Reaktionen von 2H-isoindolen mit aktivierten azo-verbindungen

The chemical behaviour of alkyl substituted 2H-isoindoles towards dialkyl-azodicarboxylates has been investigated and the structure of the resulting 1:1- and 1:2-adducts elucidated. The reaction of the o-quinonoid hetarenes with the activated dienophiles can be considered as a Michael addition.     

Correlation of TLC/densitometry-data with capillary GC-data of some main volatile components of essential oils

The results of the densitometric and the capillary gas chromatographic investigations of numerous lavender oils of different origin and of essential oils of the woody group were correlated. Especially the main components, the monoterpenes linalool (¯1) and linalyl acetate (¯2), were quantified by densitometry with an average standard deviation of 6–7% in the examined oils. The use of TLC in combination with densitometry in the quantification of the main components to essential oils is thus a valuable addition to capillary gas chromatographic investigation. In addition to this, a useful and efficient alternative is given to groups specialized in TLC/densitometry to obtain data on such volatile compounds of essential oils during quantification. The use of TLC/densitometry thus combines the advantage of LC-with detection of also less volatile compounds—and the possibility of the parallel investigation of more samples in one step in a very efficient way.     

Die Deutung des Energie-Impuls-Tensors des Dirac-Feldes

By comparing the structure of the particle current and of the energy and momentum density, the meaning of the various tensor components is clarified. We decompose the energy momentum tensor into two parts. The one describes orbital, the other spin properties.     

Über Eisen(III)-Komplexe mit Phenolen. IV. Säurekonstanten einiger Polyphenole

The apparent acid constants of some polyphenols and of derivates from salycilic acid are determined by potentiometry using glass or hydrogen electrodes and by UV spectrophotometry on comparable conditions respectively. Anaerobic manipulations were strictly used to avoid autoxidation. The results can be interpreted qualitatively, if the possibility of the formation of intramolecular hydrogen bridges is considered besides the effects of substituting groups.