The ammonium nitrate and its mechanism of decomposition in the gas phase: a theoretical study and a DFT benchmark.

The decomposition mechanism of ammonium nitrate in the gas phase was investigated and fully characterized by means of CBS-QB3 calculations. Five reaction channels were identified, leading to the formation of products (N2, H2O, O2, OH, HNO, NO3) found in the experimental works. The identified mechanism well underlines the origin of the chemical hazard of ammonium nitrate which is related to the exothermicity of the lowest decomposition channels.

The mechanism of the Stevens and Sommelet-Hauser rearrangements. A theoretical study.

The [1,2] and [2,3] migration steps in the Stevens and Sommelet-Hauser rearrangements which occur in the ylides of quaternary ammonium salts have been studied at M05-2x levels. The Stevens migration has been found to take place through a diradical pathway in several cases (tetramethylammonium, benzyltrimethylammonium, benzylphenacyldimethylammonium ylides). By contrast, in the phenyltrimethylammonium ylide this reaction takes place through a concerted process.