Chemistry of Tetraazapentalenes

Abstract

2,4,8,10-Tetranitrobenzotriazolo[2,1-a]benzotriazole (TACOT), although thermally very stable and insensitive as an explosive, is susceptible to attack by nucleophiles. Reaction with azide ion results in displacement of nitro groups at the 4,10-positions, treatment with methoxide ion effects displacement of the hydrogen atom at the 1-position and scission of the remote triazole ring, while “vicarious nucleophilic amination” displaces all the aromatic hydrogens. 3,5,7-Trinitro-1,2,3-triazolo[2,1-a]benzotriazole and 3,5,7-trinitro-1,2,3-triazolo[1,2-a]benzotriazole are prepared readily by nitration of the parent triazolobenzotriazoles. However they are thermally less stable than TACOT and more sensitive to initiation by impact. Furthermore, attempted further nitration and reaction with nucleophiles such as azide and methoxide ions both effect scission of the triazole ring to leave 4,6-dinitrobenzotriazole.