Abstract: he molecular geometries, heats of formation, electronic structures of three trinitrobenzenes(1,2,3-TNB, 1,2,4-TNB, 1,3,5-TNB), their chloro derivatives were studied by using the quantum chemical MO AM1 method at the RHF level, ab initio method at the HF/3-21G level. The decompositions of the title compounds were investigated by using the AM1 method at the UHF level. The decomposition activation energies were obtained, the order of the relative stabilities of the title compounds is found. The substituent effects on the structures, properties, on the decompositions of the title compounds are discussed in the present paper.

Key words: Trinitrobenzene, Molecular orbital method, Molecular structure, Stability, Decomposition