Elektrochemische Untersuchungen an Organothallium(III)-Verbindungen

The electrochemical reduction of dialkylthallium(III) cations in aqueus buffer solutions and dimethylformamide yields by the first electron transfer the instable intermediate {R₂Tl}, which in dependence of the reaction conditions is electrochemical reduced to Tl° or disproportionates to R₃Tl and Tl°. Phenyl-substituted organothallium compounds are reduced to Tl° and (C₆H₅)₂Hg in one step.     

Polarographische Untersuchungen an Thallium(I)—Äthan-1,2-dithiolkomplexen

Complexation of thallium(I) with ethane-1,2-dithiol has been studied polarographically in 25% ethanol, 0.5M-NaClO₄, 0.01M-HClO₄ and 0.002% Triton X-100. Thallium in presence of ethane-1,2-dithiol, reduces reversibly at d.m.e. and the plateau current is diffusion-controlled. The successive formation of two complexes, 1∶1 and 1∶2, is indicated byDeford andHume's method. The overall changes in the thermodynamic parameters viz. ΔG, ΔH, ΔS accompanying complexation reactions have also been reported.     

Untersuchungen zur Struktur von Thallium(I)-halogenomercuraten(II)

Investigations on the Structure of Thallium(I) Halide Mercurates(II) Tl₄HgBr₆ crystallizes tetragonal with a = 8.978, c = 8.812 Å and Z = 2 in the space group P4/mnc. Singlecrystal methods revealed isolated HgBr₆-octahedra, compressed alonged the [001] axis, with thallium atoms between them. The results have been extended to clarify the structures of the isomorphous compounds (NH₄)₄HgBr₆ (a = 9.011, c = 8.660 Å), Tl₄HgJ₆ (a = 9.529, c = 9.387 Å) and Tl₄HgCl₂Br₄ (a = 8.896, c = 8.735 Å). It was impossible to obtain Tl₄HgCl₆; all attempts resulted in the formation of Tl₁₀Hg₃Cl₁₆, which crystallizes tetragonal (a = 8.477, c = 23.699 Å).     

Einschiebungsreaktionen in die Organothallium(III)-Element-Bindung

Insertion Reactions to the Organothallium (III)-Element Bond Insertion reactions to the thallium-element bonds of Me₂Tl-NMe₂ and Me₂TI-OEt with RNCS, PhNCO, CS₂. COS, CO₂, SO₂ and SO₃ and the characterization of the reaction products with the chemical and spectroscopic methods are reported.     

Thallium(III)

Ohne Zusammenfassung     

Untersuchungen an Tetrachloroferraten(III)

Information on physical and chemical properties, especially on the structure and chemical bonding of M[FeCl₄]-complexes has been obtained by measurements of the optical absorption, the MÖSSBAUER effect and EPR. (M stands for a monovalent cation.) The iron(III) chlorocomplex compounds Ag[FeCl₄], Rb[FeCl₄] and Li[FeCl₄] have been proved to exist within the systems MCl? FeCl₃ by measurements of optical spectra and EPR.     

Thermal Decomposition of Thallium(I) Bis-oxalatodiaquaindate(III) Monohydrate

Thallium(I) bis-oxalatodiaquaindate(III) monohydrate was obtained by precipitation of indium(III) withoxalic acid from slightly acidic solution in the presence of thallium(I). The complex was subjected to chemical analysis. The thermal decomposition behavior of the complex was studied using TG, DTA and DTG techniques. The solid complex salt and the intermediate product of its thermal decomposition were characterized using IR absorption and X-ray diffraction spectra. Based on data from these physicochemical investigations the structural formula of the complex was proposed as Tl[In (C₂O₄)₂ (H₂O)₂]⋅H₂O. This revised version was published online in August 2006 with corrections to the Cover Date.     

Polarographische Studien an Uran(VI)-Verbindungen. I

Zusammenfassung Die polarographische Reduktion von Uran(VI) in schwefelsaurer Lösung an der Quecksilbertropfelektrode wurde untersucht und eine square-wave-polarographische Bestimmungsmethode ausgearbeitet, mit der noch 7·10^–7 Mol Uran/l in Gegenwart 20 anderer Metallionen gut reproduzierbar bestimmt werden können.

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Polarographic studies on uranium(vi) compounds, i

Summary The reduction of uranium(VI) in sulphuric acid solutions has been studied polarographically at the dropping mercury electrode and a square wave polarographic method for the determination up to 7·10^–7 M uranium in presence of 20 other metals is described.

     

Thallium(I)

Ohne Zusammenfassung     

Thallium(I)

Ohne Zusammenfassung     

Arylvanadium(III)-Verbindungen. VII. Organovanadium(III)-Verbindungen vom Typ LiVMes3(ERn) und ihr Oxydationsverhalten

Arylvanadium(III) Compounds. VII. Organyl Vanadates of the Type LiVMes₃(ER_n) and their Oxidation Trimesityl vanadium yields with carbyl ligands lithium trimesityl organyl vanadates. It reacts also with LiER_n (E ? Si, Sn, N, P, O) forming complexes of the type LiVMes₃(ER_n). The oxidation behaviour of the amido compounds are investigated, and VMes₃(NPh₂) is synthesized. The compounds are characterized by their magnetical, spectral, and thermal properties.     

Thallium(III) coordination compounds: chemical information from 205Tl NMR longitudinal relaxation times

²⁰⁵Tl longitudinal relaxation rate measurements were performed on several thallium(III) complexes with the composition Tl(OH)_n(H₂O)_6?n^(3?n)+ (n = 1,2), Tl(Cl)_n(H₂O)_m?n^(3?n)+, Tl(Br)_n(H₂O)_m?n^(3?n)+ (m = 6 for n = 1–2, m = 5 for n = 3, m = 4 for n = 4), Tl(CN)_n(H₂O)_m?n^(3?n)+ (m = 6 for n = 1–2, m = 4 for n = 3–4) in aqueous solution, at different magnetic fields and temperatures. ¹³C and ²D isotopic labelling and ¹H decoupling experiments showed that the contribution of the dipolar relaxation path is negligible. The less symmetric lower complexes (n < 4) had faster relaxation rate dominantly via chemical shift anisotropy contribution which depended on the applied magnetic field: T₁ values are between 20 and 100 ms at 9.4 T and the shift anisotropy is Δσ = 1000–2000 ppm. The tetrahedral complexes, n = 4, relax slower; their T₁ is longer than 1 s and the spin–rotation mechanism is probably the dominant relaxation path as showed by a temperature dependence study. In the case of the TlCl₄^? complex, presumably a trace amount of TlCl₅^2? causes a large CSA contribution, 300 ppm. Since the geometry and the bond length for the complexes in solution are known from EXAFS data, it was possible to establish a correlation between the CSA parameter and the symmetry of the complexes. The relaxation behaviour of the Tl–bromo complexes is not in accordance with any known relaxation mechanism. Copyright © 2002 John Wiley & Sons, Ltd.     

Neue Kupfer(I,II)-Verbindungen

New Copper(I, II) Compounds Complexes of the type [Cu^II(N∩N)₂][Cu^ICl_1+x]_2x (N∩N = en, pn, 2-amino picoline) are prepared from Cu(N∩N)₂Cl₂ and copper(I) chloride. [Cu^II(enac)][Cu^ICl₂]₂ — a complex with a macrocyclic cation — is obtained, by the reaction of Cuen₂Cl₂ in aqueous acetone. Diacetyl monoxime partially reduces copper(II) of Cu(NSMe)₂Cl₂ and in this way causes the formation of [Cu(NSMe)_2][CuCl₃] (NSMe = β-aminoethyl methylsulfide). On the other hand a template reaction of this oxime with Cu(NSMe)₂ (ClO₄)₂ produces Cu^II(ONNSMe)(ClO₄) (HONNSMe?CH₃C(NOH)C(NCH₂CH₂SCH₃)CH₃), which shows a reduced paramagnetism. Basing on magnetic behaviour, i. r. and vis spectra the structure of the new compounds is discussed.     

Thermogravimetrische Untersuchungen an zeolithischen Erdalkalithioferraten(III)

The degradation of the hydrates of the alkaline earth thioferratesM(FeS₂)₂·xH₂O,M=Ca, Sr, Ba, resulting from ion exchange on KFeS₂, is studied by TG and by X-ray diffraction analysis. The zeolitic character of the very loosely bound water in these compounds is proved. There exist several cristallographically distinct phases as a function of the water content.

Herrn Prof. Dr.O. Hoffmann-Ostenhof zum 65. Geburtstag gewidmet.     

Polarographische Untersuchungen an N-Nitrosodimethylanilin(I)

Ohne Zusammenfassung     

Solid Membranes of Copper Hriacyanoferrats (III) as Thallium (I) Sensitive Electrode

Abstract

Solid membranes of copper hexacyanoferrate (III) in Areldite are evaluated as thallium (I) sensitive electrode. The membrane electrode gave a linear near Normstian response to thallium (I) ions in the concentration range 10^?1 - 5 × 10^?4 M and can be used to estimate T1 (I) down to 10^?4 M. The responses of the electrode is fast and steady potentials are obtained in less than a minute. The same membrane has been used over a period of six months without any appreciable drift in potential. The electrode can also be used satisfactory in partially non-aqueous media and in presence of a number of interfering ions. It is superior to the existing T1(I) solid membrane electrodes as it can function in alkaline range also.