Bestimmung des Enantiomerenüberschusses von chiralen Ammonium-Ionen mit Hilfe von Flüssigmembranelektroden

Determination of the Enantiomeric Excess of Chiral Ammonium long Using Liquid Membrane Electrodes A cell assembly with two membranes each containing one enantiomer of a chiral ionophore is described. It is suitable for the direct potentiometric determination of the enantiomeric excess of ions. The method is used to determine the enantiomeric excess of ephedronium ions in aqueous solutions.     

Einfluß von Gitterstörungen des Graphits auf die Bildung von Graphithydrogensulfat

Influence of Lattice Defects of Graphite on the Formation of Graphite Hydrogensulfate Various natural and synthetic graphites were oxidized with chromic acid in sulfuric acid to the 1st stage of graphite hydrogensulfate with the intent of determining the inhibition of intercalation by lattice defects. More oxidant than required by stoichiometry is consumed because slow total oxidation to CO₂ is superimposed even at room temperature. The activation energy for total oxidation is reduced by lattice defects. With some graphites, separation of the intercalation reaction from total oxidation was accomplished using calorimetry. The reaction enthalpy in the oxidation of well-crystallized graphites to the graphite salt is ?3.05 kJ/mol C.