Design and Application of Amphiphilic Polymeric Supports for Micellar Catalysis

In this contribution, the synthesis and application of amphiphilic poly(2-oxazoline)s with covalently bound transition metal catalysts for reactions in aqueous media is described. In the first example, bipyridine moieties were introduced via living ring-opening polymerization of functionalized oxazoline monomers and the resulting block copolymers were used as macroligands for ATRP (atom transfer radical polymerization) using Cu(I)Br as active metal species. Furthermore, the fixation of a chiral biphosphane and its use for enantioselective hydrogenation of enamides is presented as well as the fixation of a ruthenium catalyst. The latter one is used for polymerization of diethyl dipropargylmalonate (DEDPM), and represents the first example of an alkyne polymerization using a ruthenium catalyst. In the case of the polymers stable latex particles were obtained     

Untersuchungen an Si-Epitaxieschichten auf Mg-Al-Spinell-Einkristallen

In Verneuil-grown MgAl-Spinels etch pit densities with non-uniform distribution between 10⁴ and 10⁷ cm⁻² were found. X-ray measuements of orientations showed deviations of the growth direction from the rod axis up to 8 deg. Berg-Barrett photographs point to distinctly marked substructures. Si epitaxial layers on MgAl-spinel were prepared according to the pyrolytic reductive reaction of SiCl₄ in H₂. Nucleation, etching reaction on the substrate and the quality of the Si layers are discussed. Measurements of the carrier mobility in the doping range from 10¹⁶ to 10¹⁷ · cm⁻³ resulted in 60 to 80 p.c. of the volume mobility of the silicon. Problems of segregation with annealing are dealt with. The use of Si layers on insolating substrates is discussed.