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61.
Alemani M Peters MV Hecht S Rieder KH Moresco F Grill L 《Journal of the American Chemical Society》2006,128(45):14446-14447
The electric field applied between the tip of a scanning tunneling microscope and a metallic surface is shown to induce the reversible trans-cis isomerization of single azobenzene derivatives adsorbed on a Au(111) surface. The investigated molecule is symmetrically equipped with four tert-butyl groups, which decouple the azobenzene core from the metallic surface, facilitating the formation of highly ordered islands. Due to the spatial extension of the electric field, it is possible to switch many molecules within the same island simultaneously. 相似文献
62.
Facile rearrangement of azobenzenes is shown to occur in cases where the azo group is placed in the ortho position to carbonyl electrophiles to furnish the indazole skeleton. While this study demonstrates the illusive nature of o-formylazobenzenes, it offers potential for the synthesis of indazoles and related heterocycles. 相似文献
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Taking the regio‐ and chemoselectivities of our iron complex precursors with pyridine core in aerobic oxidations into account, we envisioned a more effective influence on catalytic properties by the introduction of different substituents in 4‐position of the pyridine moiety. The synthesis of these novel 4‐substituted (pyridine‐2,6‐diyl)dipropanoic acids 4 is described. Analogously to the unsubstituted derivative, ligands 4 reacted with Fe(ClO4)3 to form trinuclear Fe3(μ3‐O) complexes 3 , which were tested in the aerobic Gif‐type oxidation of α‐pinene to myrtenol, verbenone, myrtenal, and pinene oxide. The electronic nature of the substituents was found to slightly effect the ratio of allylic oxidation/epoxidation, whereas its influence on the oxidation preference of secondary to primary C? H bonds is negligible as compared to the unsubstituted complex. 相似文献
65.
Christoph Blaszk Jan Grünitz Maike Möller Werner Pauer Hans-Ulrich Moritz Christian Schwede 《Macromolecular Symposia》2007,259(1):348-353
Summary: Since copolymerization parameters of acrylic acid (AA) and 2-hydroxypropyl acrylate (HPA) in aqueous solutions are scarcely investigated a new method and different experimental setups were developed to run copolymerization experiments at different temperatures and pH values. The experiments were done with UV- or azo- initiation and analyzed by residual monomer analytics with HPLC and GPC methods. Based on the data obtained the conversion and copolymerization parameters were calculated with different mathematical models. 相似文献
66.
Christiane Rabe 《Nachrichten aus der Chemie》2007,55(4):472-473
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Attenuated total reflection and photoacoustic measurements have been employed to study the decay channels of plasmon surface polaritons optically excited at the Ag-air interface. We show that it is possible to analyse the radiative and non-radiative decay quantitatively by comparing measurements taken with transparent and blackened cavities, respectively. In the first case only light that is thermalized by radiationless processes in the Ag film produces a photoacoustic signal. In the blackened cell, however, light that is either transmitted through the Ag film or reemitted by the radiative decay of excited polaritons also contributes to the photoacoustic intensity. 相似文献