Umsetzung von amino-aziminen mit basen

Amino-azimines of type (1) react at room temperature with bases (ammonia, aliphatic amines, hydrazine and methyl-hydrazine, aqueous/ethanolic sodium hydroxide) by cleavage of the

to the

and the NNN moieties (azide).     

Probing the interaction of Au,Rh and bimetallic Au–Rh clusters with the TiO2 nanowire and nanotube support

Gold, rhodium and their coadsorbed layers were prepared on titanate nanowires and nanotubes and characterized by X-ray photoelectron spectroscopy (XPS), low energy ion scattering spectroscopy (LEIS), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). On titanate nanowire and tube supports the gold 4f_7/2 XP emission appeared after reduction at 83.7 eV and 85.6 eV indicating two different sizes or chemical environments of gold nanoclusters. The titanate nanostructures stabilize the nearly atomically dispersed state of gold (85.6 eV peaks in XPS). Small clusters also developed in rhodium containing samples besides the pure metallic state. Upon CO adsorption on Rh/titanate nanostructures the IR stretching frequencies characteristic of twin form were dominant, whereas bimetallic nanosystems featured a pronounced linear stretching vibration. By performing careful XPS, LEIS and SEM experiments, it was found that, for appropriate Au and Rh coverage, the Au almost completely covers the Rh nanoparticles. CO adsorbed on this surface may induce the surface reconstruction.     

Generalization of the Hylleraas functional for calculating BSSE-free intermolecular interactions: further considerations

The generalized Hylleraas functional necessary for calculating BSSE-free intermolecular interactions is presented for the case when exclusion of BSSE results in non-Hermitian operators and the intra- and intermolecular interactions are treated in different orders of perturbations.     

Strongly Morita Loosenesses

For the purpose of establishing relations of (-, m-)loosenesses to Cauchy structures, the papers [9] and [10] have introduced (strongly) Efremovich and (strongly) Morita loosenesses. The present paper contains further results concerning the above and some other similarly defined classes of structures.     

Location and analysis of 2-deoxy sugars on chromatograms and pherograms by fluorescence

A group of new reagents for the location of 2-deoxy sugars is introduced. A representative reagent is 4'-aminoacetophenone, which gives a green trimethine fluorogen with at least 0.5 microg of 2-deoxyribose, 2-deoxygalactose, or 2-deoxyglucose under neutral or slightly acidic conditions and the orange fluorescent anion under alkaline conditions at a lower limit of approximately 5 microg. Reagents such as 2-thiobarbituric acid, aniline-diphenylamine, and 2,4-pentanedione give vivid fluorescent colours with these sugars. Aniline-diphenylamine reagent was a useful fluorescent agent for locating the purine nucleosides and nucleotides and DNA. A new attachment for the spectropho-tofluorimeter has been evaluated. With this attachment fluorescence excitation and emission spectra are obtained directly from paper, glass fibre, or thin-layer chromatograms and pherograms in sizes up to 20 x 20 cm. Glass plates are handled as readily as paper chromatograms. The fluorescence spectra of the various fluorogens produced after separation were readily obtained directly from the chromatogram or pherogram. 2-Thiobarbituric acid and 4'-aminoacetophenone offered the greatest potential for future application to characterization and assay of 2-deoxy sugars. The aniline-diphenylamine procedure was the most useful for analysis of purine nucleosides and nucleotides and DNA. These various reagents show potential for application to air pollution studies in terms of location, characterization and assay of 2-deoxy sugars and their derivatives.     

Thin-layer chromatographic separation and analysis of polynuclear aza heterocyclic compounds

Many thin-layer Chromatographic systems can be used for the general separation of aza heterocyclic compounds from polynuclear aromatic hydrocarbons. Several can be used for the separation of the aza compounds from each other. With alumina as the adsorbent the sterically hindered aza heterocyclic compounds can be readily separated from the non-hindered aza compounds.The use of the trifluoroacetic acid spot test on the thin-layer plate is discussed. Spectral data for the aza compounds are presented and discussed.