Strukturanalyse organischer Sulfide mit Hilfe der Gras-Chromatographie

Zusammenfassung Eine Methode der Identifizierung von Alkyl- und Arylgruppen organischer Sulfide wurde ausgearbeitet, die die Spaltung dieser Stoffe mit Raney-Nickel zur gaschromatographischen Bestimmung der dabei entstandenen Kohlenwasserstoffe ausnützt.

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Summary A method was developed for identifying alkyl- and aryl groups of organic sulfides. The method employs the cleavage of these materials with Raney nickel for the gas chromatographic determination of the resulting hydrocarbons.

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Résumé On a mis au point une méthode d'identification des groupes alkylés et arylés des sulfures organiques exploitant la dissociation de ceux-ci par le nickel Raney pour le dosage par chromatographic en phase gazeuse des carbures d'hydrogène qui se forment.

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Die Autoren danken den Kollegen Dr.M. Veea, Ing.J. Petránek und Ing.J. Gaspari für die Überlassung von Proben organischer Sulfide.     

Ring transformation of 4-oxo-1,6,7,8-tetrahydro-4H-pyrido[1,2-a]-pyrimidine-3-carboxamide

The title compound /$\text{3}$/ may be transformed into the 3-/methylaminomethylene/--2,3,6,7,8,9-hexahydro-4H-pyrido[1,2-a]pyrimidine-2,4-dione /$\text{5}$E, $\text{5}$Z/ which is in equilibrium with the 1,2,3,6,7,8-hexahydro tautomer /$\text{8}$E, $\text{8}$Z/ in DMSO-d₆.     

Pulsating column separation and preconcentration of radioiodine on hydrophobic organic reagent loaded resilient open-cell polyurethane foam

The method is based on the resiliency of the open-cell polyurethane foam filling used in a pulsing bed column. A liquid anion exchanger containing I₂ has been used as a hydrophobic organic phase immobilized in the polyurethane foam matrix. Forced flow of the mobile phase during successive pulsing of the column bed results in high preconcentration factors with practically quantitative separation yields. The pulsated column technique may also be conveniently automated. It can be utilized most advantageously for the rapid determination of low activity radioiodine in environmental waters mainly in routine field analysis.     

Voltammetric determination of nitrate,perchlorate and iodide at a hanging electrolyte drop electrode

The use of a hanging electrolyte drop electrode is examined for the determination of nitrate, perchlorate and iodide. A three-electrode system was used with a polarographic analyzer. Crystal violet dicarbollylcobaltate(III) electrolyte in the nitrobenzene phase and magnesium sulphate in the aqueous phase with a Pb/PbSO₄ reference electrode made it possible to increase the viable potential range. For nitrate, the peak current/concentration relation was linear over the range 0–5 × 10^?5 M, and nitrate in potable water was easily determined.     

Sequential atomic absorption spectrometric determination of nitrate and nitrite in meats by liquid-liquid extraction in a flow-injection system

Sequential determinations of nitrate and nitrite based on continuous liquid-liquid extraction, and suitable for their routine determinations in meats, are reported. Nitrate reacts with bis(2,9-dimethyl-1,10-phenanthrolinato)copper(I) to form an ion-pair which is extrated into 4-methyl-2-pentanone in a flow-injection manifold. In one aliquot of sample, nitrite is oxidized by cerium(IV), so that total nitrate is determined. In another, nitrite is converted to nitrogen with sulfamic acid, so that only the original nitrate is determined. By measuring the atomic absorption signal of copper in the organic phase, mixtures of these anions can be determined at μg ml^?1 levels for nitrate/nitrite ratios from 10:1 to 1:10, with a sampling frequency of ca. 20 h^–1.     

The relationship between the structures of Cu(II) complexes and their chemical transformations: VII

The thermal decompositions of Cu(en)₂(NCS)X. where X^–=Cl^–, Br^–, NO ₃ ^– , BF ₄ ^– and ClO ₄ ^– , have been studied in comparison with the courses of Cu(en)₂(SCN)₂ and Cu(en)₂X₂ decomposition. It is shown that the presence of the thiocyanate group in the complexes Cu(en)₂(NCS)X is the most important factor in the decomposition course, in agreement with the fact that the anions X^– are not coordinated. or are only semicoordinated. Significant differences were found in the courses of thermal decomposition of two forms of Cu(en)₂(NCS)(BF₄) differing in the structure of their coordination polyhedra.

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Zusammenfassung Die thermische Zersetzung von Cu(en)₂(NCS)X (X=Cl Br, NO₃, BF₄ und ClO₄) wurde untersucht und mit der von Cu(en₂(SCN)₂ und Cu(en)₂X₂ verglichem. Der den Verlauf der Zersetzung entscheidend bestimmende Faktor isi die Anw esenheit der Thiocyanat-Gruppe in den Cu(en)₂(NCS)X-Komplexen, was in Übereinstimmung damit steht,. daß die Anionen X nicht oder nur teilweise koordiniert sind. Es wurden signifikante Unterschiedeim Verlauf der thermischen Zersetzung von zwei sich in der Struktur ihrer Kordinationspolyeder unter-, heidenden Formen von Cu(en)₂(NCS)(BF₄) gefunden.

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Cu(en)₂(NCS)X (X^–=Cl^–, Br^–, NO ₄ ^– , NO ₃ ^– , BF₄ ClO₄, Cu(en)₂(SCN)₂ Cu(en)₂(X)₂. , Cu(en)₂(NCS)X X Cu(en) (NCS)BF₄ i .

     

The effect of gamma radiation on biodegradability of morpholine in aqueous solution

The effect of -radiation on the aqueous solution of morpholine was studied on the basis of UV spectrum measurement, COD /chemical oxygen demand/, TOC /total organic carbon/ and STOD /short-term oxygen demand/ determination and Pitter's kinetic test of biodegradation. The biodegradability of the model solution after irradiation became substantially worse.     

Membrane extraction of pertechnetate with quaternary ammonium salts comparison with solvent extraction

The liquid membrane extraction (MX) and the solvent extraction (SX) of pertechnetate with Aliquat 336 as a carrier has been studied. From the results of SX the percentage of pertechnetate in the inner solution in experiment with LM was proposed. It has been found that the pertraction of pertechnetate depends on the inner solution used and the most effective solutions were those with ClO ₄ ^– and SCN^–. Effects of the carrier concentration in membranes and outer phase composition have been studied too. The results of these experiments were kinetic curves with a minimum, which may be interpreted as a result of competing processes in the systems.     

Thermal reactivities of potassium and cadmium hydrogenhexavanadates

The thermal reactivities of KHV₆O₁₆·3H₂O and Cd(HV₆O₁₆)₂·12H₂O were investigated. By means of IR spectroscopy and X-ray phase analysis it was found that, after dehydration, both compounds decompose to vanadium pentoxide and the corresponding metavanadate. Potassium metavanadate and vanadium pentoxide react together to form bronzes of different compositions. In contrast, vanadium pentoxide and cadmium metavanadate are the predominant components of the reaction products obtained within the temperature range from 300° to 800°C.     

Magnetic and spectral properties of the coligand isomer pair: Cu{N(CN)2}2(pyrazole)2 and Cu{pyrazole · N(CN)2}2

Summary New coligand isomers of composition Cu{N(CN)₂}₂(pz)₂ and Cu{pz · N(CN)₂}₂ (pz = pyrazole) were prepared and studied by measuring their magnetic susceptibilities up to 4.2K and by aid of their e.s.r., ligand field and i.r. spectra. The susceptibility data have been analysed with various models for the exchange-coupled copper(II) polymers. It is shown that the resultant exchange coupling is ferromagnetic for Cu{N(CN)₂}₂(pz)₂ (J 1.1 - 1.4 cm^–1) but antiferromagnetic for Cu{pz · N(CN)₂}₂ (J –0.4 cm^–1). A polymeric chain structure is proposed for Cu{N(CN)₂}₂(pz)₂ havingpseudo-octahedrally coordinated copper(II) and CN-bridging dicyanamide ligands. Its coligand isomer contains anionic chelate ligands, formed by nucleophilic addition between N(CN)₂ and pz in the copper(II) coordination sphere, and giving with this central atom a square-planar system. Definite, but slight axial interaction takes place between these structure units.