The first successful electrosynthesis of polycrystalline AgIIFBF4 and single crystalline AgIIF2 in both galvanostatic and potentiostatic conditions was achieved at the Boron-Doped Diamond electrode in anhydrous hydrogen fluoride. Silver(I) oxidation and the F2 evolution reactions are well separated in the potential scale. Temperature of performing electrosynthesis as well as BF3 overpressure were found to be key variables of the process. Impedance spectroscopy measurements provided insight into the mechanism of formation of silver(II) fluorides pointing out to the presence of HF-soluble Ag(BF4)2 intermediate. The phase purity of the products was determined by X-ray diffraction. 相似文献
The identification and control of a critical stage of polyaniline “nanotube” self‐assembly is presented, namely the granular agglomeration or growth onto nanorod templates. When the synthesis pH is held above 2.5, smooth insulating nanorods exhibiting hydrogen bonding and containing phenazine structures are produced, while below pH 2.5, small 15–30 nm granular polyaniline nanoparticles appear to agglomerate onto the available nanorod surface, apparently improving conductivity of the resulting structures by three orders of magnitude. This finding affects both fundamental theories of polyaniline nanostructure self‐assembly and their practical applications.
The reaction between AgBF4 and excess of SbF5 in anhydrous hydrogen fluoride (aHF) yields the white solid AgSb2F11 after the solvent and the excess of SbF5 have been pumped off. Reaction between equimolar amounts of AgSb2F11 and AgBF4 yields AgSbF6. Meanwhile, oxidation of solvolyzed AgSb2F11 in aHF by elemental fluorine yields a clear blue solution of solvated Ag(II) cations and SbF6- anions. AgSb2F11 is orthorhombic, at 250 K, Pbca, with a=1091.80(7) pm, b=1246.28(8) pm, c=3880.2(3) pm, V=5.2797(6) nm3, and Z=24. The crystal structure of AgSb2F11 is related to the already known crystal structure of H3OSb2F11. Vibrational spectra of AgSb2F11 entirely match the literature-reported vibrational spectra of beta-Ag(SbF6)2, for which a formulation of a mixed-valence AgI/AgIII compound was suggested (AgIAgIII(SbF6)4). On the basis of obtained results it can be concluded that previously reported beta-Ag(SbF6)2 is in fact Ag(I) compound with composition AgSb2F11. 相似文献
Micro‐Raman spectroscopy has been used to investigate the chemical micro‐heterogeneity of multiphase‐separated poly(ether urethanes) (PETU). Analysis of PETU cross‐sections by means of micro‐Raman spectroscopy revealed the nearly complete absence of soft segments in AI aggregates (called globules). These aggregates are in the order of a few micrometers in size. The composition of the matrix and the AII aggregates (spherulites) was comparable.
Example of an AFM image (sample 706, scan size 25 μm, converted to monochromatic image). 相似文献
Low-energy deuteron break-up on heavy nuclei is treated paying special attention to the neutron-nucleus interaction. The neutron-nucleus elastic scattering phase shift, the only quantity through which the neutron-nucleus interaction enters into our calculations, is split into an energy-averaged part described by the optical model and a fluctuating part. Some calculations are given in order to illustrate the effects of the neutron-nucleus interaction, along with a comparison with recent experimental results, which shows very good agreement. 相似文献
The mechanisms of the carboxylations of lithium, potassium, rubidium, and cesium phenoxides are investigated by means of the DFT method with the LANL2DZ basis set. It is shown that the reactions of all alkali metal phenoxides with carbon dioxide occur via very similar reaction mechanisms. The reactions can proceed in the ortho and para positions. The exception is lithium phenoxide which yields only salicylic acid in the Kolbe-Schmitt reaction. It is found that the yield of the para substituted product increases with increasing the ionic radius of the alkali metal used. An explanation for this experimental and theoretical observation is proposed. 相似文献
