TY - JOUR
T1 - Improving the Stability of All-Carbon-Nitrated Azoles through Cocrystallization
AU - Peng, Panpan
AU - Ding, Ning
AU - Zhao, Chaofeng
AU - Li, Yaqiong
AU - Liu, Jingjing
AU - Li, Shenghua
AU - Pang, Siping
N1 - Publisher Copyright:
© 2022 American Chemical Society. All rights reserved.
PY - 2022/4/6
Y1 - 2022/4/6
N2 - All-carbon-nitrated azoles have the advantages of high density and good oxygen balance, but they are rarely suitable for explosives applications due to their fatal deficiencies, such as poor thermal stability, sensitivity, and deliquescence. Cocrystallization technology provides a feasible idea to revive all-carbon-nitrated azoles in the presence of flexible structure designability and performance adjustability. In this study, three attractive energetic cocrystals 1-3 were synthesized with conjugate structure triimidazo[1,2-a:1′,2′-c:1″,2″-e][1,3,5]triazine (TT) and another all-carbon-nitrated azole [5-nitrotetrazole (HNT), 3,5-dinitro-1,2,4-triazole (HDNT), and 3,4,5-trinitropyrazole (TNP)], respectively. All the cocrystals 1-3 existed stably and safely under natural conditions and exhibited better thermal stability, frictional sensitivity (FS), and impact sensitivity (IS) than pure HNT, HDNT, and TNP. Therein, two melting points (Tm) of 2 were 61.9 and 95.5 °C higher than that of HDNT, and its decomposition temperature (Td) was 81.2 °C higher than that of HDNT. The mechanical sensitivity of 1 (FS = 80 N and IS = 24 J) was significantly improved compared with the extremely sensitive HNT (FS < 5 N and IS < 1 J). Moreover, 3 exhibited excellent controllable detonation performances (1.703 g cm-3, 6903 m s-1, and 18.0 GPa), which was better than 2,4,6-trinitrotoluene. The single-crystal structure analysis and theoretical calculation analysis showed that the formation of three cocrystals primarily depended on N-H···N, C-H···N, and C-H···O hydrogen bonds and NO2···πinteraction with a π-πstacking. The thermal stability and sensitivity of 1-3 were obviously better than that of pure energetics, which was attributed to the combination of these strong hydrogen bond interactions and weak NO2···πand π-stacking interactions. Therefore, the cocrystallization technology provides a promising method to give these "dead" all-carbon-nitrated azoles a new life.
AB - All-carbon-nitrated azoles have the advantages of high density and good oxygen balance, but they are rarely suitable for explosives applications due to their fatal deficiencies, such as poor thermal stability, sensitivity, and deliquescence. Cocrystallization technology provides a feasible idea to revive all-carbon-nitrated azoles in the presence of flexible structure designability and performance adjustability. In this study, three attractive energetic cocrystals 1-3 were synthesized with conjugate structure triimidazo[1,2-a:1′,2′-c:1″,2″-e][1,3,5]triazine (TT) and another all-carbon-nitrated azole [5-nitrotetrazole (HNT), 3,5-dinitro-1,2,4-triazole (HDNT), and 3,4,5-trinitropyrazole (TNP)], respectively. All the cocrystals 1-3 existed stably and safely under natural conditions and exhibited better thermal stability, frictional sensitivity (FS), and impact sensitivity (IS) than pure HNT, HDNT, and TNP. Therein, two melting points (Tm) of 2 were 61.9 and 95.5 °C higher than that of HDNT, and its decomposition temperature (Td) was 81.2 °C higher than that of HDNT. The mechanical sensitivity of 1 (FS = 80 N and IS = 24 J) was significantly improved compared with the extremely sensitive HNT (FS < 5 N and IS < 1 J). Moreover, 3 exhibited excellent controllable detonation performances (1.703 g cm-3, 6903 m s-1, and 18.0 GPa), which was better than 2,4,6-trinitrotoluene. The single-crystal structure analysis and theoretical calculation analysis showed that the formation of three cocrystals primarily depended on N-H···N, C-H···N, and C-H···O hydrogen bonds and NO2···πinteraction with a π-πstacking. The thermal stability and sensitivity of 1-3 were obviously better than that of pure energetics, which was attributed to the combination of these strong hydrogen bond interactions and weak NO2···πand π-stacking interactions. Therefore, the cocrystallization technology provides a promising method to give these "dead" all-carbon-nitrated azoles a new life.
UR - http://www.scopus.com/inward/record.url?scp=85126612862&partnerID=8YFLogxK
U2 - 10.1021/acs.cgd.1c01237
DO - 10.1021/acs.cgd.1c01237
M3 - Article
AN - SCOPUS:85126612862
SN - 1528-7483
VL - 22
SP - 2158
EP - 2167
JO - Crystal Growth and Design
JF - Crystal Growth and Design
IS - 4
ER -