Indo‐Mo Model with s·p Separation

J. Theor. Comput. Chem.

Zheng

2007

This study investigated the RDX (1,3,5-Trinitro-1,3,5-triazine) molecule to elucidate its possible decomposition species and the corresponding energies by performing the density-functional theory (DFT) calculations. Reasonable decomposition mechanisms are proposed based on the bond energy calculated using the differential overlap (INDO) program, which yields the weakest bonding site for reference and determines the site of easy cleavage. Computational results indicate that the activation energy of direct cis-form HONO elimination is lower than that of direct trans-form HONO elimination and that of a two-stage elimination of two forms of HONO (N-N bond fission combined with C-H bond breaking) in the initial decomposition step, which are 213.9 kJ/mol and 93.8-101.8 kJ/mol, respectively. Two possible pathways are proposed; (1) N-N bond homolytic cleavage followed by elimination of cis-form HONO, and (2) N-N bond homolytic cleavage followed by elimination of trans-form HONO.

Section: Localized Bond Energymentioning

confidence: 99%

Computational Study of Unimolecular Decomposition Mechanism of RDX Explosive

J. Theor. Comput. Chem.

Zheng

2007

“…Localized analysis methods are most relevant for the hydrogen bonds in this theoretical work. To understand the importance of intermolecular hydrogen bonds in these molecular systems, this study applies the recently developed semi‐empirical type of localized hydrogen bond analysis method 20, 21 for analyzing the “localized hydrogen bond energy (BE)” and “localized hydrogen bond order ( P μν )” of various molecular systems.…”

Section: Calculationsmentioning

confidence: 99%

“…The mixed systems contain three localized hydrogen bonds in various cases. Through useful analysis of the “localized analysis methods” of the authors 20, 21 and the energy barrier calculation, a detailed analysis of the hydrogen bonds linking the target molecular systems is conducted. As the overall reduction in energy stabilizes the molecular systems, there is strong evidence that the “hydrogen‐bonding effect” could be a major cause of such insensitivity.…”

Section: Introductionmentioning

confidence: 99%

Theoretical study of ANTO molecular systems: Causes of insensitivity of the energetic compound NTO

Int J of Quantum Chemistry

Chen

Hong

2004

Self Cite

ABSTRACT:The ANTO molecular system, which comprises the energetic compound 3-nitro-1,2,4-triazole-5-one (NTO, with its two lowest-energy conformers L 1 and L 2 ), ammonia (NH 3 ), and water (H 2 O) molecules, is introduced for a theoretical survey of corresponding geometrical structure and localized bonding character. With the medium (or solvent) of H 2 O and NH 3 , three intermolecular hydrogen bonds formed in the NTO ϩ NH 3 ϩ H 2 O system would lower the overall molecular energy and stabilize.

“…Zhang et al 11 suggested pathways of HONO elimination for TNAZ. The same pattern of HONO elimination (including cis and trans forms) is initially applied to target TNAD and TNAZ molecules herein.…”

Section: Introductionmentioning

confidence: 99%

Theoretical study of the unimolecular decomposition mechanisms of energetic TNAD and TNAZ explosives

Int J of Quantum Chemistry

Chen

Hong

2004

Self Cite

Calculation methods based on hybrid Density Functional Theory (DFT)with the basis sets of the B3LYP/6-31ϩG(d)//B3LYP/4-31G(d) method and the differential overlap (INDO) program were used to derive reasonable decomposition mechanisms of 1,4,5,8-tetranitro-1,4,5,8-tetraazadecalin (TNAD) and 1,3,3-trinitroazetidine (TNAZ) explosives. All possible decomposition species and transition states, including intermediates and products, were identified and their corresponding enthalpy of formation and Gibbs free energy of formation were obtained using polyparametric modification equations. INDO bond energy calculation results reveal the weakest bonding site for reference and determine where cleavage can occur easily. This work is concerned mainly with eliminating HONO (cis or trans form). The activation energy for trans-form HONO elimination is lower than that of cis-form HONO elimination in the initial steps of both TNAD and TNAZ decomposition, being 18.5 kJ/ mol and 33.3 kJ/mol, respectively.