Spektrochemische Bestimmung von Gallium -, Indium-Und Thalliumspuren unter Benutzung der Extraktionssysteme mit Drei Flussicen Phasen

Abstract

A new method for concentrating of microgram amounts of elements before their spectral determination is described. The method is based on the diantipyrilethanes property to divide the organic solvent into two phases, i. e., during the extraction of elements the three liquid phase system is formed. In one of the phases (the “third phase”) 93–98% of the extractable elements are concentrated. Owing to the small volume the third phase may be dropped onto electrodes avoiding evaporating, ashing of extracts and filling of electrodes before spectral determination. This twice of three times reduces the duration of analysis and increases the accuracy and sensibility of determinations. Based on the three liquid phase system the spectrochemical method of the microgram amounts determination Ga, In and Tl(II1) in Mg, Be, Al, Sc, Y, La, Ce, Zn, Cd, Pb has been developed. The use of such systems in analytical chemistry would be perspective.     

Shape‐Assisted Self‐Organization in Highly Disordered Liquid Crystal Phases

In achiral rod‐like molecules, a nematic phase is the most disordered liquid crystal phase, which only has one‐directional order in the direction of the molecular long axis. A dumbbell‐shaped molecule (compound 3 : R−C₆H₁₀−CH=CH−C₆H₄−CH=CH−C₆H₁₀−R, (R=n C₅H₁₁)), and its liquid crystal phase (X phase) are reported, which exhibit high scattering without thermal fluctuation between two nematic phases under a polarized light optical microscope. The X phase was investigated by X‐ray diffraction, scanning electron microscopy, atomic force microscopy, and molecular dynamics simulation. A layered structure was ascertained for which a molecular self‐organization mechanism was postulated in which the super‐structure is based on lateral intermolecular interlocking. A second nematic phase above the X phase consisted of “rice grain”‐shaped particles.