Zur Kenntnis der Isomerie-Erscheinungen bei den System-Insektiziden „Systox“ und „Metasystox“

Open Access
Publisher Website
Google Scholar
Abstract
The isomerization of O.O-diethylthionophos-phoric acid ([beta]-S-ethyl)-ethyl ester (Thiono-"Systox") and the corresponding O.O-dimethyl compound (Thiono-"Metasystox") are described and the significance of this reaction for the insecticidal effect of these compounds is discussed. The isomerization occurs very slowly at room temperature (temp.) but more rapidly at higher temps. Polar solvents accelerate the reaction, non-polar solvents retard them; the rearangement of thiono-Systox is more easily catalyzed than that of thiono -Metasystox. The order of the reaction of isomerization is determined by the concentration of the thiono compounds and the catalytic effect of the solvent and of the thiol compounds formed; in dilute solutions the reaction is of the 1st order. The energy of activation of the rearrangement of pure thiono-compounds was found to be 25.4 kcal/[image]_for Systox and 22.8 kcal/[image] for Metasystox.

This publication has 1 reference indexed in Scilit: