Syntheses and characterization of isotopically labeled 1,3,5‐triamino‐2,4,6‐trinitrobenzene (TATB)**

Abstract

Synthesis and characterization of chemical analogues of TATB, where specific atoms in the structure have been isotopically substituted, are reported. 15N, 2H, and 18O have replaced the naturally occurring isotope distributions in the amino and/or the nitro attendant sites and 13C has replaced the carbon in the ring structure. A modified wet‐amination method was used to produce the analogues, and the isotopic replacements were performed by selective choice of labeled precursors. Four 15N‐labeled compounds (N replaced in the amino and nitro positions), two deuterium‐labeled compounds (hydrogens replaced on the amino groups), and one 13C‐labeled compound (C in the ring substituted) were synthesized of high isotopic and chemical purity. One partially labeled 18O‐labeled compound (O in the nitro position) was a result of incomplete labeling due to exchange reactions during synthesis. The compounds were characterized by various spectroscopic methods – mass spectrometry (MS), solid‐state nuclear magnetic resonance (SS‐NMR), infrared (FTIR), powder x‐ray diffraction (PXRD), and differential scanning calorimetry (DSC), depending upon the substitution. These compounds have been critical to the efforts in understanding the decomposition pathways of TATB when exposed to abnormal thermal environments.

New Thermal Decomposition Pathway for TATB

“…The residual 44 m/z CO 2 in the 13 C 6 -TATB pro le is due to 94% isotopic purity. 20 It is signi cant that the 13 C material decomposes about twice as fast as 12 C material. The faster decomposition was veri ed using thermal analysis (simultaneous mass loss and heat ow) at both isothermal and constant heating rate conditions using methods described elsewhere.…”

“…% chemically pure. The 18 O labeled was introduced by the same synthesis method as in delineated elsewhere 20 with modi cations of trichloro benzene nitrated with KN 18 O 3 . Only partially substituted products were isolated due to exchange with the acids during synthesis -1 18 O-nitro group: 32.44%; 2 18 O-nitro groups: 7.87%; 3 18 O-nitro groups: 1.04%.…”

New thermal decomposition pathway for TATB

“…For unlabeled-TATB there is almost no intensity for m/z 45 while for the 13 C 6 -TATB, the profile shows m/z 45 ion evolving both early and late. The residual 44 m/z CO 2 in the 13 C 6 -TATB profile is due to 94 % isotopic purity 19 .

Figure 3 EGA-GC-MS of TATB ( A ), inset, m/z 45 scaled 500 X ( B ), and 13 C 6 -TATB ( C ) at 330 °C: total ion current and extracted ion chromatograms for m/z 45 and 44 are shown with black, red, and blue lines, respectively.

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TATB thermal decomposition: An improved kinetic model for explosive safety analysis

“…To further elucidate the species formed during thermal decomposition, TATB of high chemical purity, as well as 13 C, D, 15 N, and 18 O isotopically-labeled TATB [21,22], were studied using PyGC-MS and Py-MS in EGA (evolved gas analysis) mode at elevated temperature (> 300 °C). These experiments are discussed in detail in Morrison, et al [13].…”