Materials Literature
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Electrospray mass spectroscopy has finally provided proof for the formation of oxomanganese(v) complexes such as 1 under the conditions of the Kochi-Jacobson-Katsuki epoxidation. Collision of 1 with olefins or sulfides in the gas phase regenerates the initial (salen)MNIII complexes by transfer of the oxygen atom.
${}^{55}\mathrm{Mn}$ NMR experiments were carried out at 1.3--4.2 K on six samples of lanthanum manganites, with a hole doping concentration ranging from the antiferromagnetic-insulator to the ferromagnetic-conductor region of the phase diagram. The dependence of the resonance frequencies on external fields is either…
This paper deals with molecular materials resulting from the chemical and electrochemical molecular assemblies of organic and inorganic precursors such as organic donors derived from TTF, organic nitronyl nitroxide radicals, decamethylferrocenium, metal bis(dithiolate), metal bis(dithiolene), polyoxometalates, and hex…
N-Acetylneuraminic acid (Neu5Ac) is the precursor of sialic acids, a group of important molecules in biological recognition systems. Biosynthesis of Neu5Ac is initiated and regulated by its key enzyme, UDP-N-acetylglucosamine 2-epimerase (UDP-GlcNAc 2-epimerase, EC 5.1. 3.14)/N-acetylmannosamine kinase (ManNAc kinase,…
The magnetotransport and magnetic properties of epitaxial ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$ thin films grown on (001)-oriented MgO substrates by pulsed-laser deposition have been investigated. The magnetoresistance (MR) exhibits a peak around the Verwey transition ${(T}_{\ensuremath{\nu}})$ as has also been reported…
The characteristic length scales of the structure and fractal behavior of a thixotropic colloidal suspension of synthetic clay were studied by using a combination of small-angle neutron and x-ray scattering and static light scattering. At the same time, macroscopic mechanical behavior at rest was characterized by mean…
We report on the magnetoresistive properties of all-oxide tunnel spin valves in which electrodes of mixed valence manganites (La 0.7 Sr 0.3 MnO 3 ) are separated by a thin insulating layer. The structures were prepared by Pulsed Laser Deposition and several tunnel barriers were used including PrBa 2 (CuGa) 3 O 7 , CeO…
(Ba,Sr)TiO3 (BST) thin films grown by chemical vapor deposition and with platinum (Pt) top and bottom electrodes have been characterized with respect to the leakage current as a function of temperature and applied voltage. The data can be interpreted via a thermionic emission model. The Schottky approximation accounts…
The temperature- and field-dependent permittivities of fiber-textured Ba0.7Sr0.3TiO3 thin films grown by liquid-source metalorganic chemical vapor deposition were investigated as a function of film thickness. These films display a nonlinear dielectric response under conditions representative of those encountered in dy…
Cyclic voltammetry (CV) has been performed on light‐emitting electrochemical cells (LECs) using poly(3‐octylthiophene) (P3OT) as the active luminescent polymer. Above the threshold voltage, current in an LEC consists of ionic and electronic components. A purely ionic (negative) component is clearly discernible in the…
Abstract Die mikroskopische Theorie von Bardeen, Cooper und Schrieffer lieferte ein grundsätzliches physikalisches Verständnis des Phänomens Supraleitung. Die Theorie stellt allerdings keinen direkten Stoffbezug her. Ausgehend von den speziellen Bindungsverhältnissen in Carbiden und Carbidhalogeniden der Seltenerdmeta…
Conducting crystalline polyazomethine polymers with high solubility and low melting points have been prepared and studied. The polymers were synthesized by the polycondensation of p-phenylene diamine and 2-nitro-p-phenylene diamine with terephthaldehyde and p-diacetylbenzene. Polymers with polar functional NO2 groups…
The non-isothermal crystallization behaviour of high purity β-phase and α-phase polypropylene (PP) and their calcium carbonate-filled composites was investigated by means of differential scanning calorimetry. High purity β-PP polymer was prepared by adding an effective β-nucleator consisting of equal amounts of pimeli…
Electrochemical growth of the polyazulene film and its electrochemical and spectroscopic properties were studied at platinum electrodes in acetonitrile by ac impedance and in situ spectroelectrochemical techniques. During polymer growth from the acetonitrile solution containing a millimolar concentration of azulene wi…