Synthesis, characterization and properties of a novel energetic ionic salt: dicarbohydrazide bis[3-(5-nitroimino-1,2,4-triazole)]

Article abstract of DOI:10.1039/c8nj05416a

Dicarbohydrazide bis[3-(5-nitroimino-1,2,4-triazole)] (DCBNT) was firstly synthesized by ion exchange and salt formation reaction. A combination of single-crystal X-ray diffraction (SXRD), FTIR, ¹H NMR, ¹³C NMR, and elemental analysis was utilized to analyze the structure and composition of DCBNT. DCBNT exhibits a high detonation velocity of 9234.87 m s^?1 and a detonation pressure of 31.73 GPa as calculated by EXPLO5 v6.02 program. In addition, the sensitivities (impact sensitivity >40 J, H₅₀ = 90 cm, and friction sensitivity = 216 N) and thermal stability (>230 °C) of DCBNT were investigated. Moreover, we measured the solubility of DCBNT in 12 common solvents by a polythermal method system which demonstrates its poor solubility in common organic solvents and water. These excellent physicochemical properties make DCBNT an environmentally friendly, low-sensitivity and high-energy explosive.

Full text of DOI:10.1039/c8nj05416a

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ISSN 1144-0546
PAPER
Jason B. Benedict et al.
The role of atropisomers on the photo-reactivity and fatigue of
diarylethene-based metal–organic frameworks
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DOI: 10.1039/C8NJ05416A
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Synthesis, characterization and property analysis: a novel
energetic ionic salt of dicarbohydrazide bis[3-(5-nitroimino-1,2,4-
triazole)]
Received 00th January 20xx,
Accepted 00th January 20xx
Jianrong Ren,a,b Dong Chen,b Guijuan Fan,b Ying Xiong,b Zhenqi Zhang, b Yanwu Yu,a*
Hongzhen Lib*
DOI: 10.1039/x0xx00000x
www.rsc.org/
Dicarbohydrazide bis[3-(5-nitroimino-1,2,4-triazole)] (DCBNT) was firstly synthesized by ions exchange and salt formation
reaction. A combination of single-crystal X-ray diffraction (SXRD), FTIR, 1H NMR, 13C NMR, and elemental analysis was utilized
to analyze the structural character and composition of DCBNT. DCBNT exhibits high detonation velocity of 9234.87 m s-1 and
detonation pressure of 31.73 GPa calculated by EXPLO5 v6.02 program. In addition, DCBNT was investigated in the aspect of
sensitivities (impact sensitivity >40 J, H50 value of 90 cm and friction sensitivity is 216 N) and thermal stability (>230 ℃).
Moreover, we measured solubility of DCBNT in 12 common solvents by a polythermal method system which demonstrates its poor
solubility in common organic solvents and water. These excellent physicochemical properties make DCBNT an environmental-
friendly low-sensitive high-energetic explosives.
similar nonionic compounds, so they have unique advantages in
many aspects.11,25-26 What is more, the main decomposition
products of these compounds were dinitrogen, which can avoid
Introduction
environmental pollution as well as health risks.13,27-28
Therefore, these materials, such as TKX-50,29 MAD-X130 and
CBNT carbonic dihydrazidinium bis[3-(5-nitroimino-1,2,4-
triazolate)]31-32 etc., had achieved considerable attention in
recent years.
High energy density materials (HEDMs) have been
increasingly used in both military and civilian fields for the past
two centuries.1 Nevertheless, for traditional HEDMs, although
great progress has been achieved in terms of their performance
and behavior,2-3 it is still difficult to simultaneously show a
good balance between the high energetic performance and low
sensitivity.4 So, there has been an urgent requirement for high
energy as well as safety, which represents admirable
performance, for example good thermal stability, high density,
high detonation characteristics, low sensitivity, and good
environmental compatibility.1-13 Specially, environmental
adaptability of explosive became more and more important in
the harsh war environment. There are only limited number of
low-sensitive high-energetic explosives, such as TATB,14-16
LLM-105,17-18 FOX-7,19-21 NTO,22 etc. has been synthesized.
So, there has been a growing interest in the synthesis of new
low-sensitive high-energetic explosives.23-24
CBNT is a typical triazole energetic ion salt,32-33 which
consists of one carbonyl hydrazide cation and one BNT2- anion,
both are with two charges. The measured density of CBNT is
1.95 g cm-3, the calculated detonation velocity and detonation
pressure are 9316.89 m s-1 and 33.40 GPa (calculated by
EXPLO5 v6.02 program), respectively, so CBNT was
considered as an alternative substitution of RDX.11 However,
the single crystal of CBNT is very difficult to obtain and its
crystal structure have not been revealed. Since carbonyl
hydrazine contains two hydrazine groups, it can receive one or
two protons to form monovalent or two valent cations. So, in
order to verify whether BNT and carbonyl hydrazine can be
combined in different ratios into new energetic salts, and to
obtain more assistant information of CBNT, we conducted
experiments. The new compound may have similar
characteristics and properties compared with CBNT.
The energetic salts based on nitrogen-rich heterocycles,
especially the triazole or tetrazole ring, exhibits intrinsically
lower vapor pressure, higher positive heat of formation, better
thermal stability, and higher densities than their atomically
In the text, we synthesized a kind of new material
dicarbohydrazide bis[3-(5-nitroimino-1,2,4-triazole)] (DCBNT)
based on BNT2- anions and monovalent carbonyl hydrazine
a. College of Environment and Safety Engineering, North University of China,
Taiyuan 030051, China
b.
Institute of Chemical Materials, China Academy of Engineering Physics, Sichuan,
cations.
The
synthesis
method,
crystal
structural
Mianyang 621900, China.
characterization, thermal properties, detonation performances
and solubility of DCBNT have been studied and compared with
† Footnotes relating to the title and/or authors should appear here.
Electronic Supplementary Information (ESI) available: CCDC 1580504. For ESI and
crystallographic data in CIF or another electronic format see
DOI: 10.1039/x0xx00000x
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CBNT, which will provide guidance and reference for later
research about CBNT and triazole salts.
View Article Online
DOI: 10.1039/C8NJ05416A
DCBNT was fully characterized through FTIR, 1H NMR, 13
C
NMR (SI Fig. S1) and EA. Furthermore, single-crystal X-ray
diffraction method was used to measure its crystal structure.
The IR spectrum of DCBNT can be seen in Fig. S2 in SI. In the
1H NMR ([D6] DMSO) spectra, the signal for the N–H proton
resonance of the triazole cation occurred at δ = 8.05 ppm (s,
brs), and the amino and amide groups of the carbohydrazide are
found at δ = 6.15 ppm as a very broad peak (for more details,
refer to Fig. S1 in SI). In the 13C NMR spectra, the signals in
the 13C NMR ([D6] DMSO) spectrum of salt were found at δ
(ppm) = 160.71 [C=O], 157.04 [CH=N], and 151.07 [C-C] and
the shifts corresponding to the cation and anion in this study are
in good agreement with previously recorded shifts for the
relevant cation and anion (Shreeve et al. 2010;32 Dippold et al.
201233).
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Results and discussion
Synthesis
At present, reports on CBNT are focused on the improvement of
synthetic methods. According to Shreeve group's reports,31,32,33 the
synthetic method of H2BNT has been very mature. More special is
that the metathesis reactions of Na2BNT with monocationic halides
in hot water resulted in the formation of corresponding energetic
salts. In terms of the synthesis method, H2BNT was synthesized
according to the method of H2BNT in CBNT. In our study, the
NaOH solution was added dropwise to the aqueous solution of
H2BNT instead of the suspension. Next to it, a certain amount of
positive monovalent carbohydrazide hydrochloride was added to the
Na2BNT solution at 70 ℃, and the product is washed with cold
water, no rest during the period. What is different from Shreeve
group’s is that Na2BNT solution was held in air for several days,
then an excess of the relevant salts was added to the hot aqueous
solution of Na2BNT and the final product was washed with hot
water. The yield of DCBNT in our work was 65%, slightly lower
than 87% of CBNT.
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Crystalline
carbohydrazide
bis[3-(5-nitroimino-1,2,4-
triazole)] salt based on BNT2- with a molar ratio of 1:1 has been
reported by Shreeve’s group.32 However, by controlling the
molar ratios and reaction conditions, the ratios between cations
and anions of DCBNT obtained herein was 2:1. DCBNT
crystallizes in the monoclinic P 21/n space group and contains 2
molecules in the unit cell and has a density of 1.780 g cm-3.
As shown in Fig. 1, DCBNT consists of two carbohydrazide
cations and one BNT2- anion, which are linked by ionic bonds
and hydrogen bonds. The two hydrogen atoms of the trazole
rings (N1 and N1A) are lost in the reaction and transferred to
the nitrogen atoms (N7 and N7A) of carbohydrazide, which can
be presented as 2[(C1H7N4O)+](C4N10O2)2–. It was constructed
by the effect of hydrogen bonds such as N1–H1···O1 and N1–
H1···N6 and π-π interaction to form a stable structure.
The results show that BNT and carbohydrazide can be combined
in a ratio of 1:1 or 1:2 by adjusting the valence number of the raw
materials and there was not any report before.
Structural description
Table 1. Crystal data and structure refinement for DCBNT
Compound
DCBNT
Partial bond lengths and angles of DCBNT are given in SI
Table S1. In the BNT2- anion, the data about bonds show that
the N1-C2(1.360 Å) and N4-C1(1.380 Å) bond lengths in the
azole ring are closer to the standard bond length of the C=N
double bond(1.35 Å) than to that of the C-N single bond (1.47
Å), whereas the N1-C1(1.342 Å), N2-C2(1.307 Å) and N3-
C1(1.318 Å) bond lengths are considerably longer than the
C≡N triple bond (1.16 Å) but slightly shorter than the C=N
double bond. The N2-N3 and N4-N5 bond lengths are 1.366
and 1.316 respectively, which are between N-N single bond
(1.45 Å) and N=N double bond (1.25 Å). The bond lengths of
remaining bonds are also all within the range of formal C-C, N-
O single and double bonds (C-C: 1.54 Å, C=C: 1.34 Å; N-O:
1.46 Å, N=O: 1.14 Å). These results support the presence of
some multiple-bond character, demonstrating that the trazole
rings and N-NO2 exist as delocalized π system.
Besides, the data of crystal (SI Table S2) show that the
molecule is symmetric along C2-C2#, because the bond lengths
and angles on both sides are the consistent. Moreover, the
torsion angle of ammonium nitrates base in the plane of the
triazole rings as shown by N5-N4-C1-N3 is 3.4(6) °, which
means that the ammonium nitrate base and the triazole ring are
incompatible. The torsion of N3-N2-C2-C2 and C1-N1-C2-C2
are -179.5(4) °, -180.0(6) ° respectively, indicted that two
triazole rings in DCBNT anion exhibit coplanar arrangement.
What’s more, in addition to the surface of N9-N8-C3-O3 (178.1
Empirical formula
C6H18N18O6
Formula weight
436.37
Crystal system
monoclinic
P 21/n
Space group
temperature/K
293(2)
Crystal size [mm3]
0.35×0.25×0.02
4.8647(3)
25.2903(17)
6.7166(5)
90
a/Å
b/Å
c/Å
α(°)
β(°)
99.765(7)
90
γ(°)
V(Å3)
814.36(10)
2
Z
ρcalc g cm-3
θ(°)
1.780
3.181-26.372
452
F(000)
Reflections collected
5101
-6≤h≤5, -31≤k≤30, -8≤l≤7
Index ranges
Rint
0.0686
Data / restraints /
parameters
1660 / 4
144
Final R index [I >2σ(I)]
Final R index [all data]
GOF on F2
R1=0.0978, wR2=0.1702
R1=0.1613, wR2=0.1881
1.091
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(6) °), incoplanar features can also be observed in
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DOI: 10.1039/C8NJ05416A
carbonylhydrazine cations from the data of angle for DCBNT.
Hydrogen bond is an important influence factor on the
molecular packing and crystal structure, thus it can help to
increase the thermal stability and density, meanwhile decrease
the sensitivity of the ionic salts.25, 34-35 As shown in Fig. 2, there
are a lot of intramolecular hydrogen bonds on carbonyl
hydrazine cation, for example, comparatively stronger
hydrogen bonds N7-H7C···N4(D···A: 2.806 Å; D–H···A:
172.06 °), N7-H7A···O1(D···A: 2.925 Å; D–H···A: 157.90 °),
connected to the carbonyl hydrazine cation with triazole ring
and ammonium nitrate on triazole ring. Meanwhile, the
hydrogen bonds between the anion-anion and the cation-cation
belong to N3-H···N2 and N9-H9A···O3, respectively, each
molecule is both the proton donor and the proton acceptor of
the hydrogen bonds. Hydrogen bond information is displayed in
Table 2. Besides hydrogen bonds interactions, there are π-π
stacking interaction (black dash) between closest BNT2-s. In
addition, BNT2-s are connected by carbohydrazide+ in the b-
axis to form wavy-like chains that are parallel to each other
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Fig. 1 Representation of the solid-state molecular structure of
DCBNT, molecular structure thermal ellipsoids are shown at the
50% probability level.
(Fig. 3). It is obviously that strong intermolecular hydrogen
bond interactions may be responsible for the good thermal
stability of DCBNT. At the same time, the wave-live structure
enables DCBNT to have low impact sensitivity.36,37-39 The huge
three-dimensional network structure of DCBNT is as shown in
Fig. 2
.
Table 2. Hydrogen bonds present in DCBNT.
D-H…A
d(D-H)/Å
d(H…A)/Å
d(D…A)/Å
<(DHA)/°
N3-H3…N2
N6-H6…O3
N7-H7A…O1
N7-H7A…O2
N7-H7B…N1
N7-H7C…N4
N8-H8…O2
0.860
0.860
0.890
0.890
0.890
0.890
0.860
2.396
2.009
2.081
2.489
2.412
1.922
2.240
2.966(54)
2.690(58)
2.923(60)
3.170(58)
3.089(58)
2.806(53)
2.970(59)
124.157(283)
135.326(319)
157.897(276)
133.719(271)
133.076(268)
172.062(281)
142.700(325)
Fig. 2 (a)Intermolecular hydrogen bonds in DCBNT represented by
green dashes, (b)π-π interaction of DCBNT represented by black
dashes, (c) Plane angle.
N9-H9A…O3
0.895
2.416
3.256(85)
156.501(1848)
Fig. 3 Wave-like staking of DCBNT.
Thermal decomposition
The thermal stability is significant feature for energetic materials,
because it is directly related to the thermal safety and further
applications. Therefore, the thermal stability of DCBNT was
investigated by TG-DSC at a heating rate of 10 °C min-1 in flowing
high purity nitrogen, the test temperature range is 0–400 °C. The
TG-DSC curves for DCBNT are shown in Fig. 4.
Fig. 4 shows that there are three obvious mass-loss stages (stages
I–III) in TG curve, corresponding to the three peaks in DSC curves.
For TG curve stage I begins from about 205.33 ℃ and stops at about
235.35 ℃, accompanying 19.59% mass-loss, with the summit peaks
in DSC curves at about 232 ℃, corresponding to the main
exothermic peak. Then two subordinate exothermic peaks followed,
correspond to the stage II and Ⅲ. Stage II begins followed by stage I
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and stops at about 266 ℃, accompanied by about 22% mass-loss, is demonstrating that the results are credible. The activation energy
View Article Online
DOI: 10.1039/C8NJ05416A
E obtained by Kissinger's method and Ozawa-Doyle's are 258.37 and
253.70 kJ mol-1, which agree well with each other. Accordingly, the
Arrhenius equations for DCBNT can be expressed by Ea (average of
Ek and Eo) and lnA, as shown in equation (1):
after that is stage III with about 10% mass-loss, which attributes to
the continue decomposition of carbonylhydrazine in DCBNT.
Moreover, DCBNT has higher main decomposition peak 232 ℃ than
CBNT (222 ℃),32 means that the thermal stability of DCBNT is
better than that of CBNT.
ퟏퟎퟑ
(1)
퐥퐧 풌 = ퟓퟒ.ퟖퟎퟎ ― ퟐퟓퟔ.ퟎퟑퟓ ×
푹푻
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The equations can be used to estimate the rate constants for the
thermal decomposition processes of compound DCBNT and predict
its thermal decomposition mechanisms.
Table 3. The calculated kinetic parameters for the first exothermic
decomposition processes of DCBNT
β(℃ min-1)
TP (℃ min-1)
Kissinger
lnA
Ozawa
EK
rK
EO
rO
5
227.04
231.96
235.05
238.24
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15
20
258.37
54.80
0.992
253.70
0.993
Fig. 4 TG-DSC curve for DCBNT.
Non-isothermal kinetics
In order to fully evaluate the thermal stabilities of the energetic
salts, the self-accelerating decomposition temperature (TSADT) and
critical temperature of thermal explosion (Tb), are necessary for
energetic compounds. The values (T00, Te0 and Tp0) of the initial
temperature point corresponding to β →0 are also obtained by
equation (2). The values of TSADT and Tb for compounds DCBNT
are obtained by equations (3) and (4). The values of the propellants
are listed in SI Table S3.
In this work, Kissinger’s method (Kissinger40) and Ozawa Doyle’s
method (Doyle 196141; Ozawa 196542) were applied to determine the
kinetic parameters of the exothermic decomposition process of
DCBNT. The apparent activation energy (E) and the pre-exponential
factor (A) was universally applied in this field, depending on the
peak temperatures measured at four different heating rates of 5, 10,
15, and 20 ℃ min-1 (Fig. 5 and SI).
(1)
(2)
ퟐ
ꢀ
푬ퟎ − 푬ퟎ − ퟒ푬ퟎ푹푻풆ퟎ
(3)
푻풃
=
ퟐ푹
The TSADT and Tb values of DCBNT are 217.9 ℃ and 218.7 ℃
respectively, higher than that of commonly used explosives like
FOX-7(206.0 and 207.1 ℃).21 and CBNT (207.4 ℃ and 214.2 ℃),31
which indicates DCBNT has the higher resistance to heat and better
thermal safety than CBNT and TOX-7 under the same condition.
Moreover, the values of TSADT and Tb over 210 ℃ mean that
DCBNT has good thermal stability.
Fig. 5 DSC curves for DCBNT. Heating rate (℃ min-1): (a) 5, (b) 10,
(c) 15, (d) 20.
The calculated results using both methods include linear
correlation coefficient rK and rO are shown Table 3. It can be found
that the exothermic peak Tp shifts to higher temperatures as the
Safety and detonation properties
Detonation velocity (υD) and detonation pressure (P) were
heating rate increases and the good linear correlation coefficients are important parameters of energetic properties. The detonation
0.9922(rK) and 0.9927(rO) respectively, which are very close to 1. It velocity (υD) and the detonation pressure (P) of DCBNT were
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evaluated using EXPLO5 (v6.02) based on the measured ambient (EA). The solubility results are listed in Table 5 andVsieowluAbrtiicliletyOntleinset
temperature density (1.780 g cm-3) and the calculated heat of device diagram is shown in SI.
DOI: 10.1039/C8NJ05416A
formation(ΔfH). The ΔfH of DCBNT was calculated by the
isodesmic reaction approach using Gaussian 03 (Revision D.01)
suite program and was estimated to be 528.1 kJ mol-1 (see SI), which
was first reported. As shown in Table 4, the calculated detonation Table 5. Solubility of DCBNT in various solvents at 25 ℃
velocity and detonation pressure of DCBNT are 9235 m s-1 and 31.7
Sovent
DMSO
Water
EtOH
BL
DEF
Chloroform
GPa, respectively. The detonation velocity is quite similar to that of
HMX (9221 m s-1) and much superior to those of TATB (8114 m s-
1), RDX (8878 m s-1) and LLM-105 (8560 m s-1). Due to the
relatively low OB (51.38%), the detonation pressure of DCBNT
(31.7 GPa) is lower than those that listed in the Table 4 but is
comparable to TATB (32.4 GPa). This exhibits DCBNT has superior
detonation performance.
Sensitivity should be necessarily investigated because it is closely
linked with the safe handling and applying of explosives. Results are
shown in Table 4 and showed that the impact sensitivity of DCBNT
is very low (IS>40 J and H50 =90 cm), which are comparable to
CBNT, LLM-105 and FOX-7, meanwhile much lower than typical
nitroamine explosives like HMX and RDX (32 cm and 26 cm) and
TKX-50 (41 cm). The friction sensitivity of DCBNT is slightly
higher than that of CBNT, but far lower than RDX and HMX, these
attributes to the wave-like chain crystal structure with π-π stacking
interaction.39, 43-44 Additionally, DCBNT has higher decomposition
temperature (232 ℃) than CBNT (222 ℃), RDX (210 ℃), TKX-50
(221 ℃) and FOX-7 (220 ℃), which means that it has better thermal
stability. So, DCBNT can serve as a promising candidates for
RDX.11
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Solubility
(mg/100mL
solvent)
670
75
35
24
17
<15
DMF
-
Solvent
Dioxane
<15
EA
Acetonitrile
<15
MeOH
<15
Acetone
<15
Solubility
(mg/100mL
solvent)
<15
Table 5 shows that DCBNT exhibits a relatively poor solubility in
these solvents. Though the solubility value of DCBNT in DMSO is
highest, the solubility is only 670 mg per 100ml DMSO at 25 ℃. By
construct, DCBNT exhibited a much lower solubility of below 15
mg per 100 ml in most organic solvents including chloroform,
dioxane, ethyl acetate, acetonitrile, methanol and acetone. Even in
water, DCBNT was only slightly soluble at 25 ℃ (about 1/90 of the
solubility in DMSO).
Conclusions
In this study, DCBNT was synthesized and fully characterized by
single-crystal X-ray diffraction (SXRD), FTIR, 1H NMR and 13C
NMR, and elemental analysis were also introduced to analyse its
structural characterization and composition. Thermal properties for
the title salt was determined by TG-DSC analysis as well as the
calculation of non-isothermal kinetic parameters. In addition,
detonation parameters (e.g. detonation velocity and pressure) of the
target compound were computed using EXPLO5 v6.02 based on the
calculated heat of formation and density. The results show that
DCBNT exhibits a density of 1.780 g cm-3 and calculated detonation
velocity and detonation pressure with 9234.87 m s-1 and 31.71 GPa,
respectively. DCBNT exhibited good thermal stabilities as the
decomposition peak temperatures were over 230 °C. The activation
energy was 258.37 kJ mol-1 and 253.70 kJ mol-1 calculated by
Kissinger’s method and Ozawa–Doyle’s method, respectively.
Impact and friction sensitivities were also tested, and the results
indicated that these salts both have low sensitivities (impact
sensitivity >40 J and friction sensitivity is 216 N). The high thermal
stability, low sensitivity toward impact and friction with the good
detonation properties make DCBNT a potential king of low-sensitive
high-energic explosive.
Table 4. Physicochemical and energetic properties of DCBNT and
comparison with TATB, RDX, HMX, CBNT, LLM-105 and FOX-
7,45 TKX-50.46
b
f
compound
TATB
ρa
Td
ΔfH
Pd
De
H50
FSg
ISh
OBi
1.94
360
210
279
222
232
221
-139.5
32.4
8114
320
26
32
89
90
41
>360
>60
-55.81
RDX
1.80
1.90
1.95
1.78
1.918
86.3
34.9
39.2
33.4
31.7
42.4
8878
9221
9317
9235
9698
120
120
195
216
-
7.5
7.5
38
-21.61
-21.62
-46.24
-51.38
-27.12
HMX
116.1
47c
CBNT
DCBNT
TKX-50
528.1c
446.6c
>40
20
28.
7
24.
7
LLM-105
FOX-7
1.91
1.88
342
220
-12.0
33.4
35.9
8560
9000
117
126
>360
>360
-37.04
-21.62
-188.9
[a]
[b]
[c]
Density measured by gas pycnometer (25 oC).
Decomposition temperature(onset).
[d]
Calculated molar enthalpy of formation. Detonation pressure (calculated with EXPLO5 v6.02).
[e]
[f]
[g]
Detonation velocity (calculated with EXPLO5 v6.02).
Impact sensitivity.47
Friction
sensitivity evaluated by a BAM friction tester. [h] Impact sensitivity evaluated by a standard BAM
[i]
fall-hammer.
Oxygen balance (based on CO2) for CaHbOcNd; 1600(c-2a-b/2)/MW
(MW=molecular weight).
Experimental
Solubility
CAUTION! All the compounds in every scheme should be handled
with extreme care, although no incidents occurred during preparation
and manipulation. Additional proper protective precautions like face
shield, leather coat, earthed equipment and shoes, Kevlar gloves
should be used when working with these compounds.
Knowledge the solubility of explosive in different solvents is
necessary for the purifying and application ， as well as preparing
high-quality crystals of explosive. This study measured the solubility
of DCBNT in 12 common solvents: water (H2O), dimethyl sulfoxide
(DMSO), N, N-diethylformamide (DEF), N, N-dimethylformamide
(DMF), 1,4-butyrolactone (BL), methanol (MeOH), ethanol (EtOH),
acetone, chloroform (TCM), dioxane, acetonitrile, ethyl acetate
Materials and Instrument
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65%.1H NMR(600 MHz, DMSO- ｄ6, 25 ℃) δ=6.19, V8ie.0w5Arptipclme O;n1l3ine
C
All reagents were purchased commercially and used without
DOI: 10.1039/C8NJ05416A
further purification. Distilled water was prepared in our laboratory
NMR(150 MHz, DMSO- ｄ6, 25℃) δ=151.07, 157.04, 160.71 ppm.
1
and used throughout. H and 13C spectra were recorded on a 400
IR (KBr): υ (cm-1) =3501(w), 3365(s), 3335(s), 3153(w), 3098(w),
3024(w), 2926(w), 2854(w), 2668(w), 1953(w), 1702(s), 1630(m),
1566(w), 1524(s), 1493(w), 1448(s), 1387(m), 1363(w), 1339(s),
1274(s), 1246(m), 1200(w), 1166(m), 1113(s), 1080(s), 1013(m),
972(s), 933(w), 869(m), 766(m), 739(w), 709(m), 639(m), 583(w),
546(w), 472(w), 443(m), 416(w). Anal. Calcd. for C6H18N18O6:
C,16.44; H, 4.11; N, 57.53; Found: C, 16.35; H, 4.08, N, 57.61.
MHz (Bruker AVANCE 400) or 600 MHz (Bruker AVANCE 600)
nuclear magnetic resonance spectrometer. Infrared (IR) spectra were
measured on SHIMADZU IRTracer-100 FT-IR spectrometer in the
range of 4000-400 cm-1 as KBr pellets at 25 ℃. Transmittance
values are qualitatively described as strong (s), medium (m) and
weak (w). Elemental analyses (C, H, N) were carried out on an
elemental analyzer (Vario EL Cube, Germany). TG and DSC
analysis were conducted on differential scanning calorimeter-thermal
gravity instrument (TGA/DSC2, METTLER TOLEDO STARe
system) at the heating rate of 10 ℃ min-1. Single crystal X-ray
diffraction data were tested in a Rigaku supernova Single X-ray
Diffractometer area detector (Mo Kα, 0.71073 Å). The solubility of
DCBNT was collected by the CrystalSCAN system (E1320, United
Kingdom He., Ltd.). The mass of the solid was weighted using an
analytical balance (CP225D, Sartorius, Germany) with the accuracy
of 10-4 g. The temperature of the mixture was controlled by
circulating oil solution from a thermostat (Huber CC1-505wl vpc55,
Germany) with an uncertainty of u(T) = 0.01 °C.
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X-ray crystallography
Suitable crystals were chosen and placed in a Rigaku supernova
Single X-ray Diffractometer area detector using graphite
monochromated Mo Kα radiation (λ= 0.71073 Å) at 293(2) K. Its
structures were solved by direct methods and successive Fourier
difference syntheses using the SHELXTL software suite. Hydrogen
atoms attached to oxygen were placed from difference Fourier maps
and were refined using riding model. Data collection parameters and
refinement statistics were given in Table 1.
Synthetic procedures
Acknowledgements
The synthetic routes to the target compounds are outlined in
Scheme 1 and Scheme 2.
This work was supported by the National Natural Science
Foundation of China (no. U13301067, no. 11302200).
Notes and references
Scheme 1 Synthesis of compound BNT.
1.
2.
3.
4.
5.
6.
A. A. Dippold, T. M. Klapotke, J Am Chem Soc, 2013, 135 (26),
9931-9938.
J. Tishkoff, M. Berman, Air Force basic research in propellants
and combustion., 2002.
M. Smiglak, Metlen, R.; Rogers, R. D., Acc. Chem. Res., 2007,
40, 1182-1192.
C. Zhang, Y. Shu, Y. Huang, X. Zhao, H. Dong, J. Phys. Chem. B,
2005, 109, 8978-8982.
D. M. Badgujar, M. B.Talawar, S. N. Asthana, P. P. Mahulikar, J
Hazard Mater, 2008, 151 (2-3), 289-305.
M. B. Talawar, R. Sivabalan, T. Mukundan, H. Muthurajan, A.
K. Sikder, B. R. Gandhe, A. S. Rao, J Hazard Mater, 2009, 161
(2-3), 589-607.
Scheme 2 Synthesis of compound DCBNT.
Bis[3-(5-amino-1,2,4-triazole)] (BNT): BNT was prepared
according to the literature procedure.27,33, 36
Preparation of carbonyl hydrazine hydrochloride: 3.69 g (41
mmol) carbohydrazide was added to 10 ml water, then added 25%
10ml hydrochloric acid (8.3 g, 224 mmol concentrated hydrochloric
acid, about 6.4 ml, diluted with water to 10 ml) when the
temperature raised to 70 °C. Dring via rotary evaporation method to
remove water, then 5.13 g white solid was obtained (melting point is
219.7 ℃).
Preparation of Dicarbohydrazide bis[3-(5-nitroimino-1,2,4-triazole)]:
5.8 g (22.7 mmol) BNT was dissolved in 30 ml water, then added
2M 30 ml NaOH 60 mmol dropwise, the mixture was stirred to
7.
8.
9.
H. Qiu, V. Stepanov, AR Di Stasio, T. Chou, W. Y. Lee, J Hazard
Mater, 2011, 185 (1), 489-493.
Y. Bayat, M. Eghdamtalab, V. Zeynali, Journal of Energetic
Materials, 2010, 28 (4), 273-284.
Q. Zhang, J. M. Shreeve, Chem Rev, 2014, 114 (20), 10527-74.
10. D. Fischer, T. M. Klapotke, J. Stierstorfer, Angew Chem Int Ed
Engl, 2014, 53 (31), 8172-8175.
11. H. Gao, J. M. Shreeve, Chem Rev, 2011, 111 (11), 7377-436.
12. Y. Y. Qu, Q. Zeng, J. Wang, Q. Ma, H. Z. Li, H. B. Li, G. Y. Zhang,
Chemistry, 2016, 22 (35), 12527-12532.
13. P. Yin, D. A. Parrish, J. M. Shreeve, Angew Chem Int Ed Engl,
2014, 53 (47), 12889-12892.
14. D. M. Hoffman, A. T. Propellants, Explosives, Pyrotechnics,
2009, NA-NA.
15. L. G. Christian, B. Robert, L. Philippe, Propellants, Explosives,
Pyrotechnics, 2004, 29 (6), 339-343.
dissolve completely. 5.2
g (41 mmol, 1: 1, mol) prepared
carbohydrazide hydrochloride were added to the reaction solution
when the temperature was raised to 70 °C, then a large amount of
white solid appeared. The resulting solution was refluxed 1.5 h, and
filtered while cool to give corresponding salt, which was washed
several times with cold water and dried in vacuo at 60 ℃. Yield:
6 | J. Name., 2012, 00, 1-3
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Page 7 of 8
New Journal of Chemistry
Please do not adjust margins
Journal Name
ARTICLE
1
2
3
4
5
6
7
8
9
16. V. M. Boddu, D. S. Viswanath, T. K. Ghosh, R. Damavarapu, J
View Article Online
DOI: 10.1039/C8NJ05416A
Hazard Mater, 2010, 181 (1-3), 1-8.
17. P. F. Pagoria, A. R. Mitchell, R. D. Schmidt, R. L. Simpson, F.
Garcia, J. W. Forbes, R. W. Swansiger, D. M. Hoffman, Report
UCRL-JC130518, Lawrence Livermore National Laboratory,
Livermore, CA, 1998.
18. T. D. Tran, P. F. Pagoria, D. M. Hoffman, J. L. Cutting, R. S. Lee,
R. L. Simpson, 33rd International Annual Conference, 2002.
19. M. Anniyappan, M. B. Talawar, G. M. Gore, S. Venugopalan, B.
R. Gandhe, J Hazard Mater, 2006, 137 (2), 812-819.
20. N. V. Latypov, M. Johansson, E. Holmgren, Organic Process
Research & Development, 2007, 11, 56-59.
21. K. Xu, J. Song, F. Zhao, H. Ma, H. Gao, C. Chang, Y. Ren, R. Hu, J
Hazard Mater, 2008, 158 (2-3), 333-339.
22. G. Singh, S. P. Felix, Combustion and Flame, 2003, 132 (3),
422-432.
23. C. Y. Zhang, Y. F. Cao, H. Z. Li, Y. Zhou, J. H. Zhou, T. Gao, H. B.
Zhang, Z. W. Yang, G. Jiang, CrystEngComm 2013, 15, 4003-
4014.
24. H. S. Dong and F. F. Zhou, High Energetic Explosives and
Relatives, Science Press, Beijing, 1994 and its revision,
Science City, Mianyang, Sichuan, 2005 (in Chinese).
25. T. M. Klapötke, C. M. Sabaté, Chem. Mater., 2008, 20, 3629-
3637.
26. T. M. Klapötke, C. M. Sabaté, Chem. Mater. 2008, 20, 1750-
1763.
27. A. A. Dippold, T. M. Klapotke, Chem Asian J, 2013, 8 (7), 1463-
1471.
28. H. Brand, P. Mayer, A. Schulz, J. J. Weigand, Angew Chem Int
Ed Engl, 2005, 44 (25), 3929-3932.
29. V. P. Sinditskii, S. A. Filatov, V. I. Kolesov, K. O. Kapranov, A. F.
Asachenko, Thermochimica Acta, 2015, 614, 85-92.
30. B. Yuan, Z. Yu, E. R. Bernstein, J Phys Chem A, 2015, 119 (12),
2965-2981.
31. X. C. Huang, T. Guo, M. Liu, Z. J. Wand, S. J. Qiu, Ningbo,
zhejiang, 2016; pp 235-245.
32. R. H. Wang, H. Y. Xu, Y. Guo, R. J. Sa, J. M. Shreeve, American
Chemical Society, 2010, 132, 11904-11905.
33. A. A. Dippold, T. M. Klapötke, N. Winter, European Journal of
Inorganic Chemistry, 2012, 2012 (21), 3474-3484.
34. T. Yang, Z. B. Zhang, J. G. Zhang, Zeitschrift für anorganische
und allgemeine Chemie, 2017, 643 (6), 413-419.
35. K. Karaghiosoff, T. M. Klapötke, P. Mayer, C. M. Sabaté, A.
Penger, J. M. Welch, Inorg. Chem., 2008, 47, 1007-1019.
36. C. Y. Zhang, X. Cao, B. Xiang, J. Phys. Chem. C, 2010, 114,
22684-22687.
37. M. M. Kuklja, S. N. Rashkeev, Appl. Phys. Lett., 2007, 90.
38. M. M. Kuklja, S. N. Rashkeev, Physical Review B, 2007, 75 (10).
39. Y. Ma, A. B. Zhang, C. H. Zhang, D. J. Jiang, Y. Q. Zhu, C. Y.
Zhang, Crystal Growth & Design, 2014, 14 (9), 4703-4713.
40. H. E. Kissinger, Anal Chem, 1969, 2060-2069.
41. C. D. Doyle, J. Appl. Polym. Sci, 1961, 5, 285-292.
42. T. Ozawa, Bul.l Chem. Soc. Jpn, 1965, 38, 1881-1883.
43. Y. Ma, A. Zhang, X. Xue, D. Jiang, Y. Zhu, C. Zhang, Crystal
Growth & Design, 2014, 14 (11), 6101-6114.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
44. G. Liu, H. Li, R. Gou, C. Zhang, Crystal Growth & Design, 2018.
45. Y. Wang, Y. Liu, S. Song, Z. Yang, X. Qi, K. Wang, Y. Liu, Q.
Zhang, Y. Tian, Nat. Commun, 2018, 9 (1), 2444.
46. N. Fischer, D. Fischer, T. M. Klapötke, D. G. Piercey, J.
Stierstorfer, J. Mater. Chem, 2012, 22 (38), 20418-20422.
47. Z. Xu, G. Cheng, H. Yang, X. Ju, P. Yin, J. Zhang, J. M. Shreeve,
Angew. Chem. Int. Ed. Engl, 2017, 56 (21), 5877-5881.
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DCBNT, a new compound, exhibits low friction and impact sensitivities, good thermal stability,
promising detonation pressure and detonation velocity.