Gas-chromatographische Trennung isomerer aromatischer C6-C10-Kohlenwasserstoffe

Zusammenfassung Die Trennung der isomeren aromatischen C₆-C₁₀-Kohlenwasserstoffe gelingt an gepackten Säulen bei Verwendung einer Mischung aus Bentone 34, Siliconöl und Lanolin. Die Mengenverhältnisse der modifizierenden Zusätze sind von entscheidender Bedeutung und können zur Erzielung einer gleichbleibenden Trennleistung nur in sehr engen Grenzen variiert werden. Relative Retentionszeiten und Chromatogramme werden für 2 Säulentypen angegeben (Säule 16% Bentone 34; 2,5% Lanolin; 1,5% Siliconöl. Säule 210% Siliconöl; 5% Bentone 34; 4% Lanolin).

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Separation of isomeric C₆ to C₁₀ aromatic hydrocarbons by gas chromatography

Separation of isomeric aromatic hydrocarbons from each other has been obtained using packed columns and Bentone 34 modified with silicone oil and lanolin. For maximum resolution the proportions of the modifying agents are very important. Retention data and chromatograms of two different column types are given (column 16% Bentone 34; 2,5% lanolin; 1,5% silicone oil. Column 210% silicone oil; 5% bentone 34; 4% lanolin)

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Herrn Priv.-Doz. Dr. H. W. Nürnberg danke ich für wertvolle Diskussionsbemerkungen. Für die gewissenhafte Aufnahme der Gas-Chromatogramme und die Herstellung zahlreicher Trennsäulen sei Frau O. von Mylius auch an dieser Stelle herzlich gedankt.     

Polymeric membrane sodium-selective electrodes based on calix[4]arene ionophores

Six kinds of tetra alkylester type calix[4]arene derivatives, (R₁=R₂=CH₃1, C₂H₅2, C₃H₇3,n-C₄H₉4,t-C₄H₉5,n-C₁₀H₂₁6), a diethyl-didecyl mixed ester type (R₁=C₂H₅, R₂ =C₁₀H₂₁7), and three kinds of lower rim bridged types (R₁=C₂H₅, R₂–R₂=(CH₂)₁₀8, (CH₂)₁₂9, (CH₂)₂(OCH₂CH₂)₃10) were characterized by electrochemical measurement to elucidate the effect of the length of the alkyl group of alkoxycarbonyl substituents on Na⁺ selectivity. To obtain excellent Na⁺ selective ionophores, introduction of short chain alkyl groups rather than long chain ones, such as a decyl group, and maintenance of sufficient solubility of the calix[4]arene derivatives in the membrane solvent are required concurrently. Among the calix[4]arenes tested, 25,26,27,28-tetrakis[(ethoxycarbonyl)methoxy]-p-tert-butylcalix[4]arene2, and the diethyl-didecyl mixed ester type derivative7 are the best ionophores for a Na⁺ selective electrode. On the other hand, sodium selectivity of the bridged type derivative9 is comparable or even superior to that of the known bis(12-crown-4).This paper is dedicated to the commemorative issue on the 50th anniversary of calixarenes.     

Schiff base complexes of dioxouranium(VI), III. Commun.: Dioxouranium(VI) complexes of bibasic tetradentateSchiff bases

Bibasic tetradentateSchiff bases having the donor system OH–NX–NX–OH have been shown to form UO₂(NO₃)₂(SBH₂) type of derivatives [SBH₂ is the molecule of the bibasic tetradentateSchiff bases such as HOC₆H₄C(R) N(CH₂) _n NC(R)C₆H₄OH (where R=H or CH₃ andn=2 or 3) and HOC(R)CHC(CH₃)N(CH₂) _n NC(CH₃)CH C(R)OH (where R=CH₃ or C₆H₅ andn=2 or 3)]. The 11 stoichiometry of these complexes is shown by elemental analysis and conductometric titrations. The molar conductence values in nitrobenzene indicate the non-electrolytic behaviour and the magnetic susceptibility measurements by the Gouy method show these complexes to be diamagnetic.With 1 Figure     

Thiolactame als Reagenzien in der quantitativen Analyse. IX

Zusammenfassung Thiocaprolactam (T) eignet sich zur Goldbestimmung im Konzentrationsbereich 10 bis 130 g Au/ml mit einem Fehler von ±0,5g. Thiocaprolactam bildet mit [AuCl₄]^– eine Verbindung im molaren Verhältnis TAuCl=112, mit [AuJ₄]^– im molaren Verhältnis TAuJ=213. Dagegen bilden sich im System T:Au:Br zwei verschiedene Verbindungen: Ein Bromidkomplex mit höherem Goldgehalt TAu=12, der mit Chloroform extrahierbar ist, und eine sich als Niederschlag ausscheidende Verbindung mit dem Verhältnis TAuBr=112.

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Thiolactams as reagents in quantitative analysis. IX

Summary Thiocaprolactam (T) is suitable for the determination of gold in the concentration range 10–130g Au/ml with an error of ±0.5g. Thiocaprolactam yields with [AuCl₄]^– a compound in the molar ratio TAuCl=112, with [Aul₄]^– in the molar ratio TAuI=213. On the other hand various compounds result in the system TAu Br. The molar ratio in the case of the bromide complex has a higher gold content, namely TAu=12; this product is extractable with chloroform and a compound that comes down as a precipitate shows the ratioT Au Br=112.

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Herrn Dr.K. Czerepko möchte ich hiermit meinen Dank für die Diskussion der Ergebnisse aussprechen.     

Quantitative electron-probe microanalysis of light elements: Determination ofa-Si∶C∶N∶O∶H insulating films

Amorphous SiCNOH films (1–3 m) are studied by EPMA after deposition of gold (1–5 nm) as a conductive coating. Its influence on thek-ratios (X-ray intensity relative to an uncoated standard) of silicon, carbon, nitrogen and oxygen is described as a linear function of the simultaneously determinedk-ratio of gold. Thek-ratios representing the uncoated specimen are obtained by extrapolation and, in combination with the PAP matrix correction model, quantitative EPMA can be performed with an analytical error of 2–5%, as it is demonstrated by samples of SiC, Si₃N₄ and SiO₂. No systematic shift of the concentrations is observed for layers ofa-SiCNOH determined at various electron energies of 5–12.5 keV. Hydrogen is calculated by difference and the concentrations prove to be a useful estimate in agreement with the results of chemical analysis. Si-K/Si-K spectra recorded on organo-silicon films and binary silicon compounds point out significant differences concerning the formation of Si-C, Si-N and Si-O chemical bonds.     

Komplexe des Nickels mit p-Methylbenzamidoxim

Zusammenfassung Die Komplexbildung des p-Methylbenzamidoxims (pMB) mit Ni²⁺ wurde in neutraler und alkalischer Lösung spektrophotometrisch untersucht. In neutraler Lösung wird ein grüner Komplex 11 gebildet, dessen Bildungskonstante ₁=1,12 ist. In alkalischer Lösung werden zwei Komplexe (11 und 12) gebildet mit Bildungskonstanten ₁=4·10⁵ und ₂=0,2.

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Nickel complexes with p-methyl benzamide oxime

The complex formation of p-methyl benzamidoxime with Ni²⁺ was studied spectrophotometrically in neutral and in alkaline solution. A green complex 11 is formed in neutral solution. Its formation constant is ₁=1.12. In alkaline solution two complexes (11 and 12) are formed. Their formation constants are ₁=4·10⁵ and ₂=0,2 resp.

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Mit 6 Abbildungen     

Phosphorus-containing podands. 6. Calorimetric study of complexation of 1,17-bis (diphenylphosphinyl)-3,6,9,12,15-pentaoxaheptadecane with alkali and alkaline-earth metal salts in acetonitrile

1, 17-bis-(Diphenylphosphinyl-3, 6, 9, 12, 15-pentaoxaheptadecane in MeCN forms complexes of 11 and 12 composition (ML) with alkali and alkaline-earth metal salts, complexes of 11 and 21 composition were found for Li salts. The BaL²⁺ complex is the most stable complex, and the complexes NH₄L⁺ and CaL2+ are the least stable. The selectivity for Li is significantly higher for the podand studied than for crown ethers.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 575–581, March, 1991.     

Photometrische Bestimmung von Zirkoniumoxidchlorid in Speisesalz

Zusammenfassung 2-Chinolylfluoron bildet mit Zirkonium einen 14-Komplex, dessen Extinktionskoeffizient bei 539 nm _max=165000 ist. Das Bestimmungsverfahren für ZrOCl₂ in Speisesalz wird auf dieser Farbreaktion aufgebaut.

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Photometric determination of ZrOCl₂ in table salt

2-Quinolylfluorone forms a 14-complex with zirconium. Owing to its high extinction coefficient _max=165000 at =539 nm the complex can be used for the determination of ZrOCl₂ in table salt.

     

Einige analytische Eigenschaften von 1,3-Dimethyl-4,5-diaminouracil

Zusammenfassung 1,3-Dimethyl-4,5-diaminouracil (DAL) hat sich als sehr empfindliches Reagens zum selektiven Nachweis von Co²⁺-Ionen im stark alkalischen Medium einer Phosphatpufferlösung (p_H=11,20) erwiesen. Es wurden vier Additionsverbindungen von DAL mit den Zentralatomen Cd(II), Pd(II), Ni(II) und Co(II) im Verhältnis Me DAL=1 2 hergestellt. Spektrophotometrische Untersuchungen weisen darauf hin, daß bei p_H 6 bis 7 eine Komplexverbindung im Verhältnis CoDAL=12 gebildet wird.

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Summary 1,3-dimethyl-4,5-diaminouracil (DAL) has been found to be a very sensitive reagent for the selective detection of Co²⁺ ions in strong alkaline medium of a phosphate buffer solution (p_H=11.20). Four addition compounds of DAL with the central atoms Cd(II), Pd(II), Ni(II) and Co(II) with the ratio MeDal=12 have been prepared. Spectrophotometric studies indicate that at p_H=6–7, complex compound is produced with the ratio CoDAL=12.

     

Composition of 2-(3,5-dibromo-2-pyridylazo) diethylaminophenol chelates by liquid chromatography

Summary The composition of 3,5-diBr-PADAP metal chelates was determined by liquid chromatography employing appropriate eluents and non-polar bonded stationary phase. The metal-to-ligand ratios were 12, 12 and 12 for Cu(II), Co(III) and Cr(III) respectively, and the V(V)-to-ligand ratio found to be 111 in V(V)-3,5-diBr-PADAP-H₂O₂ in the presence of H₂O₂. The results are in agreement with literature data.     

Fixation and reduction of molecular nitrogen by [WH4(PC2H5Ph2)4] and [WH4(PCH3Ph2)4] in a γ-radiation field

Hydride complexes of W(IV) with dpep (diphenylethylphosphine) and dpmp (diphenylmethylphosphine) were irradiated in thf+C₆H₁₂(11) solutions, saturated with N₂+H₂(13). Radiation yields of hydrazine, ammonia and amines were evaluated. The mechanism of reduction of molecular nitrogen is discussed.     

Reduction of dialkoxydihydrofurans,dialkoxytetrahydrofurans, dialkoxydihydropyrans,and dialkoxytetrahydropyrans with LiAlH4 AlCl3 complex

The reduction of 2,5-dimethoxytetrahydrofurans, 2,5-dimethoxydihydrofurans, 2,6-dialkoxytetrahydropyrans, and 2,6-dialkoxydihydropyrans with mixtures of LiAlH₄ and AlCl₃ with various component ratios (31, 11, and 13) proceeds with ring opening and the formation of aliphatic -alkoxy alcohols. Hydrogenolysis of 2,5-dimethoxy-2,5-dihydrofuran and 2,6-dialkoxy-³-dihydropyrans is accompanied by a partial reduction of the double bond and the formation of unsaturated alkoxy alcohols and their saturated analogs. A possible mechanism for the hydrogenolysis is discussed.Translated from Khimiya, Geterotsiklicheskikh Soedinenii, No. 6, pp. 743–747, June, 1972.     

Some effective solvents for rapid and reliable characterization of phenylthiohydantoin-amino acids

Summary One-dimensional chromatography with internal standards permits reliable identification of the phenylthiohydantoins from all the common amino acids with the following TLC systems: silica gel — chloroform/n-butyl acetate (9010), di-isopropylether/ethanol (955), dichloromethane/ethanol/acetic acid (9082) ortrans-dichloroethylene/ethanol/acetic acid (88102); and cellulose with 25% formic acid — heptane/isobutanol/75% fromic acid (40309) or silica gel — chloroform/ ethanol/acetic acid/water (50470.52.5).Abbreviations: PTH=phenylthiohydantoin, TLC=thin-layer chromatography, HPTLC=high-performance TLC; other abbreviations: see end of text. Proportions in solvent mixtures are v/v except where otherwise indicated.     

Studies on mixed ligand complexes involving ligands of biological importance [Ni(II), Zn(II) or Cd(II)-1,10-phenanthroline — or 2,2′-bipyridyl-histidine]

The formation of mixed ligand complexes of the title metal ions with 1,10-phenanthroline (Phen) or 2,2-bipyridyl (Bipy) in presence of histidine (His) has been studied pH-metrically. The stepwise formation of 111 mixed ligand complexes has been inferred from the potentiometric titration curves. Initially, a 11 metal—Phen or—Bipy complex is formed in the lower buffer region and then the addition ofHis takes place resulting in 111 ternary complex formation. The formation constants (K _MAL ) of the resulting mixed ligand complexes have been calculated at 30±1°C (=0.1 KNO₃) and the values have been found to be higher than the formation constants of 12 and lower than those of 11 metal—His complexes. The order of stability in terms of metal ions follows the order, Ni(II)>Zn(II)>Cd(II).With 2 Figures     

Solvent extraction and spectrophotometric including graphite furnace atomic absorption determination of molybdenum in the environment

A selective and sensitive method for the extraction and microgram determination of molybdenum (VI) with hydroxamic acid as yellow molybdenum-hydroxamate complex from acidic medium is described. The molybdenum-PCPPSAHA complex has _max 388 nm, molar absorptivity 5.0 × 10³l mol^–1 cm^–1. The system obeys Beer's law in the range of 1–28 g/ml of molybdenum(VI). Sandell's sensitivity is 0.0192 g cm² and stoichiometry of the complex is 12, molybdenum: PCPPSAHA while mixed complex molybdenum-PCPPSAHA-morin has _max 400 nm and molar absorptivity 5.9 × 10³lmo1^–1 cm^–1 and stoichiometry of the complex is 121.The molybdenum is determined by graphite furnace atomic absorption spectrophotometry after directly pipetted the extract into the furnace which increases the sensitivity 20 fold.     

Spectrophotometric determination of indium using gallion

Summary The formation of violet coloured chelate of indium with Gallion has been studied. Indium forms only one chelate with Gallion at p_H 4.5 having _max 610 nm. The composition of the complex formed has been determined by various methods and is found to be 11 (MR). The values of stability constant have been calculated by three methods and the average value of logK obtained is 5.6 ± 0.1. A procedure for the spectrophotometric determination of indium has been suggested.

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Zusammenfassung Die Bildung eines violetten Chelates von Indium mit dem Reagens Gallion wurde studiert. In bildet damit ein einziges Chelat bei p_H=4,5 und _max=610 nm. Die Zusammensetzung des entstandenen Komplexes wurde nach verschiedenen Methoden ermittelt und gleich 11 (MetallReagens) gefunden. Die Stabilitätskonstante wurde nach drei Verfahren berechnet, wobei sich als Mittelwert logK=5,6±0,1 ergab. Eine Arbeitsvorschrift für die spektrophotometrische Bestimmung des In wird vorgeschlagen.

     

Formation of N-butane in the pyrolysis of ethylene [1]

Yields of n-C₄H₁₀ have been measured from the flow pyrolysis of C₂H₄ at 897 (±7) K. From 77 to 720 Torr the order of n-C₄H₁₀ formation was found to be 2.0±0.3 The rate constant for the reaction, was estimated to be 2.4(±0.6)×10^–4l mol^–1s^–1.

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-C₄H₁₀ C₂H₄ 897 (±7) . -C₄H₁₀ 77 720 2.0±0.3. 2C₂H₄C₂H₃+C₂H₅ 2,4 (±0,6)×10^{–4 –1–1}.

     

Nephelometric determination of germanium(IV) witho-phenanthroline and bromopyrogallol red in the presence of triton X-100

The light scattering of germanium(IV) witho-phenanthroline [phen] and bromopyrogallol red [BPR] in the presence of Triton X-100 has been studied. The ternary complex shows a constant light scattering intensity in an acidic medium (0.02 mol/l HCl+0.02 mol/l H₃PO₄). The maximum wavelength was 332 nm. The calibration graph is linear in the range 0.03–10 g/25 ml for Ge(IV). The detection limit is 0.03 g/25 ml. The composition of the ternary complex is GephenBPR = 122. The effects of diverse ions on the determination of Ge(IV) were examined. This simple method with high sensitivity can be successfully applied to the determination of Ge(IV) in coal fly ash, with a relative standard deviation of 2%.     

Copper(II)-disulphide interaction: a spectroscopic and electrochemical study of the interaction of copper(II) with an imidazole-containing disulphide

Summary The interaction of copper(II) salts with the imidazole-containing disulphide 5-(1,2,5-dithiazaepan-5-ylmethylene)-4-methyl-2-ethyl imidazole (MAMI) in MeOH have been investigated. The 11 Cu(ClO₄)₂MAMI system exhibited a single ligand field band at ca. 12200cm^-1, an intense shoulder at ca. 31500 cm^-1 and a less intense split feature at 24400 and 25300cm^-1 assignable to S() Cu^II and S() Cu^II charge transfer (CT) transitions, respectively. The e.p.r. parameters suggested the presence of a CuN₂SO chromophore, however; the 11 Cu(NO₃)₂MAMI system did not exhibit a S Cu^II CT band and the g value was comparatively high. An electrochemical study of the 11 Cu(ClO₄)₂MAMI system in MeOH revealed that the copper-disulphide interaction, though weaker, would confer a high redox potential as well as reversibility, similar to the copper-thioether interaction.     

New method of synthesizing 1,2,5-trisubstituted piperidine derivatives by reaction of 1,3-dienes with urotropin in the presence of palladium complexes

Conclusions It has been shown for the first time that 1-(2,7-octadienyl)-2,5-divinyl- and 1-(2,7-dimethyl-2,7-octadienyl)-2, 5-diisopropenylpiperidine can be prepared by reacting urotropin with butadiene or isoprene in the presence of a Pd(acac)₂-PR₃-A1(C₂H₅)₃-H₂SO₄ catalyst (1321.5).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1359–1363, June, 1977.