Iodophthalocyaninato(2–)thallium(III) – Synthese und Kristallstruktur

Iodophthalocyaninato(2–)thallium(III) – Synthesis and Crystal Structure Oxidation of dithalliumphthalocyaninate(2–) with excess iodine yields crystalline, blue-green iodophthalocyaninato(2–)thallium(III). It crystallizes in the orthorhombic space group Pnma (no. 62) with lattice parameters: a = 13.778(3) Å, b = 14.649(2) Å, c = 14.907(1) Å, Z = 4. The Tl atom coordinates four N_iso atoms (isoindole N atoms) and one I atom in a tetragonal pyramidal arrangement. The Tl atom is located out of the centre of the (N_iso)₄ plane towards the iodine atom by 0.959(3) Å. The Tl–I distance is 2.674(1) Å, the Tl–N_iso distances range from 2.20(1) to 2.23(1) Å (average 2.22(1) Å). The phthalocyaninate(2–) is severely distorted from planarity (concave distortion).     

Hydrogen Bonds at Silica – Polyvinylpyrrolidone – Water Interfaces

The effect of the adsorption of polyvinylpyrrolidone on the surface of highly dispersed silica on the state of interfacial water was studied by ¹H NMR spectroscopy and thermally stimulated depolarization with freezing out of the bulk water.     

Koordinationsambivalenz und elektronenstruktur ein- und zweikerniger methylcyclopentadienyldicarbonylmangan-komplexe der cyanpyridine und terephthalsäuredinitrile

The ambident cyanopyridine ligands form N(pyridine) and N′(nitrile) coordinated mono- and binuclear complexes with the (C₅H₄CH₃)(CO)₂Mn fragment. All three possible forms for 4-cyanopyridine could be isolated, whereas mononuclear compounds were obtained as most stable species in N¹-coordinated form with 3-cyanopyridine and in CN²-coordinated form with the 2-isomer. IR, NMR, and UV/VIS spectroscopy as well as electrochemistry and ESR spectroscopy of the anion radicals demonstrate superior π back-bonding via the pyridine nitrogen centers, the isolation of nitrile coordinated complexes is attributed to the kinetic stability of the CNMn bond. While terephthalonitrile was found to form exclusively mononuclear neutral complexes, its anion radical prefers to coordinate to a second metal fragment, illustrating the excellent coordination properties of reduced nitriles. A neutral binuclear complex could be isolated with the stronger π-acceptor, tetrafluoroterephthalonitrile.     

Polymethylmethacrylate und Mischpolymerisate von Methylmethacrylat und ?thylacrylat

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Phase Relationships in the U – Np – O System

U – Np – O phase equilibria was experimentally studied by X-ray diffraction in reducing and oxidizing conditions. Both (U1yNpy)O2 stoichiometric and hyper-stoichiometric compounds were characterized after a heating treatment and resulting lattice parameters were compared to that of previous studies. Synthesized stoichiometric compounds are monophasic and their lattice parameters as a function of Np content are in nice agreement with the Vegard's law between UO2 and NpO2 end-member. Resulting compounds after an oxidizing heat treatment of the stoichiometric samples confirm previous reported U – Np – O relationship. For low Np content, a biphasic hyper-stoichiometric compound is observed: a (U1-y’Npy’)O2+x phase (space group fm-3m) and a (U1-y”,Npy”)3O8 phase (space group C2 mm). For higher Np content (with starting material y = 0.7), only one monophasic hyper-stoichiometric phase (U1-y’Npy’)O2+x appears. Lattice parameters of the (U1-y”,Npy”)3O8 phase differ from the ones of pure U3O8, indicating some Np solubility in this compound. Although Np might remain tetravalent in the (U1y”,Npy”)3O8 phase, this result is in conflict with the assumption of Yamashita et al. (1994).     

Titrirmethode für Kupfer und Nickel und für Kupfer und Zink

Analytical and Bioanalytical Chemistry -     

Die Bestimmung von Oxyalkylengruppen in Glykolen und in Glykol- und Polyglykol?thern und -estern

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