Die Extraktion von Zink und Nickel mit tertiären aromatischen Aminen

Zusammenfassung Die Eignung einiger tertiärer aromatischer Amine zur Extraktion von Zink aus sauren und neutralen Lösungen wurde untersucht. Man kann diese Amine in drei Gruppen einteilen: solche mit gutem, solche mit schlechtem Extraktionsvermögen und solche, die zwar eine gute Extraktion vortäuschen, die aber tatsächlich als Maskierungsmittel wirken. Die Mehrzahl ist in die zweite Gruppe einzuordnen. In die dritte Gruppe gehören vor allem die Amine 3-(Benzylmethylamino)-propanol, N-Methyl-N-Propargyl-Benzylamin und N-Benzyl-N,N-Dimethyläthylendiamin. 3-(Dimethylamino)-Methylindol in schwach saurem Medium und N,N-Dimethylhomotryptamin im Neutralbereich können als gute Extraktionsmittel für Zink angesehen werden. Nickel wird von den meisten Aminen ganz oder teilweise maskiert.

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The extraction of zinc and nickel with tertiary aromatic amines

Summary A study has been made of the suitability of several tertiary aromatic amines for the extraction of zinc from acid and neutral solutions. These amines may be placed in three groups: those with good, those with poor extraction capabilities, and those which simulate a good extraction but in truth act as labelling agents. The majority should be placed in the second category. The third group includes above all the following amines: 3-(Benzylmethylamino)-propanol, N-methyl-N-propargyl-benzylamine and N-benzyl-N,N-dimethylethylenediamine. 3-(Dimethylamino)-methylindole in weakly acid medium and N, N-dimethylhomotryptamine in the neutral region can be looked upon as good extraction agents for zinc. Nickel is entirely or partially masked by most amines.

     

Fragmentierung von α,β-Epoxy-ketoximen zu Acetylenketonen. Vorläufige Mitteilung

A new version of the oxidoketone-alkynone fragmentation is described. Two steroidal α,β-oxido-oximes are shown to fragment to the corresponding alkynones when treated with hydroxylamine-O-sulfonic acid in alcaline solution at room temperature.     

Alkynylxenon(II) fluorides

Alkynylxenon(II) fluorides, RCC(triple bond)XeF, have been prepared from the reactions of the corresponding trimethyl(alkynyl)silanes, Me3(-)SiC(triple bond)CR, and XeF2 in the presence of [NMe4F in common organic solvents at low temperature. The existence of the linear unit C(triple bond)C-Xe-F was proved for PhC(triple bond)CXeF by the 19F-13C NMR correlation method using the HMBC pulse sequence.     

The Structure of Tetrakis(pentafluorophenyl)tellurium(IV), Te(C6F5)4

Tetrakis(pentafluorophenyl)tellurium(IV), Te(C₆F₅)₄, was prepared from the reaction of TeCl₄ and Mg(C₆F₅)Br. Crystallization of the crude product from n‐pentane at ?25 °C gave suitable single crystals. The title compound crystallizes in the monoclinic space group P2₁/c (Z = 8) with two independent molecules per unit cell.     

Strukturen von Bis(trifluormethyl)halogeno‐ und ‐thiocyanato‐mercuraten, [Hg(CF3)2X]— (X = Br,I, SCN), und ein Vergleich der Strukturparameter der CF3‐Gruppen

Structures of Bis(trifluoromethyl)halogeno and thiocyanato Mercurates, [Hg(CF₃)₂X]^— (X = Br, I, SCN), and a Comparison of the Structural Parameters of the CF₃ Groups [(18‐C‐6)K]₂[Hg(CF₃)₂SCN]₂ (1) and [P(CH₃)(C₆H₅)₃]₂[Hg(CF₃)₂X]₂ (X = Br (2) , I (3) ) are prepared and their crystal structures are determined. [(18‐C‐6)K]₂[Hg(CF₃)₂SCN]₂ (1) crystallizes in the monoclinic space group P2₁/c with Z = 2, [P(CH₃)(C₆H₅)₃]₂[Hg(CF₃)₂Br]₂ (2) in the monoclinic space group P2₁/n with Z = 2 and [P(CH₃)(C₆H₅)₃]₂[Hg(CF₃)₂I]₂ (3) in the triclinic space group P1¯ with Z = 1. In the solid state the three compounds form dimeric anions with planar Hg₂X₂ rings. The structural parameters of the Hg(CF₃)₂ units in the till now known bis(trifluoromethyl)halogeno mercurates are compared. In all compounds one nearly symmetric and one distorted CF₃ group exist. The largest differences of the C—F bond lengths is found for [(18‐C‐6)K][Hg(CF₃)₂I]. This can be regarded as the experimental evidence for the properties of trifluoromethyl mercury compounds to act as excellent difluorocarbene sources in the presence of alkali iodides.     

Resolving Sphingolipid Isomers Using Cryogenic Infrared Spectroscopy

1‐Deoxysphingolipids are a recently described class of sphingolipids that have been shown to be associated with several disease states including diabetic and hereditary neuropathy. The identification and characterization of 1‐deoxysphingolipids and their metabolites is therefore highly important. However, exact structure determination requires a combination of sophisticated analytical techniques due to the presence of various isomers, such as ketone/alkenol isomers, carbon–carbon double‐bond (C=C) isomers and hydroxylation regioisomers. Here we demonstrate that cryogenic gas‐phase infrared (IR) spectroscopy of ionized 1‐deoxysphingolipids enables the identification and differentiation of isomers by their unique spectroscopic fingerprints. In particular, C=C bond positions and stereochemical configurations can be distinguished by specific interactions between the charged amine and the double bond. The results demonstrate the power of gas‐phase IR spectroscopy to overcome the challenge of isomer resolution in conventional mass spectrometry and pave the way for deeper analysis of the lipidome.