Use of organic reagents in inorganic analysis

Summary Thorium and zirconium have been determined gravimetrically with phenylglycine-p-carboxylic acid and zirconium alone with phenylglycine-o-carboxylic acid, almost within the same pH range. Better results are obtained when zirconium is precipitated in acetic acid solution in presence of a little ammonium acetate. A number of foreign ions may be separated from thorium and zirconium with these reagents. Iron and titanium cause heavy interference. The interference caused by iron, may however, be eliminated by adding a little ascorbic acid, before precipitation of the metals. The para acid can also extract thorium from a mixture of cerite earths and from monazite sands.Part V: See Z. anal. Chem. 158, 347 (1957).The author likes to thank Dr. B. N. Bose, Principal of the College and Dr. S. K. Sinha, the Head of the Department of Chemistry for their kind advice and encouragements.     

Separations involving sulphides

Summary It has been shown that it is possible to separate and estimate quantitatively platinum, rhenium, gold or pentavalent antimony from zirconium by decomposing the thiosalts, formed by these elements with 2 N sodium sulphide reagent, with hydrochloric acid.Part I: Salaria, G. B. S.: Z. analyt. Chem. 179, 91 (1961).     

Die Trennung des Rhodiums von Platin, Palladium und Iridium durch Ionenaustausch

Ohne Zusammenfassung1 Vgl. Berg, E. W., und W. L. Senn: analyt. Chemistry 27, 1255 (1955); vgl. diese Z. 150, 380 (1956); Cluett, M. L., S. S. Berman und W. A. E. McBryde: Analyst 80, 204 (1955); vgl. diese Z. 150, 380 (1956).     

Solochrome Black P.V. as a new reagent in chelatometry

Summary Solochrome Black P.V. has proved to be a suitable metallochromic indicator in direct titrations of Mg, Zn, Cd and Mn^II with EDTA or in back titrating Pb, M and Co at p_H 10. By its aid together with the application of masking agents as potassium cyanide and ammonium fluoride and the mercuric nitrate procedure, fifteen binary mixtures were analysed using simple procedures which gave precise, reproducible and highly accurate results. It can be used as a substitute for Eriochrome Black T in determining micro and milligram amounts of the above mentioned cations.Part I: Khalifa, H., and S. W. Bishra: Z. analyt. Chem. 183, 108 (1961).     

Die colorimetrische Bestimmung von Zirkonium mit Arsenazo III(I)

Ohne Zusammenfassung Sävvin, S. B., u.V. B. Bagreev: Zavodskaja Laborat.26, 412 (1960); vgl. diese Z.186, 318 (1962).     

The acid-base properties of solochrome violet R. S.

Summary The acid base properties of solochrome violet R.S. has been studied with the object of testing its use as an acid base indicator or as a colorimetric reagent. The pk values of 4.35, 7.4, and 9.45 corresponding to the three steps of ionisation of the free acid were evaluated by the aid of the relation between log (acid)/(salt) and ph values obtained during the course of the potentiometric titration of the free acid with a free base. The dye has proved to be a suitable indicator in titrating some mineral and organic acids as well as a colorimetric reagent for the microdetermination of vanadium.     

Synthesen in der Aderminreihe, 4. Mitt.: Versuche zum Mechanismus der Cystein- und Tryptophan-Biosynthese

Zusammenfassung Die nichtenzymatische Reaktion von Schwefelwasserstoff (Indol),l-Serin und Pyridoxal führt zudl-Cystin (dl-Tryptophan). Dieser sterische Ablauf ist am einfachsten mit einem Reaktionsweg über Pyridoxyliden-aminoacrylsäure zu deuten. -Eliminierungen anSchiffschen Basen von -Hydroxy--Dialkylamino- und -Äthylthio-alaninestern werden untersucht. In Gegenwart stark basischer Ionenaustauscher wird aus Salicyliden-S-äthhylcystein-äthylester (3) Äthylmercaptan eliminiert. An die gebildete Acrylsäure addiert sich ein weiteres Mol3 zu4.

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Syntheses in the adermine series, IV: Experiments concerning the mechanism of the cysteine and tryptophan biosynthesis

The steric course of the non-enzymatic reaction of hydrogen sulfide (indole),l-serine and pyridoxal todl-cystine (dl-tryptophan) has been studied. The results point to pyridoxylidene aminoacrylic acid as an intermediate. -Eliminations with Schiff bases of -hydroxy-, -dialkylamino-, and -ethylthio-alanine esters have been investigated. In the presence of strongly basic ion exchangers ethyl mercaptan is eliminated from ethyl-N-salicylidene-S-ethyl cysteinate (3). A second mole of3 adds to the acrylic acid thus formed to yield4.

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Herrn Prof. Dr.E. Broda zum 60. Geburtstag freundschaftlich gewidmet.

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3. Mitt.:U. Schmidt undG. Giesselmann, Ann. Chem.657, 162 (1962).     

Die chemische Analyse durch Hochfreqnenzmethoden

Ohne Zusammenfassung Blaedel, W. J., T. S. Burkhalter, D. G. Flom, G. Hare und F. W. Jensen: Analyt. Chemistry : 4, 198 (1952). Digest of round-table discussion at 119. Meeting, Amer. Chem. Soc., Div. of Anal. Chem., Cleveland, Ohio.     

Bei der papierchromatographischen Trennung von Dinitrophenylderivaten der Diaminopimelins?ure

Ohne Zusammenfassung Blackburn, S., and A. G. Lowther: Biochemic. J. 48, 126 (1951).     

Zur Kenntnis der Netzhautstoffe III

Ohne Zusammenfassung1. Mitteilung:Brunner, Baroni undKleinau, Hoppe-Seylers Z. physiol. Chem.236 (1935) 257; 2. Mitteilung:Brunner u.Kleinau, Mh. f. Chem.68 (1936) 244, bzw. S.-B. Akad. Wiss. Wien IIb 5 (1936) 464.Die vorliegende Arbeit wurde seitens der Akademie der Wissenschaften in Wien durch eine Subvention aus den Mitteln der Zachstiftung gefördert. Wir gestatten uns auch an dieser Stelle unseren Dank hiefür auszusprechen.     

Complexes of metallochromic substances. IV

Summary The dissociation constants of proton complexes of 2-(o-carboxyphenylazo)-naphthionic acid and 2-(o-arsonophenylazo)-naphthionic acid were determined. The optimum conditions for the formation of complexes of these substances with Cu²⁺, and Ni²⁺ were found. The composition of the copper(II) complexes, also their formation and stability constants were estimated.

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Zusammenfassung Die Dissoziationskonstanten der Protonenkomplexe von 2-(o-Carboxyphenylazo)-naphthionsäure und 2-(o-Arsonophenylazo)-naphthionsäure werden ermittelt. Die optimalen Bildungsbedingungen für die Komplexe dieser Verbindungen mit Cu²⁺ und Ni²⁺ wurden bestimmt. Schließlich wurden auch die Zusammensetzung sowie die Bildungs- und Stabilitätskonstanten der Cu²⁺-Komplexe festgestellt.

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The author wishes to thank Miss L. Krumlová, and Miss D. Vrzalová for their technical assistance in the experimental work.

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Part III: See Z. analyt. Chem. 207, 178 (1965)     

Zu dem Verfahren zur Bestimmung von Largactil

Ohne Zusammenfassung Dubost, P., u. S. Pascal: Ann. pharmac. franç. 11, 615 (1953); vgl. diese. Z. 145, 452 (1955).     

Synthesis and amino acid extraction abilities of chiral calix[4]arene triamides containing amino alcohol units

Herein the synthesis and extraction abilities of new d-/l-phenylalaninol substituted p-tert-butylcalix[4]arene triamide derivatives (3 and 4) towards amino acids are reported. These compounds (3 and 4) have been easily synthesized via aminolysis of p-tert-butylcalix[4]arene trimethylester (2) with d-/l-phenylalaninol in methanol-toluen solvent system at one step. The extraction properties of the prepared chiral calix[4]arene triamide derivatives (3 and 4) towards some selected amino acid methylesters are studied by liquid–liquid extraction. Results show that these chiral calix[4]arene triamide derivatives (3 and 4) exhibited a good affinity towards all amino acid species without any remarkably discrimination.     

Volumetrische Bestimmungen mit Dead stop-Indikation. VI

Zusammenfassung Silberionen können mit einer Jodid-Maßlösung unter Verwendung der Dead stop-Indikation titriert werden. Das sprunghafte Anwachsen der Stromstärke wird durch das Jod bedingt, das aus dem Jodidüberschuß durch Kaliumdichromat freigesetzt wird. In Gegenwart von Quecksilberionen kann die Summe aus Quecksilberionen und Silberionen titriert werden. Die Menge an Quecksilberionen kann dann durch Titration mit Thiosulfationen bestimmt werden. Aus der Differenz der beiden Messungen ergibt sich der Gehalt an Silberionen. Die Methode eignet sich auch zur Analyse von Silberamalgamen.Vgl. dazu Kiss, S. A.: diese Z. 194, 104 (1963).Auf diesem Weg sei mein Dank meiner Mitarbeiterin Frau B. R. Doszpod ausgesprochen für die Hilfe, die sie bei der Durchführung der Messungen leistete.     

Derivate des Methylendioxybenzols, 28. Mitt.:

Zusammenfassung Es wird die Synthese der 2,5-Dimethoxy-3,4-methylendioxy- (1g), des 2,3-Dimethoxy-4,5-methylendioxy- (1h) und des 4,5-Dimethoxy-2,3-methylendioxy-phenols (1i) und ihrer Methyläther1j, k beschrieben. Weiterhin wird über die Darstellung des 2,3,6-Trimethoxy-4,5-methylendioxy-allylbenzols (1m) und die Synthese vondl-2-Amino-1-(dimethoxy-methylendioxyphenyl)-propan-Abkömmlingen (2d–f) berichtet.

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Derivatives of methylendioxy-benzene, XXVIII.: Reactions of the Dimethoxy-methylendioxy-benzaldehydes

Syntheses of 2.5-dimethoxy-3.4-methylenedioxy- (1g), 2.3-dimethoxy-4.5-methylenedioxy- (1h), and 4.5-dimethoxy-2.3-methylenedioxy-phenole (1i) and their methyl ethers1j, k and the preparation of 2.3.6-trimethoxy-4.5-methylenedioxy-allylbenzene (1m) and ofdl-2-amino-1-(dimethoxy-methylene-dioxyphenyl)-propane derivatives are described.

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Mitt.:F. Dallacker, Chem. Ber., im Druck.     

Computer estimation of dissociation constants. Part IV. Precision and accuracy of potentiometric determinations

The protonation constants logK _Hj of the acidH _J are determined by regression analysis of potentiometric titration data whencommon parameters (logK _Hj,j = 1,...,J) andgroup parameters (E ⁰,L ₀,H _T ) are refined. Two kinds of systematic error have been investigated: the error from an uncertainty of group parameters and the error from a computational strategy of the minimization algorithm used. An analysis of variance of logK _Hj matrix was made for 6 reproduced titrations and 7 computational strategies of 6 various regression programs. It was concluded that the influence of the program used is negligible. From two ways of calibration of the glass electrode cell,the internal calibration (performed during titration) was slightly more accurate thanthe external calibration (done separately). Of programs tested, the ESAB and ACBA are most powerful because they permit refinement of group parameters and internal calibration. D-tartaric acid was chosen as model substance.Previous Part III.: Iraqi J. Sci.1981,22, 67.     

Oxidations with potassium permanganate in the presence of fluoride

Summary The titration of ferrous iron in presence of fluoride ions in acid medium gives fleeting end points and erroneous results. A method is deviced to overcome this difficulty by oxidising the ferrous with an excess of KMnO₄ in alkaline medium. After mixing the reactants the excess of KMnO₄ is reduced by an excess of Hg₂ ²⁺ ions in presence of H₂SO₄ and fluoride. The remaining mercurous is then titrated with standard KMnO₄ solution.Part III: Issa, I. M., and M. Hamdy: Z. analyt. Chem. 174, 418 (1960).     

Enantiomeric Recognition of d- and l-Amino Acid Methyl Ester Hydrochlorides by New Chiral Bis-pyridino-18-crown-6 Substituted with Urea, and Diphenyl Groups

The article reports the synthesis and chiral recognition properties of a new chiral bis-pyridino-18-crown-6 (7), having urea, diphenyl, and allyloxy groups. The chiral bis-pyridino-18-crown-6 was prepared by a thirteen-steps procedure from the commercially available (S)-(+)-mandelic acid and chelidamic acid. The association constants (K _a) (1.33 × 10³–3.20 × 10³) for enantiomeric recognition of d- and l-amino acid methyl ester hydrochlorides using the chiral bis-pyridino-18-crown-6 have been examined by ¹H-NMR titration method in CDCl₃ at 25 °C. The chiral bis-pyridino-18-crown-6 showed higher association constants for the d-series amino acid methyl ester (d-AlaOMe, d-LeuOMe, d-MetOMe) hydrochlorides as compared to the corresponding l-series (l-AlaOMe, l-LeuOMe, l-MetOMe) hydrochlorides.