Insensitive nitrogen-rich materials incorporating the nitroguanidyl functionality

Article abstract of DOI:10.1002/asia.201301242

A new class of nitroguanidylfunctionalized nitrogen-rich materials derived from 1,3,5-triazine and 1,2,4,5- tetrazine was synthesized through reactions between N-nitroso-N'-alkylguanidines and the hydrazine derivatives of 1,3,5-triazine or 1,2,4,5-tetrazine. These compounds were fully characterized using multinuclear NMR and IR spectroscopies, elemental analysis, and differential scanning calorimetry (DSC). The heats of formation for all compounds were calculated with Gaussian 03 and then combined with experimental densities to determine the detonation pressures (P) and velocities (D _v) of the energetic materials. Interestingly, some of the compounds exhibit an energetic performance (P and D_v) comparable to that of RDX, thus holding promise for application as energetic materials. Copyright

Full text of DOI:10.1002/asia.201301242

FULL PAPER
DOI: 10.1002/asia.201301242
Insensitive Nitrogen-Rich Materials Incorporating the Nitroguanidyl
Functionality
Qinghua Zhang, Chunlin He, Ping Yin, and Jean’ne M. Shreeve*[a]
Abstract: A new class of nitroguanidyl-
functionalized nitrogen-rich materials
derived from 1,3,5-triazine and 1,2,4,5-
tetrazine was synthesized through reac-
tions between N-nitroso-N’-alkylguani-
dines and the hydrazine derivatives of
1,3,5-triazine or 1,2,4,5-tetrazine. These
compounds were fully characterized
using multinuclear NMR and IR spec-
troscopies, elemental analysis, and dif-
ferential scanning calorimetry (DSC).
The heats of formation for all com-
pounds were calculated with Gaussian
03 and then combined with experimen-
tal densities to determine the detona-
tion pressures (P) and velocities (Dv)
of the energetic materials. Interestingly,
some of the compounds exhibit an en-
ergetic performance (P and Dv) com-
parable to that of RDX, thus holding
promise for application as energetic
materials.
Keywords: nitrogen heterocycles ·
nitrogen-rich materials · nitrogua-
nidyl functionality
· sensitivity ·
tetrazine · triazine
Introduction
High-nitrogen heterocycles represent a unique class of en-
ergetic molecules, which have recently attracted significant
interest in the fields of energetic materials. For some high-
nitrogen heterocyclic molecules, such as triazole,[6] tetra-
zole,[7] triazine,[8] and tetrazine,[9] most of their energy de-
rives from a combination of positive heats of formation and
generation of large volumes of environmentally benign ni-
trogen gas under decomposition with a high order of energy
release. Relative to traditional carbon-based energetic com-
pounds such as TNT and TATB, the energetic materials de-
rived from high-nitrogen heterocycles can offer some prom-
ising advantages, for example, relatively “greener” combus-
tion products, higher enthalpy of formation, and/or higher
energetic performance. Moreover, the high-nitrogen content
of the energetic molecules usually means higher molecular
densities, and the low hydrogen and carbon content makes
the achievement of a good oxygen balance of these materi-
als much easier. In this sense, the high-nitrogen heterocycles
have been considered as very promising building blocks for
the construction of ideal HEDMs, in which the 1,3,5-triazine
and 1,2,4,5-tetrazine rings are among the typical examples
The design and synthesis of new compounds known as high-
energy density materials (HEDMs) has been the focus of
our group for the past decade.[1–3] In the pursuit of new
HEDMs, current interest not only focuses on the energetic
properties of the target material (density, detonation veloci-
ty, and detonation pressure) but also concerns about the en-
vironment and safety issues of the material, including the
“greenness” of explosion products, their toxicity to human
health, and their sensitivity toward heat, shock, friction, and
electrostatic discharge. With this background, considerable
effort has been devoted to developing new-generation
HEDMs with integrated properties including high density,
good thermal stability, high detonation velocity and pres-
sure, low sensitivity, environmentally benign explosion prod-
ucts, low cost, and ease of production in sizeable amounts.
To date, numerous HEDMs with new structures have been
designed and synthesized.[4,5] Unfortunately, for most devel-
oped HEDMs, it is very difficult to simultaneously meet the
needs of all of the following criteria, that is, high density,
high energy, low sensitivity to thermal shock and friction,
and environmentally benign nature, to list a few. Therefore,
the development of new environmentally benign HEDMs
with excellent integrated performance must be one of the
main goals in future energetic materials research.
À
À
due to their high-energy N N and C N bonds, as well as
their intense ring strain. From the viewpoint of designing
high-performance energetic materials, the most widely used
strategy is to incorporate some energy-containing groups
such as nitro, azido, azo, or N-oxide into the molecular
backbone of the high-nitrogen heterocycles, in particular the
1,3,5-triazine or 1,2,4,5-tetrazine ring. By virtue of this strat-
egy, several tetrazine- or triazine-derived energetic materials
have been reported (Scheme 1).[10,11] For example, 3,6-diazi-
do-1,2,4,5-tetrazine (1) displays a very high heat of forma-
tion (about 6709 kJkgÀ1),[12] and 4,4’6,6’-tetraazido-2,2’-azo-
1,3,5-triazine (2)[8b] has a heat of formation of 6164 kJkgÀ1
(Scheme 1). Although these compounds are highly energetic
[a] Dr. Q. Zhang, Dr. C. He, Dr. P. Yin, Prof. Dr. J. M. Shreeve
Department of Chemistry, University of Idaho
Moscow, ID 83844-2343 (USA)
Fax : (+1)208-885-9146
E-mail: jshreeve@uidaho.edu
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Jean’ne M. Shreeve et al.
Scheme 1. Examples of some high-nitrogen compounds based on 1,2,4,5-
tetrazine or 1,3,5-triazine.
due to their positive heats of formation, the characteristics
of high sensitivity significantly limit their application poten-
tial for use on a large scale.
In our continuing effort to seek new energetic materials,
here we present our attempts at designing and synthesizing
a series of high-nitrogen triazine- or tetrazine-derived com-
pounds through the strategy of incorporating an energetic
nitroguanidyl group into the backbone of the 1,3,5-triazine
or 1,2,4,5-tetrazine ring. For these new compounds, the high
nitrogen content of both the nitroguanidyl group and the
molecular backbone (i.e., 1,2,4,5-tetrazine or 1,3,5-triazine
ring) is expected to contribute higher crystal density, higher
heats of formation, and environmentally benign decomposi-
tion products (N2), and thereby to result in an excellent det-
onation performance. Meanwhile, some significant charac-
teristics of the triazine or tetrazine ring, for instance, the
high thermal stability as well as the low sensitivity toward
heat, shock, friction, and electrostatic discharge, are expect-
ed to endow the target materials with excellent safety prop-
erties.
Scheme 2. Synthesis of nitroguanidyl-functionalized triazine derivatives
5–7.
Results and Discussion
It is known that N-nitroso-N’-alkylguanidines can readily
react with alkylamines to eliminate the nitrosamino group
and form nitroguanidyl-functionalized alkylamines.[13] Thus,
we began our synthesis of N-methyl-N-nitroso-N’-nitrogua-
nidine (4), which can provide a nitroguanidyl group. The
commercially available nitroguanidine was first reacted with
methylamine to form methyl-N’-nitroguanidine in good
yield (84%) and then was nitrosated by sodium nitrite in
the presence of 70% nitric acid to yield 4.[13] The aqueous
solutions of hydrazine derivatives of 1,3,5-tetrazine-based
compounds can react at or below room temperature with 4
to yield the nitroguanidyl-functionalized 1,3,5-tetrazine-de-
rived products (5–7) in good yields (Scheme 2).
With three nitroguanidyl-functionalized triazine deriva-
tives in hand, we turned our attention to the preparation of
nitroguanidyl-functionalized 1,2,4,5-tetrazine derivatives. At
room temperature, the aqueous suspension of hydrazine de-
rivatives of 1,2,4,5-tetrazine can react with 4 to give the ni-
troguanidyl-functionalized tetrazine compound 8 in high
yield (Scheme 3). Moreover, for the purpose of comparison,
two acyclic carbonyl-bridged nitroguanidyl derivatives (9–
10) were also synthesized using the same synthetic method-
ology (Scheme 3). Note that the attempts of reactions be-
tween the amino derivatives of 1,3,5-triazine (e.g., 2,4,6-tria-
mino-1,3,5-triazine) or the amino derivatives of 1,2,4,5-tetra-
Scheme 3. Synthesis of nitroguanidyl-functionalized tetrazine derivative 8
and acyclic carbonyl-bridged nitroguanidyl derivatives 9–10.
zine (e.g., 3,6-diamino-1,2,4,5-tetrazine) and 4 did not result
in the corresponding nitroguanidyl-functionalized deriva-
tives, probably due to the decreased reactivity of the amino
group relative to the hydrazine group.
The structures of the six new compounds 5–10 are sup-
ported by IR, 1H NMR, 13C NMR, and 15N NMR spectro-
scopic data as well as elemental analysis. In the 1H NMR
spectra, the hydrogen resonances of the -NH-NH- groups,
which are attached to the nitroguanidyl group, appeared at
low field (8.0–10.5 ppm). In the 13C NMR spectra, due to the
strong electron-withdrawing effect of the nitroamino group,
the carbon resonance for the nitroguanidyl group was
always observed as a weak peak in the range of 161–
162 ppm. The 15N NMR spectra of some of the new com-
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For energetic materials, thermal stability and density are
two of the most important properties. In this work, except
for the compound 6 (Td =1958C), the decomposition tem-
perature (Td) of all other nitroguanidyl-functionalized com-
pounds is higher than 2008C (Table 1), thus indicating that
these compounds are promising energetic materials that ex-
hibit good thermal stability. Of these, 5 has the highest ther-
mal stability, Td =2608C, which is higher than that of RDX
(2308C). The densities of these new nitroguanidyl-function-
alized compounds ranged between 1.66 and 1.81 gcmÀ1, of
which 8 exhibits the highest density at 1.81 gcmÀ3, which is
very close to that of RDX (1.82 gcmÀ3).
To obtain the optimized structures and frequency analyses
of the new compounds 5–10, density functional theory calcu-
lations were performed at the level of Becke three-parame-
ter Lee–Yang–Parr (B3LYP) parameters up to the 6-31G+
(d,p) basis sets using Gaussian 03. All of the optimized
Figure 1. 15N NMR spectra of 5 and 6.
pounds were measured in
[D6]DMSO solvent, and chemi-
cal shifts are given with respect
to CH3NO2 as external stan-
dard. The 15N NMR spectra of
compounds 5 and 6 are given in
Figure 1. The strong signals as-
signed to the nitro groups (N1)
Table 1. Physical properties of nitroguanidine-functionalized energetic compounds.
[a]
[d]
Compd Mw
[gmolÀ1
N%
A
Td
1[b]
[gcmÀ3
DHf[c]
[kJmolÀ1
DHf[c]
[kJgÀ1
Dv
[msÀ1
P[e]
A
IS[f]
FS[g] OB[h]
G
]
G
]
E
]
G
]
N
]
[N]
[%]
5
6
7
8
9
10
228.17
432.28
656.42
316.20
264.16
322.20
222.12
296.16
61.39
58.32
59.75
62.02
53.02
52.17
37.84
37.84
260
195
201
201
206
200
230
287
1.70
1.74
1.71
1.81
1.66
1.75
1.82
1.91
172.4
577.8
597.7
733.1
107.7
7.0
0.76
1.34
0.91
2.32
0.41
0.02
0.42
0.35
7672
8378
7812
8884
8138
8263
8977
9320
22.2
28.7
23.9
33.7
26.5
27.9
35.2
39.6
>40 360
>40 360
>40 360
À42.1
À22.2
À24.4
À20.2
À12.1
À14.9
0
32
120
>40 360
>40 360
7.4
7.4
appear
at
À12.25
and RDX
HMX
92.6
104.8
120
120
0
À12.22 ppm for 5 and 6, respec-
tively. The signal of the N2
atom, which is directly attached
to the nitro group, can be as-
signed to the resonances at the
[a] Thermal decomposition temperature under nitrogen gas (determined by the DSC exothermal peak,
58CminÀ1). [b] Density measured by a gas pycnometer (258C). [c] Heat of formation calculated with Gaussi-
an 03. [d] Detonation velocity calculated with EXPLO 5.05. [e] Detonation pressure calculated with EXPLO
5.05. [f] Impact sensitivity measured by BAM drop hammer; [g] Friction sensitivity measured by a BAM fric-
tion tester. [h] Oxygen balance (%) for CaHbNcOd: OB (%)=1600ꢂ(dÀaÀb/2)/Mw (based on carbon monox-
ide).
second
lowest
field
(À144.24 ppm and À144.14 ppm
for 5 and 6, respectively) due to
the presence of the nitro group. Next, the resonance signals
in the range of À200 to À207 ppm are assigned to the nitro-
gen signal from the triazine ring (N6 and N7 of 5, and N6 of
6), probably due to the more electron-deficient character of
the nitrogen atom in the triazine ring than the nitrogen
atoms in the -NH- groups and the -NH2 groups. For 5, the
assignment of the resonance peaks of N6 and N7 can be fur-
ther determined by the relative abundance of the resonance
signal since there are two N6 atoms and only one N7 atom
in the triazine ring. The nitrogen signal of the amino groups
that are attached to the triazine ring or from the nitrogua-
nidyl group can be assigned to the resonances at the highest
field (ranging from À295 to À298 ppm) due to the electron-
rich nature, while the N4 and N5 signals from the -NH-NH-
groups are observed at a relatively lower field than the sig-
nals of -NH2 groups. However, it is difficult to distinguish
further assignments between N4 and N5 signals. It should be
pointed out that the 15N NMR analysis of nitroguanidyl-
functionalized tetrazine derivatives is difficult to achieve,
mainly due to poor solubility in most deuterated solvents
(even in [D6]DMSO).
structures were characterized to be true local energy
minima on the energy potential surface (ESP) without imag-
inary frequencies. The electrostatic potential (ESP) of the
three energetic compounds 6–8 was computed at the opti-
mized structure at the B3LYP/6-31G+(d,p) level of theory.
Figure 2 shows the ESP for the 0.001 electron/bohr3 isosur-
face of the electron density evaluated at the B3LYP level of
theory. It has recently been reported by Politzer, Murray
et al.,[14] and extensively used by Rice et al.,[15] that the pat-
terns of the computed ESP on the surface of molecules in
general can be related to the sensitivity of the bulk material.
According to Politzerꢁs theory,[14] the impact sensitivity of an
energetic compound can be expressed as a function of the
extent of this anomalous reversal of the strengths of the pos-
itive and negative surface potentials. From the ESP of com-
pounds 6–8, the regions of positive potential and negative
potential are difficult to differentiate by the color, that is, no
atypical imbalance related to the impact sensitivities can be
observed between stronger positive regions and weaker neg-
ative ones. This is in good accord with the experimental re-
sults of relatively high impact sensitivity and friction sensi-
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Jean’ne M. Shreeve et al.
velocity (8884 msÀ1), which is comparable to that of RDX
(8977 msÀ1). The detonation pressures range between 22.9
and 33.7 GPa, in which the highest P value of 8 (33.7 GPa)
is slightly lower than that of RDX (35.2 GPa). More impor-
tantly, most of these new energetic compounds exhibited
low sensitivities toward impact and friction, that is, the IS
values are >40 J and the FS values are 360 N, further high-
lighting their likely application potential. Among them,
compound 8 has an IS value of 32 J and an FS value of
120 N, respectively. The oxygen balance (OB) is the index of
the deficiency or excess of oxygen in a compound required
to convert all carbon atoms into carbon monoxide and all
hydrogen atoms into water. In this work, for a compound
with the molecular formula of CaHbNcOd, the oxygen bal-
ance is calculated as follows: OB (%)=1600ꢂ(dÀaÀb/2)/
Mw (Table 1). Unfortunately, the six new energetic com-
pounds exhibited negative OB values ranging from À12.1%
to À42.1%, mainly due to the relatively higher carbon and
hydrogen content in the molecules.
Conclusions
In summary, a new class of nitroguanidyl-functionalized tria-
zine and tetrazine derivatives has been synthesized and fully
characterized. All the nitrogen-rich compounds derived
from 1,3,5-triazine and 1,2,4,5-tetrazine showed good ther-
mal stabilities and low impact sensitivities. Of these, 8 exhib-
ited an energetic performance comparable to that of RDX
(i.e., 33.7 GPa for P and 8884 msÀ1 for Dv for 8 versus
35.2 GPa for P and 8977 msÀ1 for Dv for RDX, respective-
ly). In addition to the energetic properties, all the energetic
materials are impact-insensitive, further highlighting their
application potentials as new-generation insensitive energet-
ic materials.
Figure 2. Optimized structures and electrostatic potential surfaces of
compounds 6–8 (B3LYP/6-31G+(d,p), 0.001 electron/bohr3 isosurface,
energy values À0.2 to +0.1H). The red and blue regions of the ruler
(from top to bottom) indicate regions of more negative and positive
charges, respectively.
tivity of these three compounds (Table 1). The heats of for-
mation of 5–10 were calculated with Gaussian 03 by using
the method of isodesmic reactions (Scheme 4). From
Table 1, the nitroguanidyl-functionalized tetrazine com-
pound (8) exhibited very high positive heats of formation
(2.32 kJgÀ1). In comparison with most of the nitroguanidyl-
functionalized tetrazine or triazine derivatives (6–8), the
heats of formation of the carbonyl-bridged nitroguanidyl de-
rivatives (9–10) are much lower (i.e., 0.41 kJgÀ1 and
0.02 kJgÀ1, respectively), likely due to the absence of a high
ring strain energy deriving from the triazine or tetrazine
rings.
By using the calculated heats of formation and the experi-
mentally measured densities, the detonation pressures (P)
and velocities (Dv) of 5–10 were calculated based on tradi-
tional Chapman–Jouget thermodynamic detonation theory
using EXPLO 5.05 (Table 1). For these new nitroguanidyl-
functionalized compounds, the calculated detonation veloci-
ties lie in the range between 7672 and 8884 msÀ1, most of
which are remarkably higher than that of TATB
(8114 msÀ1). Among them, 8 exhibits the highest detonation
Experimental Section
Safety Precautions
Although none of the compounds described herein has exploded or deto-
nated in the course of this research, these materials should be handled
with extreme care using the best safety practices. Manipulation must be
carried out in a hood behind a safety shield. Leather gloves must be
worn.
General Methods
1H, 13C, and 15N NMR spectra were recorded on 300 MHz (Bruker
AVANCE 300) and 500 MHz (Bruker AVANCE 500) nuclear magnetic
resonance spectrometers operating at 300.13, 75.48, and 50.69 MHz, re-
spectively, by using [D6]DMSO as the solvent and locking solvent unless
otherwise stated. Chemical shifts in 1H and 13C NMR spectra are report-
ed relative to Me4Si and those in 15N NMR spectra relative to MeNO2.
The decomposition temperatures were determined by a differential scan-
ning calorimeter (TA Instruments, model Q 10) at a scan rate of 58C
minÀ1. Samples were placed in a 40 mL hermetically sealed aluminum pan
with a pinhole at the top of the pan. IR spectra were recorded using KBr
pellets on a BIORAD model 3000 FTS spectrometer. Densities of the
compounds were determined at room temperature by employing a Micro-
meritics AccuPyc 1330 gas pycnometer. Elemental analyses were carried
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Jean’ne M. Shreeve et al.
Synthesis of 5
2,4-Diamino-6-chloro-1,3,5-triazine
was readily synthesized according to
a method previously reported.[16] 2,4-
Diamino-6-hydrazinyl-1,3,5-triazine
was also obtained by
a reported
method.[17] Hydrazine hydrate (4.32 g,
4.2 mL, 86.4 mmol) was added drop-
wise to a suspension of 2,4-diamino-6-
chloro-1,3,5-triazine (2.5 g, 17.7 mmol)
in water (20 mL). The mixture was
stirred overnight at 858C. The white
solid was filtered off, washed with
water (300 mL), and dried under high
vacuum to afford pure 2,4-diamino-6-
hydrazinyl-1,3,5-triazine (72%, 1.80 g).
The synthesis of 5 is as follows: N-
methyl-N-nitroso-N’-nitroguanidine (4,
0.34 g, 2.2 mmol) was added to an
aqueous solution (25 mL) of 2,4-diami-
no-6-hydrazinyl-1,3,5-triazine (0.282 g,
2 mmol) at room temperature. The
mixture was stirred at room tempera-
ture for 18 h. After completion of the
reaction, the resulting precipitate was
filtered off, washed with cold water
(10 mL), and dried to give 5 as a pale
yellow powder (83%, 0.38 g). Td =
2608C; IR (KBr): n˜ =3351, 3231, 3099,
1656, 1545, 1487, 1368, 1318, 1242,
1067, 1028, 807, 638, 519, 426 cmÀ1
;
1H NMR: d=9.68 (s, 1H, -NH-), 8.49
(s, 2H, -NH2), 8.08 (s, 1H, -NH-),
6.41 ppm (s, 4H, -NH2); 13C NMR: d=
167.7, 167.2, 161.5 ppm; elemental
analysis (%) calcd for C4H8N10O2
(228.17): C 21.06, H 3.53, N 61.39;
found: C 21.00, H 3.61, N 60.15.
Synthesis of 6
Pure 2,4,6-trihydrazinyl-1,3,5-triazine
was readily synthesized according to
Scheme 4. Isodesmic reactions for compounds 5–10.
a method previously reported.[18] The
synthesis of 6 is as follows: N-methyl-
out using an Exeter CE-440 elemental analyzer. Impact and friction sen-
sitivity measurements were made using a standard BAM drop hammer
and a BAM friction tester.
N-nitroso-N’-nitroguanidine (4) (0.51 g, 3.3 mmol) was added to an aque-
ous solution (50 mL) of 2,4,6-trihydrazinyl-1,3,5-triazine (0.171 g,
1 mmol) at room temperature. The mixture was stirred at room tempera-
ture for 18 h. After completion of the reaction, the resulting precipitate
was filtered off, washed with cold water (50 mL), and dried to give 6 as
a pale yellow powder (78%, 0.34 g). Td =1958C; IR (KBr): n˜ =3416,
3309, 3241, 2932, 1642, 1584, 1539, 1429, 1384, 1294, 1053, 955, 812, 710,
Preparation of N-Methyl-N’-nitroguanidine (4)
First, N-methyl-N’-nitroguanidine was synthesized according to previous-
ly reported methods.[13] An alkaline solution of nitroguanidine (0.1 mol,
10.4 g) in 30 mL of water containing KOH (0.215 mol, 12 g) was pre-
pared. The solution was heated to 408C to dissolve the nitroguanidine
and then methylamine hydrochloride (0.2 mol, 13.5 g) was added with
stirring. The temperature was increased to 598C and maintained at 59–
618C for 30 min. The resulting clear solution was cooled in an ice–water
bath to 5–68C. The white precipitate was filtered off, washed with cold
water (30 mL), and dried in air to yield N-methyl-N’-nitroguanidine
(10.0 g, 84.7%) as a white solid (m.p. 151–1548C). Then, N-methyl-N’-ni-
troguanidine (0.085 mol, 10.0 g) was dissolved in H2O (100 mL) by the
addition of 30 mL 70% HNO3. The resulting solution was cooled in an
ice bath and NaNO2 (0.18 mol, 12.4 g) dissolved in water (20 mL) was
added over a period of 5 min. The mixture was stirred for 30 min, and
then the resulting precipitate was filtered and washed with cold water to
afford 4 (8.75 g) as a yellow crystalline product (m.p. 112–1138C). The
612, 470 cmÀ1 1H NMR: d=9.80 (s, 1H, -NH-), 9.33 (s, 1H, -NHÀ), 8.56
;
(s, 1H, -NH-), 8.15 ppm (s, 1H, -NH); 13C NMR: d=167.9, 161.4 ppm; el-
emental analysis (%) calcd for C6H12N18O6 (432.28): C 16.67, H 2.80, N
58.32; found: C 17.08, H 3.35, N 57.12.
Synthesis of 7
Bis-(4,6-dihydrazino-[1,3,5]triazin-2-yl)-diazene was synthesized accord-
ing to a method previously reported.[19] The synthesis of 7 is as follows:
N-methyl-N-nitroso-N’-nitroguanidine (4, 4.2 mmol, 0.62 g) was added to
an aqueous solution (50 mL) of bis-(4,6-dihydrazino-[1,3,5]triazin-2-yl)-
diazene (0.31 g, 1 mmol) at room temperature. The mixture was stirred at
room temperature for 18 h. After completion of the reaction, the result-
ing precipitate was filtered off, washed with cold water (50 mL), and
dried to give the 7 as a yellow powder (74%, 0.49 g). Td =2018C; IR
(KBr): n˜ =3302, 1590, 1539, 1499, 1376, 1277, 1056, 812, 552, 474 cmÀ1
;
1
structure of 4 was confirmed by H NMR spectroscopic analysis, which is
1H NMR: d=9.80 (s, 1H, -NH-), 9.33 (s, 1H, -NHÀ), 8.56 (s, 1H, NH),
8.15 ppm (s, 1H, NH); 13C NMR: d=167.5, 161.4 ppm; elemental analysis
agreement with the reported data.[14]
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Jean’ne M. Shreeve et al.
(%) calcd for C10H16N28O8 (656.42): C 18.30, H 2.46, N 59.75; found: C
18.61, H 3.03, N 56.40.
Chem. Soc. 2010, 132, 11904–11905; c) S. Garg, H. Gao, Y.-H. Joo,
D. A. Parrish, Y. Huang, J. M. Shreeve, J. Am. Chem. Soc. 2010, 132,
8888–8890; d) V. Thottempudi, H. Gao, J. M. Shreeve, J. Am.
Chem. Soc. 2011, 133, 6464–6471.
Synthesis of 8
[4] a) T. M. Klapçtke, J. Stierstorfer, A. U. Wallek, Chem. Mater. 2008,
20, 4519–4530; b) T. M. Klapçtke, C. Petermayer, D. G. Piercey, J.
Stierstorfer, J. Am. Chem. Soc. 2012, 134, 20827–20836; c) K.
Banert, S. Richter, D. Schaarschmidt, H. Lang, Angew. Chem. 2013,
125, 3583–3586; Angew. Chem. Int. Ed. 2013, 52, 3499–3502.
[5] a) Y. C. Li, C. Qi, S. H. Li, H. J. Zhang, C. H. Sun, Y. Z. Yu, S. P.
Pang, J. Am. Chem. Soc. 2010, 132, 12172–12173; b) T. M. Klapçtke,
J. Stierstorfer, J. Am. Chem. Soc. 2009, 131, 1122–1134.
[6] a) A. A. Dippold, T. M. Klapçtke, Chem. Eur. J. 2012, 18, 16742–
16753; b) S. Garg, J. M. Shreeve, J. Mater. Chem. 2011, 21, 4787–
4795; c) G. H. Tao, B. Twamley, J. M. Shreeve, J. Mater. Chem. 2009,
19, 5850–5854; d) C. Qi, S. Li, Y. Li, Y. Wang, X. Chen, S. Pang, J.
Mater. Chem. 2011, 21, 3221–3225.
3,6-Dihydrazino-1,2,4,5-tetrazine (1 mmol) was synthesized according to
a method previously reported.[20] The synthesis of 8 is as follows: N-
methyl-N-nitroso-N’-nitroguanidine (4) (0.34 g, 2.2 mmol) was added to
an aqueous solution (50 mL) of 3,6-dihydrazino-1,2,4,5-tetrazine (0.142 g,
1 mmol) at room temperature. The mixture was stirred at room tempera-
ture for 18 h. After completion of the reaction, the resulting precipitate
was filtered off, washed with cold water (50 mL), and dried to give 8 as
an orange powder (86%, 0.27 g). Td =2018C; IR (KBr): n˜ =3379, 3218,
1620, 1603, 1578, 1521, 1433, 1321, 1282, 1187, 1063, 1026, 949, 762, 570,
471 cmÀ1 1H NMR: d=10.10 (s, 1H, -NH-), 9.94 (s, 1H, -NH-), 8.62 (s,
;
1H, -NH-), 8.43 ppm (s, 1H, -NH-); 13C NMR: d=162.2, 161.8 ppm; ele-
mental analysis (%) calcd for C4H8N14O4 (316.20): C 15.19, H 2.55, N
62.02; found: C 15.28, H 2.89, N 62.74.
[7] a) T. Abe, Y.-H. Joo, G. Tao, B. Twamley, J. M. Shreeve, Chem. Eur.
J. 2009, 15, 4102–4110; b) M-J. Crawford, T. M. Klapçtke, F. A.
Martin, C. M. Sabatꢃ, M. Rusan, Chem. Eur. J. 2011, 17, 1683–1695;
c) H. Gao, Y. Huang, C. Ye, B. Twamley, J. M. Shreeve, Chem. Eur.
J. 2008, 14, 5596–5603.
[8] a) Y. Huang, Y. Zhang, J. M. Shreeve, Chem. Eur. J. 2011, 17, 1538–
1546; b) M. V. Huynh, M. A. Hiskey, E. L. Hartline, D. P. Montoya,
R. Gilardi, Angew. Chem. 2004, 116, 5032–5036; Angew. Chem. Int.
Ed. 2004, 43, 4924–4928.
[9] a) D. E. Chavez, M. A. Hiskey, R. D. Gilardi, Angew. Chem. 2000,
112, 1861–1863; Angew. Chem. Int. Ed. 2000, 39, 1791–1793; b) H.
Gao, R. Wang, B. Twamley, M. A. Hiskey, J. M. Shreeve, Chem.
Commun. 2006, 4007–4009; c) T. M. Klapçtke, A. Preimesser, S.
Schedlbauer, J. Stierstorfer, Cent. Eur. J. Energ. Mater. 2013, 10,
151–170.
Synthesis of 9
N-Methyl-N-nitroso-N’-nitroguanidine (4, 0.34 g, 2.2 mmol) was added to
an aqueous solution (50 mL) of carbohydrazide (0.09 g, 1 mmol) at room
temperature. The mixture was stirred at room temperature for 18 h.
After completion of the reaction, the resulting precipitate was filtered
off, washed with cold water (50 mL), and dried to give 9 as a white
powder (69%, 0.18 g). Td =2068C; IR (KBr): n˜ =3389, 3290, 3229, 3131,
1649, 1562, 1427, 1364, 1297, 1246, 1177, 1090, 1055, 957, 773, 680, 565,
473 cmÀ1 1H NMR: d=9.58 (s, 1H, -NH-), 8.94 (s, 1H, -NH-), 8.67 (s,
;
1H, NH), 8.15 ppm (s, 1H, NH); 13C NMR: d=161.6, 156.7 ppm; ele-
mental analysis (%) calcd for C3H8N10O5 (264.16): C 13.64, H 3.05, N
53.02; found: C 13.43, H 3.02, N 51.52.
Synthesis of 10
[10] a) T. M. Klapçtke, F. A. Martin, J. Stierstorfer, Angew. Chem. 2011,
123, 4313–4316; Angew. Chem. Int. Ed. 2011, 50, 4227–4229; b) C.
Ye, H. Gao, J. A. Boatz, G. W. Drake, B. Twamley, J. M. Shreeve,
Angew. Chem. 2006, 118, 7420–7423; Angew. Chem. Int. Ed. 2006,
45, 7262–7265; c) M. A. Petrie, J. A. Sheehy, J. A. Boatz, G. Rasul,
G. K. S. Prakash, G. A. Olah, K. O. Christe, J. Am. Chem. Soc. 1997,
119, 8802–8808.
[11] a) D. E. Chavez, M. A. Hiskey, R. D. Gilardi, Org. Lett. 2004, 6,
2889–2891; b) D. E. Chavez, B. C. Tappan, M. A. Hiskey, S. F. Son,
H. Harry, D. Montoya, S. Hagelberg, Propellants Explos. Pyrotech.
2005, 30, 412–417.
N-Methyl-N-nitroso-N’-nitroguanidine (4, 0.34 g, 2.2 mmol) was added to
an aqueous solution (50 mL) of 1,2-bis(hydrazinocarbonyl)hydrazine
(0.148 g, 1 mmol) at room temperature. The mixture was stirred at room
temperature for 18 h. After completion of the reaction, the resulting pre-
cipitate was filtered off, washed with cold water (50 mL), and dried to
give 10 as a white powder (71%, 0.23 g). Td =2008C; IR (KBr): n˜ =3397,
3322, 3237, 1638, 1583, 1526, 1414, 1332, 1274, 1242, 1141, 1055, 1089,
781, 744, 624, 582, 469 cmÀ1 1H NMR: d=9.61 (s, 1H, -NH-), 8.97 (s,
;
1H, -NH-), 8.76 (s, 1H, -NH-), 8.53 (s, 1H, NH), 7.85 ppm (s, 1H, NH);
13C NMR: d=161.7, 157.5 ppm; elemental analysis (%) calcd for
C4H10N12O6 (322.2): C 14.91, H 3.13, N 52.17; found: C 14.92, H 3.35, N
50.27.
[12] M. H. V. Huynh, M. A. Hiskey, D. E. Chavez, D. L. Naud, R. D. Gi-
lardi, J. Am. Chem. Soc. 2005, 127, 12537–12543.
[13] A. F. McKay, G. F. Wright, J. Am. Chem. Soc. 1947, 69, 3028–3030.
[14] a) Computational Characterization of Energetic Materials. P. Politzer,
J. S. Murray in Paulingꢀs Legacy: Modern Modelling of the Chemical
Bond (Eds.: Z. B. Maksic, W. J. Orville-Thomas), Theoretical and
Computational Chemistry 6, Elsevier, New York, 1999, pp. 347–363;
b) P. Politzer, J. S. Murray, J. M. Seminario, P. Lane, M. E. Grice,
M. C. Concha, J. Mol. Struct. 2001, 573, 1–10; c) J. S. Murray, M. C.
Concha, P. Politzer, Mol. Phys. 2009, 107, 89–97.
Acknowledgements
The authors gratefully acknowledge the support of ONR (N00014-12-1-
0536 and N00014-11-AF-0-0002).
[15] a) B. M. Rice, J. J. Hare, J. Phys. Chem. 2002, 106, 1770–1783; b) E.
GçkÅınar, T. M. Klapçtke, M. P. Kramer, J. Phys. Chem. A 2010,
114, 8680–8686; c) Computational Aspects of Nitrogen-Rich
HEDMs. B. M. Rice, E. F. C. Byrd, W. D. Mattson, In High Energy
Density Materials (Ed.: T. M. Klapçtke), Structure and Bonding 125,
Springer, Berlin, 2007, pp. 153–194.
[16] I. Hashiba, T. Tamura, H. Kousaka, U.S. Pat. 6878824 B2, 2005.
[17] A. Baliani, G. J. Bueno, M. L. Stewart, V. Yardley, R. Brun, M. P.
Barrett, I. H. Gilbert, J. Med. Chem. 2005, 48, 5570–5579.
[18] Y. Fan, G. Li, Z. Li, H. Hou, H. Mao, J. Mol. Struct. 2004, 693, 217–
224.
[1] a) H. Gao, J. M. Shreeve, Chem. Rev. 2011, 111, 7377–7436; b) R. P.
Singh, R. D. Verma, D. T. Meshri, J. M. Shreeve, Angew. Chem.
2006, 118, 3664–3682; Angew. Chem. Int. Ed. 2006, 45, 3584–3601;
c) Y.-H. Joo, J. M. Shreeve, Angew. Chem. 2009, 121, 572–575;
Angew. Chem. Int. Ed. 2009, 48, 564–567; d) Y.-H. Joo, J. M.
Shreeve, Angew. Chem. 2010, 122, 7478–7481; Angew. Chem. Int.
Ed. 2010, 49, 7320–7323.
[2] a) Y.-H. Joo, B. Twamley, J. M. Shreeve, Chem. Eur. J. 2009, 15,
9097–9104; b) Y.-H. Joo, B. Twamley, S. Garg, J. M. Shreeve,
Angew. Chem. 2008, 120, 6332–6335; Angew. Chem. Int. Ed. 2008,
47, 6236–6239; c) H. Xue, H. Gao, B. Twamley, J. M. Shreeve,
Chem. Mater. 2007, 19, 1731–1739; d) V. Thottempudi, J. M.
Shreeve, J. Am. Chem. Soc. 2011, 133, 19982–19992.
[19] J. C. Oxley, J. L. Smith, J. S. Moran, J. Energ. Mater. 2009, 27, 63–93.
[20] D. E. Chavez, M. A. Hiskey, J. Heterocycl. Chem. 1998, 35, 1329–
1332.
[3] a) Y.-H. Joo, J. M. Shreeve, J. Am. Chem. Soc. 2010, 132, 15081–
15090; b) R. Wang, H. Xu, Y. Guo, R. Sa, J. M. Shreeve, J. Am.
Received: September 12, 2013
Published online: October 21, 2013
Chem. Asian J. 2014, 9, 212 – 217
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