Electrochemical synthesis of aldehydes and acetals from α-phenylthiocarboxylic acid

α-Phenylthiocarboxylic acids were converted to the corresponding aldehydes or acetals with oxidative decarboxylation and desulfurization by electrolysis.     

Ion-exchange separation and spectrophotometric determination of traces of gold

Summary A combined ion-exchange — spectrophotometric method has been developed for the separation and determination of traces of Au(III) in seven metal ions: Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Se(IV) and Cd(II). Au(III) is adsorbed selectively on a DEAE column from dilute chloride solution, while other metal ions pass through the column. Au(III) is recovered by elution with 1M hydrochloric acid. Traces of Au(III) in the effluent are determined by a new spectrophotometric method, which is based on the formation and extraction of Au(III) — azide — methylene blue complex. Separations of traces of Au(III) from 1000-fold of Pd(II) and Pt(IV) and 10000-fold of Hg(II) are also effected on a DEAE column in mixed methanol 1M hydrochloric acid medium (8 2). While Pd(II), Pt(IV) and Hg(II) are retained on the column, Au(III) adsorbs very weakly, so that the separations can be accomplished easily.

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Zusammenfassung Eine mit Ionenaustausch kombinierte spektrophotometrische Methode zur Trennung und Bestimmung von Goldspuren neben sieben verschiedenen Metallionen wurde ausgearbeitet, nämlich neben Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Se(IV) und Cd(II). Das Gold wird an einer Säule aus Diäthylaminoäthylzellulose (DEAE) aus verdünnter Chloridlösung adsorbiert, wobei die anderen Metalle die Säule passieren. Durch Elution mit 1-m Salzsäure wird das Gold wieder gewonnen. Goldspuren im Effluenten werden mit Azid und Methylenblau komplex gebunden und so spektrophotometriert. Von der 1000fachen Menge Pd(II) und Pt(IV) sowie der 100000fachen Menge Hg(II) können Goldspuren auch aus Methanol + 1-m Salzsäure (12) mit einer DEAE-Säule abgetrennt werden. Während Pd(II), Pt(IV) und Hg(II) an der Säule festgehalten werden, wird Au(III) nur sehr schwach adsorbiert, so daß die Trennung leicht gelingt.

     

Determination of uranium and thorium in phosphate rocks by a combined ion-exchange — Spectrophotometric method

Summary Determination of Uranium and Thorium in Phosphate Rocks by a Combined Ion-Exchange — Spectrophotometric Method A selective anion-exchange separation and Spectrophotometric method has been developed for the determination of uranium and thorium in phosphate rocks. About 0.2 g of rock sample is decomposed with nitric acid. Uranium and thorium are adsorbed by anion-exchange on an Amberlite CG 400 (NO₃ ^–) column from the sample solution adjusted to 2.5M in magnesium nitrate and 0.1M in nitric acid. Uranium and thorium are eluted consecutively with 6.6M nitric acid and 0.1M nitric acid, respectively. Uranium and thorium in the respective effluents are determined spectrophotometrically with Arsenazo III. Results are quoted on uranium and thorium in NBS standard phosphate rock and others.     

Determination of phosphorus in silicate rocks by flow injection method of analysis

Summary A flow injection spectrophotometric method has been developed for the determination of phosphorus in silicate rocks. A rock solution is prepared by fusion with a mixture of lithium carbonate and boric acid and subsequent dissolution with l M hydrochloric acid. An aliquot of the sample solution is injected directly into the flow system, which consists of formation of heteropolyacids of molybdenum and antimony, reduction with ascorbic acid, and subsequent measurement of the absorbance of blue species. It permits semi-automated analysis of a variety of silicate rocks for phosphorus. Results obtained for standard rocks were in good agreement with the recommended values. The throughput comes out 20 samples per h.

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Bestimmung des Phosphors in Silikatgestein durch Flie-Injektions-Analyse

Zusammenfassung Ein Verfahren zur spektrophotometrischen Phosphorbestimmung in Silikatgestein mittels Fließinjektion wurde entwickelt. Das Gestein wird mit einer Mischung aus Lithiumcarbonat und Borsäure aufgeschlossen und in 1 M Salzsäure gelöst. Ein aliquoter Teil der Lösung wird unmittelbar in das fließende System injiziert, worin Heteropolysäuren aus Molybdän und Antimon gebildet, mit Askorbinsäure reduziert und die Absorbanz der blauen Farbe gemessen wird. Dies ermöglicht die halbautomatische Analyse verschiedener Silikatgesteine zur Phosphorbestimmung. Die Resultate von Standardproben stimmen mit den vorgeschriebenen Werten gut überein. In der Stunde können 20 Proben durchgesetzt werden.

     

Selective determination of yttrium in geological materials by ion-interaction chromatography

Selective separation and determination of yttrium in rare earth ores have been achieved by high performance ion-interaction chromatography. Ores are decomposed by sulfuric acid and the rare earths are precipitated in a group as oxalates. Yttrium is then separated from the other rare earths on a C-18 bonded phase silica column modified with 1-octanesulfonate by linear concentration gradient elution for 20 min with 0.15 to 0.40M glycolic acid(pH 3.5). Yttrium elutes at about 10 min between samarium and neodymium, being separated selectively from all the rare earths as well as scandium, thorium and uranium. Post-column reaction detection and quantitation with Arsenazo III [2,7-bis(2-arsonophenylazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid] are carried out at 650 nm. Quantitative results are quoted for yttrium in sophisticated, synthetic rare earth mixtures, monazite and xenotime.     

Reactions of [(eta(6)-arene)RuCl(2)](2) with Aromatic Phosphines Containing Methoxy Groups in 2,6-Positions

Reactions of [(eta(6)-arene)RuCl(2)](2) 1 (arene = p-cymene (a), 1,2,3,4-Me(4)C(6)H(2) (b), 1,2,3-Me(3)C(6)H(2) (c)) with tris(2,6-dimethoxyphenyl)phosphine (TDMPP) led to loss of two molecules of CH(3)Cl to give (eta(6)-arene)Ru[{2-O-C(6)H(3)-6-OMe}(2){C(6)H(3)(OMe)(2)-2,6}], 2a-c, which contains a trihapto ligand (eta(3)-P,O,O) derived from TDMPP, whereas the 1,3,5-Me(3)C(6)H(3) (1d), 1,2,3,5-Me(4)C(6)H(2) (1e), and C(6)Me(6) (1f) complexes did not react with TDMPP. The structures of 2a and 2b were confirmed by X-ray analyses: for 2a, a = 11.691(2) ?, b = 15.228(2) ?, c = 10.320(1) ?, alpha = 95.93(1) degrees, beta = 113.783(9) degrees, gamma = 83.86(1) degrees, triclinic, P&onemacr;, Z = 2, R = 0.051; for 2b, a = 17.79(2) ?, b = 15.43(1) ?, c = 20.93(1) ?, beta = 91.25(8) degrees, monoclinic, P2(1)/n, Z = 8, R = 0.056. Bis(2,6-dimethoxyphenyl)phenylphosphine (BDMPP) reacted with 1a, 1b, and 1d at room temperature to give (eta(6)-arene)RuCl[PPh(2-O-C(6)H(3)-6-OMe){C(6)H(3)(OMe)(2)-2,6}], 3a,b,d, which contains a dihapto (eta(2)-P,O) ligand derived from BDMPP by an X-ray analysis of 3a: a = 12.33(1) ?, b = 14.246(8) ?, c = 11.236(9) ?, alpha = 91.47(8) degrees, beta = 117.28(6) degrees, gamma = 111.70(6) degrees, triclinic, P&onemacr;, Z = 2, R = 0.040. A similar reaction with 1f recovered the starting materials, but that in refluxing MeCN produced [(eta(6)-C(6)Me(6))Ru[PPh(2-O-C(6)H(3)-6-OMe}(2)], 4f, containing a trihapto (eta(3)-P,O,O) ligand derived from BDMPP. Complex 1d reacted with BDMPP at reflux in MeCN/CH(2)Cl(2) and resulted in a loss of an arene ring to give a five-coordinate complex, Ru[eta(2)-P,O-PPh(2-O-C(6)H(3)-6-OMe){C(6)H(3)(OMe)(2)-2,6}](2)(MeCN), 5. Treatment of (2,6-dimethoxyphenyl)diphenylphosphine (MDMPP) with 1f gave (eta(6)-C(6)Me(6))RuCl[eta(2)-P,O-PPh(2)(2-O-C(6)H(3)-6-OMe)],6f, and that with 1b gave (eta(6)-1,2,3,4-Me(4)C(6)H(2))RuCl[eta(2)-P,O-PPh(2)(2-O-C(6)H(3)-6-OMe}], 6b, and (eta(6)-1,2,3,4-Me(4)C(6)H(2))RuCl(2)[eta(1)-P-PPh(2){C(6)H(3)(OMe)(2)-2,6}],7b. The phosphine ligand of 6b acted as a bidentate ligand derived from MDMPP: a = 8.074(4) ?, b = 16.816(3) ?, c = 18.916(4) ?, beta = 94.05(3) degrees, monoclinic, P2(1)/n, Z = 4, R = 0.051. Transformation of 7b to 6b readily occurred accompanying an elimination of MeCl. Reaction of 1a with MDMPP eliminated an arene ring to give the octahedral compound RuCl(2)[eta(2)-P,OMe-PPh(2){C(6)H(3)(MeO)(2)-2,6}](2), 8. An X-ray analysis of 8 showed that two MDMPP ligands were in a cis-position: a = 10.596(14) ?, b = 27.586(12) ?, c = 13.036(8) ?, beta = 108.17(7) degrees, monoclinic, P2(1)/n, Z = 4, R = 0.035.     

Dry-column chromatography of uranium. Application to chemical analysis of monazite and phosphate rock for uranium

Summary A dry-column Chromatographic technique has been applied to the separation of uranium from complicated matrices. It has been demonstrated that operating parameters of thin-layer chromatography on silanized silica gel in isopropyl ether-tetrahydrofuran-nitric acid (65203) can be transferred to this technique. Chromatograms are thus easily developed on dry packed column with the solvent system of the type used in the TLC. Uranium is eluted off the column and determined with Arsenazo III spectrophotometrically. The technique is successfully applied to the determination of uranium in monazite and phosphate rock samples with good precision and accuracy.

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Trockensäulenchromatographie des Urans. Anwendung zur chemischen Analyse von Monazit und Phosphorit

Zusammenfassung Zur Abtrennung des Urans aus komplizierten Matrices wurde die Trockensäulenchromatographie verwendet. Wie gezeigt werden konnte, lassen sich die Bedingungen der Dünnschichtchromatographie (DSC) auf silanisiertem Silikagel mit Isopropylether-Tetrahydrofuran-Salpetersäure (65203) auf das genannte Verfahren übertragen. Chromatogramme sind daher auf trocken geschichteten Säulen mit Lösungsmittelsystemen der DSC herstellbar. Uran wird eluiert und mit Arsenazo III spektrophotometrisch bestimmt. Das Verfahren wurde zur Uranbestimmung in Monazit und Phosphorit erfolgreich angewendet.

     

The chromatography of metals on DEAE-cellulose layers in phosphoric acid media

The adsorption behaviour of forty-eight metals on DEAE-cellulose thin layers has been examined in aqueous phosphoric acid media. R_F values are given as a function of phosphoric acid concentration over the range 0.01–1.0 M and are compared with those obtained in a similar manner with a crystalline cellulose, Avicel SF. Particularly strong retention on DEAE-cellulose occurred for Mo(VI), W(VI), Re(VII), the platinum group metals, Au(III) and Bi(III). Weak to moderate retention was also observed for several metals, such as V(V), Fe(III), Se(IV), In(III), the rare earths and U(VI), at lower concentrations of phosphoric acid (<0.1 M).     

The influence of couple-stresses on singular stress concentrations in elastic solids

Zusammenfassung Es werden im Rahmen einer linearisierten Theorie, welche Spannungsmomente berücksichtigt, singuläre Spannungskonzentrationen untersucht. Zu diesem Zweck wird mit Hilfe der exponentiellen Fouriertransformation für das Problem der Halbebene unter verteilter Oberflächenbelastung im ebenen Verschiebungszustand eine exakte Lösung aufgestellt. Diese Lösung wird anschliessend zum Studium des singulären Spannungsfeldes benützt, welches sich unter konzentrierter Normal-oder Tangentiallast sowie unter unstetiger Schubbelastung einstellt; sie wird auch zur Ermittlung der Spannungskonzentration benützt, welche von einem flachen Stempel herrührt. In jedem Falle werden die erhaltenen Singularitäten im einzelnen studiert und mit den entsprechenden Singularitäten der klassischen Elastizitätstheorie verglichen.

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This paper was prepared under Contral Nonr-220 (58) with the Office of Naval Research in Washington, D. C.

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The work underlying this paper was carried out in part while the second author was a Guggenheim Fellow at Keio University, where he held a Visiting Professorship.