (10>2σ(I0)). The geometry around the copper is distorted octahedral, with the two waters occupying the axial positions. Both ligands coordinate bidently, forming chelate rings incorporating the 2-hydroxy oxygen. The other hydroxy oxygens are not bound to the copper. There appears to be extensive hydrogen bonding in both the a and c directions with long contacts in the b direction.

α,β,β′-Trihydroxyisobutyramide (2,3-dihydroxy-2-hydroxymethylpropanamide) melting point 107.5–108°, has been prepared from 1,3-dihydroxy-2-propanone via formation and partial hydrolysis of its cyanohydrin. After isolation by ion-exclusion techniques and crystallization from water and ethanol-water mixtures, the amide was converted nearly quantitatively to α,β,β′-trihydroxyisobutyric acid (2,3-dihydroxy-2-hydroxymethylpropanoic acid), melting point 117–117.5°, by boiling with excess aqueous NaOH followed by cation-exchange elimination of Na+ and any unevolved NH3 on H+-form Dowex 50. Proton NMR spectra for both amide and acid were recorded.