DFT Studies on Detonation Properties, Pyrolysis Mechanism, and Stability of the Nitro and Hydroxyl Derivatives of Benzene

Abstract

Ninety-one nitro and hydroxyl derivatives of benzene were studied at the B3LYP/6-31G* level of density functional theory. Detonation properties were calculated using the Kamlet-Jacobs equation. Three candidates (pentanitrophenol, pentanitrobenzene, and hexanitrobenzene) were recommended as potential high energy density compounds for their perfect detonation performances and reasonable stability. The pyrolysis mechanism was studied by analyzing the bond dissociation energy (BDE) and the activation energy (E a ) of hydrogen transfer (H-T) reaction for those with adjacent nitro and hydroxyl groups. The results show that E a is much lower than BDEs of all bonds, so when there are adjacent nitro and hydroxyl groups in a molecule, the stability of the compound will decrease and the pyrolysis will be initiated by the H-T process. Otherwise, the pyrolysis will start from the breaking of the weakest C-NO 2 bond, and only under such condition, the Mulliken population or BDE of the C-NO 2 bond can be used to assess the relative stability of the compound.

New Application of Hydroxyl Groups: Ligands for High Density Metal Organic Frameworks

“…For example, the introduction [18] of the hydroxyl group to 5-aminotetrazole could increase the density from 1.502 g cm À3 (5-aminotetrazole) to 1.695 g cm À3 (1-hydroxy-5-aminotetrazole), while the density of 1-hydroxy-5-aminotetrazole was also higher than that of the corresponding 1,5-diaminotetrazole (1.571 g cm À3 ). Organic explosives [19] with hydroxyl groups do not show superiority in improving the heat of detonation, or other properties, when compared to those of other groups. However, the hydroxyl group is an easily ionized functional group with strongly electrophilic characteristics, which may strengthen [20] hydrogen bonds, obviously improving [21][22][23] for the density of energetic materials.…”