First-Principle Study on High-Pressure Behavior of Crystalline Polyazido-1,3,5-triazine

Abstract

A detailed study on the structural, electronic, and thermodynamic properties of the solid polyazide 4,4′,6,6′-tetra(azido)azo-1,3,5-triazine (TAAT) under the hydrostatic pressure of 0−100 GPa was performed using the plane-wave density function theory method. The predicted crystal structure compares well with the experimental results at the ambient pressure. The results show that a pressure less than 40 GPa does not significantly change the crystal and molecular structures. When the higher pressure is applied, the molecular geometry, band structure, and density of states change regularly except at 48 and 90 GPa where the azide−tetrazole transformation occurs. At 48 GPa, the tetrazole rings are almost coplanar with the triazine rings, whereas it has a big deviation at 90 GPa. The azide cyclization for polyazido-1,3,5-triazine has not been observed in the gas phase or polar solvents. Moreover, the band gap reduction is more pronounced in the low-pressure range than in the high-pressure region. The band gap decreases to nearly zero at 70 GPa. This means the electronic character of the organic crystal has metallic properties. An analysis of density of states shows that the electronic delocalization in TAAT increases generally under the influence of pressure. This shows that an applied pressure may increase the impact sensitivity.

Preparation, morphologies and thermal behavior of high nitrogen compound 2-amino-4,6-diazido-s-triazine and its derivatives

“…It has been found that TAHT has better thermal stability than its analogue TAAT, which is in agreement with the experimental results [26,27]. Further theoretical investigations have been carried out for both TAHT and TAAT in terms of their geometric and electronic parameters by considering the effect of the crystalline field [28,29]. Another compound which contains 4,6-diazido-1,3,5-triazineyl group is 4,6-diazido-N-(2,4,6-trinitrophenyl)-1,3,5-triazin-2-amine (TANDAzT).…”

Multistep Thermolysis Mechanisms of Azido-s-triazine Derivatives and Kinetic Compensation Effects for the Rate-Limiting Processes

“…It has been found that TAHT has better thermal stability than its analogue TAAT, which is in agreement with the experiments [19][20][21] . Further theoretical investigations have been carried out for both TAHT and TAAT in terms of their geometric and electronic parameters by considering the effect of the crystalline field 22,23 . TAHT has theoretical heat of sublimation of 38.68 kcal mol -1 , while its detonation velocity and detonation pressure in solid state are predicted to be 7.44 km s -1 and 23.71 GPa,…”

Effects of Electronic Delocalization and Hydrostatic Compression on Structure and Properties of Cage Compound 4‐Trinitroethyl‐2,6,8,10,12‐pentanitrohexaazaisowurtzitane

“…Plainly, the latter is simpler and instructive. In fact, it has been widely used in the field of energetic materials …”

“…In the past decades, our group has done lots of studies about high energetic materials on various properties . Among them, a nitro cage compound, namely 4‐trinitroethyl‐2, 6, 8, 10, 12‐pentanitrohexaazaisowurtzitane (TNE‐CL‐20) (in Figure ) prepared in recent years (in Figure ), was researched on its structural and energetic properties in gas phase .…”