Thermal Stability of Dibenzo-21-crown-7 and Its Solution in 1,2-Dichloroethane in Contact with Nitrogen Dioxide

The thermal stability of dibenzo-21-crown-7 (DB21C7) and its solution in 1,2-dichloroethane (DCE) after contact with nitrogen dioxide, which is a product of nitric acid degradation, was studied. It is shown that exothermic processes accompanied by the release of gaseous products are observed in inert and oxidizing atmosphere. The compounds formed after contact with nitrogen dioxide were determined by gas chromatography–mass spectrometry. Differences in gaseous products in the temperature range of 300℃ were defined for the initial crown ether and for DB21С7 and its solution in DСE after contact with NO₂.