Zur thermischen zersetzung der 3d-übergangsmetalloxalate

Thermal decomposition of cobalt, manganese, and nickel oxalates has been investigated in vacuum and air with the use of a vacuum microbalance, and in air by derivatography. It was found that in vacuum in the first step, the cobalt and manganese oxalates are decomposed into oxides, but the nickel oxalate into metallic nickel—depending on the magnitude of the crystal field stabilization energy. In secondary reactions, oxides of Co and Mn will partly be reduced by the evolved CO to the metal, and a minute part of the metallic Ni can be oxidized depending on the partial pressures of the O₂, CO₂, and H₂O components of the residual gas. In air, the first step ofthe thermal decomposition is the Me²⁺å Me³⁺ oxidation of the central cation; this is also obtained from the linear relationship between the temperature of the maximum decomposition rate and the ionization energy. Some inconsistencies found in the literature have been elucidated. Deviations appearing in inert and oxidative atmosphere—with lower and higher partial pressure of O₂—showed that the thermal stability of the solid complexes is influenced by the surrounding atmosphere similar to the stability of dissolved complexes in a solvent.     

Zur Kenntnis der Verbindung H3P–BJ3

Phosphine or phosphonium iodide react with boron triiodide in CS₂ or benzene to form the adduct H₃P–BI₃. The water-sensitive white solid is thermally stable up to ～150°C. Its IR and NMR spectrum are recorded.     

Über den Zusammenhang zwischen der Spektrographenspaltbreite und dem γ-Wert der Spektralplatten bei verschiedenen Wellen-längen

The influence of the spectrograph slit width on the slope γ of the photographic emulsion has been investigated. By varying the slit width a maximum value of γ can be obtained which occurs at different slit widths with prism and grating spectrographs but which is independent of the emulsion type of the photographic plate. An explanation for these phenomena is given which at the same time solves the discrepancies in the results published by other authors. The maximum value of the slope can naturally be determined more accurately than other γ values. Consequently its use should result in more accurate spectrochemical analyses.