Oxidation of some aromatic amines on the passivated hanging mercury drop electrode

It has been shown that a hanging mercury drop electrode of the Kemula type is a very convenient tool for studying the redox processes of organic substances in the positive potential range. Conditions influencing the oxidation process are discussed. The method described may prove to be an analytical tool for the determination of some aromatic amines.     

Fmoc solid-phase synthesis of peptide thioesters using an intramolecularn,S-acyl shift

[reaction: see text] We describe the Fmoc solid-phase synthesis of peptide thioesters based on the alkylation of the safety-catch sulfonamide linker with a protected 2-mercaptoethanol derivative. The thioester is generated on the solid phase after the peptide chain assembly as a consequence of an intramolecular N,S-acyl shift. Depending on the stability of the spacer separating the sulfonamide linker from the resin toward TFA, treatment of the peptidyl resin with TFA led to a soluble or supported deprotected thioester.     

Lattice dynamics and ordering effects in high-concentrated α′-NbD x -alloys

The phonon dispersion of NbD _x (0.57≦x≦0.77) in [110]-direction has been determined by inelastic neutron scattering after in situ loading of the sample. Two quasioptical excitations with Γ-point frequencies of ν=3.8 THz and ν=4.2 THz, respectively, are observed along with a threefold splitting of the longitudinal acoustic branch. At the zone boundary two of these branches are getting soft when increasing the deuterium concentration. The elastic constants extracted from the initial slopes of acoustic phonon branches exhibit an anomalous behavior in the concentration range under consideration.