Quantum chemical studies on the structures, properties and decomposition of the azido derivatives of trinitrobenzenes

The geometries, heats of formation and electronic structures of 15 azido-derivatives of 1,2,3-TNB (I), 1,2,4-TNB (II) and 1,3,5-TNB (III) have been studied using quantum chemical AM1 method at HF level. The effect of azido substitution on the structures and properties of TNBs has been discussed and the relative stability of the title compounds has been established. The processes of the decomposition of the title compounds by breaking C-NO2, C-N3 and CN-N2 bonds are investigated at UHF-AM1 level. It is shown that the decomposition of the title compounds may be initiated by the cleavage of both C-NO2 and N-N2 bonds.