Solubility of 3,7-Dinitro-1,3,5,7-tetraazabicyclo [3.3.1] Nonane in Ethanenitrile, Methanol, 1,1-Dichloroethane, Dimethyl Sulfoxide, Acetone, and Mixed Solvents

Article abstract of DOI:10.1021/acs.jced.5b00033

The solubility of 3,7-dinitro-1,3,5,7-tetraazabicyclo [3.3.1] nonane (DPT) was measured in ethanenitrile, methanol, 1,1-dichloroethane, dimethyl sulfoxide (DMSO), acetone, ethyl acetate, ethyl acetate and methanol mixture, and acetonitrile and water mixture from 288.15 K to 308.15 K. In this paper, the determination method of DPT was first established by high-performance liquid chromatography (HPLC) with optimized chromatographic conditions. The solubility of DPT in all solvents was measured upon this chromatographic method. Experimental results show that the order of solubility can be represented as DMSO > acetonitrile > ethyl acetate > ethyl acetate/methanol (9:1, v/v) > ethyl acetate/methanol (7:3, v/v) > acetone > acetonitrile/water (9:1, v/v) > ethyl acetate/methanol (5:5, v/v) > acetonitrile/water (7:3, v/v) > 1,1 - dichloroethane > methanol. Moreover, its solubility increased with raising the temperature. The thermodynamic properties of DPT, such as solution enthalpy, have also been calculated.

Full text of DOI:10.1021/acs.jced.5b00033

Article
pubs.acs.org/jced
Solubility of 3,7-Dinitro-1,3,5,7-tetraazabicyclo [3.3.1] Nonane in
Ethanenitrile, Methanol, 1,1-Dichloroethane, Dimethyl Sulfoxide,
Acetone, and Mixed Solvents
†
†
†
†
,†
‡
Min Xue, Siyu Wu, Wenjin Liu, Qiao Zhu, Zihui Meng,* and Zhihui Lin
†School of Chemical Engineering & Environment, Beijing Institute of Technology, Beijing, 100081, China
‡Chinese Academy of Arsenal, Beijing, 100086, China
ABSTRACT: The solubility of 3,7-dinitro-1,3,5,7-tetraazabicyclo
[
3.3.1] nonane (DPT) was measured in ethanenitrile, methanol, 1,1-
dichloroethane, dimethyl sulfoxide (DMSO), acetone, ethyl acetate,
ethyl acetate and methanol mixture, and acetonitrile and water mixture
from 288.15 K to 308.15 K. In this paper, the determination method of
DPT was first established by high-performance liquid chromatography
(
HPLC) with optimized chromatographic conditions. The solubility of
DPT in all solvents was measured upon this chromatographic method.
Experimental results show that the order of solubility can be
represented as DMSO > acetonitrile > ethyl acetate > ethyl acetate/
methanol (9:1, v/v) > ethyl acetate/methanol (7:3, v/v) > acetone >
acetonitrile/water (9:1, v/v) > ethyl acetate/methanol (5:5, v/v) >
acetonitrile/water (7:3, v/v) > 1,1 - dichloroethane > methanol.
Moreover, its solubility increased with raising the temperature. The thermodynamic properties of DPT, such as solution
enthalpy, have also been calculated.
INTRODUCTION
solvents is critical to the recrystallization solvent and procedure
optimization.
Considering DPT is a sensitive explosive compound, the
■
12
3
,7-Dinitro-1,3,5,7-tetraazabicyclo [3.3.1] nonane (DPT) is
well-known as the key intermediate of octahydro-1,3,5,7-
tetranitro-1,3,5,7-tetrazocine (HMX) synthesized from hexam-
traditional gravimetric analysis for the determination of the
13
1
solubility is inconvenient due to the amount used. In this
research, we used high-performance liquid chromatography
ethylenetetramine (HA). HMX is one of the most powerful
explosives and can be synthesized by nitrify DPT with nitric
acid and nitrogen pentoxide (Figure 1). Such a process was
confirmed as the most efficient and economic method with
lower cost, high purity, easy control, and environmentally
(
HPLC) to determine the concentration of DPT in solution.
Therefore, a relatively far less amount of solid DPT was needed
to obtain the oversaturated solution in less volume solvents.
The solubility of DPT was decided in acetonitrile, methanol,
acetone, DMSO, ethylene dichloride, ethyl acetate, ethyl acetate
and methanol mixture, and acetonitrile and water mixture in the
temperature range from 288.15 K to 308.15 K. The
thermodynamic properties of DPT were also determined
based on its solubility.
2
,3
friendly for the production of HMX.
DPT is an unstable explosive, which has a lower impact
sensitivity than TNT. Pure DPT compound is white diamond
crystal of two kinds of form, whose melting points are 495.15 K
4
to 496.15 K and 477.15 K to 478.15 K. Its density is 1.63 g·
−3
3
cm . Wright first synthesized DPT by sulfuric acid and
1
methenamine dinitrate with 31 % yield in 1949. After that,
different synthetic schemes were reported to improve the
procedure and the yield. Along with the improvement of
EXPERIMENTAL SECTION
5
,6
■
Chemicals and Analytical Method. The DPT (3,7-
dinitro-1,3,5,7-tetraazabicyclo [3.3.1] nonane, C H N O ,
DPT synthesis, its purification also attracted considerable
4
5
10
6
2
concerns. It is reported that high-purity DPT can recrystallized
CAS: 101-25-7) with a purity of 99.98 % was provided by
Xi’an Modern Chemistry Research Institute, China. The
acetonitrile, methanol, 1,1-dichloroethane, DMSO, acetone,
and ethyl acetate were purchased from local suppliers without
further purification (Table 1). Deionized water (18.25 MΩ·
from acetone, ethyl acetate, nitromethane, 4-dioxane, and acetic
7
anhydride.
In general, the explosive properties of high energy compound
8
,9
are significantly influenced by its purity. In addition, its
crystallization properties such as crystal shape, particle size
distribution, crystal morphology, and polycrystalline, also
1
0,11
contributes to its combustion rate and ballistic propulsion.
Received: November 19, 2014
Accepted: May 4, 2015
Therefore, in order to get high purity product in reasonable
crystal size and shape, the solubility of DPT in different
Published: May 13, 2015
©
2015 American Chemical Society
1683
DOI: 10.1021/acs.jced.5b00033
J. Chem. Eng. Data 2015, 60, 1683−1687

Journal of Chemical & Engineering Data
Article
Figure 1. Synthetic route of HMX.
−
1
cm ) was obtained from a Millipore Mili-Q Plus water system.
The chromatographic conditions were optimized, and a
symmetrical sharp peak was obtained; the mass fraction purity
is 0.9998 when methanol/water (10:90, v/v) was used as
All solutions were filtered through 0.45 μm membranes
China) before usage.
(
−1
mobile phase, and the flow rate was 1.0 mL·min (Figure 2).
Table 1. Information of Chemicals Used in This Work
mass
fraction
purity
analysis
method
purification
method
chemical name
DPT
source
a
Xi’an Modern
Chemistry
Research
Institute, China
99.98 %
HPLC
none
b
acetonitrile
methanol
J.T. Baker Co., Ltd. 99.99 %
J.T. Baker Co., Ltd. 99.99 %
J.T. Baker Co., Ltd. 99.99 %
GC
none
none
none
GC
GC
1,1-
dichloroethane
DMSO
J.T. Baker Co., Ltd. 99.99 %
J.T. Baker Co., Ltd. 99.99 %
J.T. Baker Co., Ltd. 99.99 %
GC
GC
GC
none
none
none
acetone
ethyl acetate
a
b
High-performance liquid chromatography. Gas chromatography.
Figure 2. HPLC chromatogram of DPT.
The purity and content analysis of DPT was performed on a
Shimadzu HPLC system (Japan), which consists of two LC-
0AT pumps, a SPD-20 UV detector and a SIL-10A auto
sampler. A C18 column (250 mm × 4.6 mm, 5 μm, Agela) and
a UV detector at 254 nm length was adopted. Aliquots of 10 μL
of the reconstituted samples were injected for HPLC analysis.
The DPT standard solution was prepared from 0.003 mg·
2
−1
−1
mL to 3.0 mg·mL in acetonitrile. The calibration curve of
chromatogram peak area to concentration of DPT by HPLC
was established (Figure 3). The limit of detection is 0.003 mg·
−
1
mL .
EXPERIMENTAL PROCEDURE
■
First, put an extra amount of DPT solid into a glass vial with 5
mL of acetonitrile, methanol, 1,1-dichloroethane, DMSO,
acetone, mixtures of ethyl acetate and methanol, and mixtures
of acetonitrile and water respectively to get the supersaturated
solutions. Then, incubate the vial in temperature thermostatic
reaction bath with magnetic stirring water bath at 288.15 K,
2
93.15 K, 298.15 K, 303.15 K, and 308.15 K, respectively. The
temperature was determined using a pure solvent bottle with a
thermometer inside. The temperature fluctuation of the
thermostatic reaction bath was controlled below ± 0.5 K, and
the temperature uncertainty is ± 0.1 K. Withdraw aliquots of 1
mL supernatant of each vial by a syringe with a 0.22 μm
membrane after the dissolution equilibrium of DPT with
1
4,15
another 12 h standing at the corresponding temperature.
Transfer the solution to a dried weighted double dish, and
weigh the dish quickly to determine the mass of the solution
Figure 3. Linear relationship between the chromatogram peak area
(
m ) with the uncertainty of ± 0.1 mg. After the solution is
0
(
Y) and the concentration (X) of DPT in acetonitrile.
completely dried under nitrogen, dissolve the residue in
acetonitrile, and exactly dilute to 10 mL. Take 10 μL of the
reconstituted samples for HPLC analysis. All of the experi-
ments were carried out 5 times simultaneously and analyzed by
HPLC.
6
5
The linear fitting equation is Y = 8.3·10 X + 2.5·10 over the
concentration range of 0.003 mg·mL− to 3.0 mg·mL .
Solubility. The solubility of DPT is expressed by mole
fraction of the solute in the solution. While the DPT
concentration in solubility experiments were estimated by the
HPLC method according to the calibration curve, the mass of
the solute in the sample solution was calculated by product of
1
−1
RESULT AND DISCUSSION
High-Performance Liquid Chromatography (HPLC)
Detection. The purity of DPT was determined by HPLC.
■
1
684
DOI: 10.1021/acs.jced.5b00033
J. Chem. Eng. Data 2015, 60, 1683−1687

Journal of Chemical & Engineering Data
Article
Table 2. Solubility of DPT as a Function of Temperature in Different Solvents under 0.1 MPa
solvent
T/K
x
xcalc
100δ
7
7
7
7
7
9
9
9
9
9
8
8
8
7
7
7
6
6
6
6
9
9
9
8
8
8
8
7
−7
−7
−7
−7
−7
−9
−9
−9
−9
−9
−8
−8
−8
−8
−7
−7
−6
−6
−6
−6
−9
−9
−9
−8
−8
−8
−8
−7
−7
−7
−8
−8
−8
−8
−8
−7
−7
−7
−7
−7
−7
−7
−7
−7
−7
−8
−7
−7
−7
−7
−8
−8
−8
−8
−7
acetonitrile
methanol
acetone
288.15
1.54176·10−
1.78147·10−
1.99383·10
2.25782·10−
1.55108·10
1.75950·10
1.98741·10
2.24005·10
2.50868·10
5.48825·10
5.89257·10
6.31146·10
6.75198·10
7.19718·10
7.11535·10
7.97073·10
8.89464·10
9.90658·10
1.09701·10
9.28945·10
1.05013·10
1.18220·10
1.32812·10
1.48277·10
7.09331·10
8.47768·10
9.93588·10
1.16125·10
1.34592·10
6.52624·10
9.37267·10
1.12926·10
1.28126·10
1.42326·10
1.70292·10
2.15498·10
2.57764·10
2.92205·10
3.15705·10
1.02634·10
1.17265·10
1.31926·10
1.54268·10
1.84233·10
1.05265·10
1.17269·10
1.29261·10
1.51268·10
1.82326·10
9.92526·10
1.10726·10
1.20926·10
1.43126·10
1.73326·10
2.84408·10
4.65752·10
6.90759·10
9.51575·10
1.17408·10
−0.604519891
1.233424867
0.3217413
293.15
298.15
303.15
308.15
−
0.78705409
−
2.49821·10
−0.418824629
−0.105455565
−1.639492793
0.783648856
−1.270460111
0.528200092
−0.735995228
0.138898981
0.116072584
2.409672406
−1.979894997
−0.159026313
−0.288116712
−0.289613711
2.314143304
−1.536332083
−18.978783344
19.924440234
−0.609550243
5.480214213
−10.26622687
1.675063348
−0.436082937
−0.006509495
0.329681559
−0.809611225
0.954765745
−0.131937878
−0.77679513
−0.039796138
0.832259367
−0.263202867
−1.070414909
−0.519231925
0.405665452
0.067695099
−2.681647775
−2.558796733
0.385876203
−0.099337088
0.627002014
0.206966209
−0.209063018
−0.055816445
0.473744264
−0.51850375
0.442843353
−0.754109069
−2.821182748
−0.40996652
0.258795033
288.15
5.48247·10−
−
293.15
298.15
303.15
308.15
5.79752·10
6.36131·10−
6.66727·10−
−
7.23540·10
288.15
7.06336·10−
7.98181·10−
8.90498·10−
1.01512·10−
293.15
298.15
303.15
308.15
−
1.07572·10
DMSO
288.15
9.27470·10−
1.04711·10−
293.15
298.15
303.15
308.15
−
1.17879·10
1.35958·10−
−
1.46033·10
1,1-dichloroethane
288.15
7.04587·10−
8.45871·10−
293.15
298.15
303.15
308.15
−
9.87569·10
1.22858·10−
−
1.32061·10
acetonitrile/water (9:1, v/v)
acetonitrile/water (7:3, v/v)
ethyl acetate
288.15
6.63718·10−
9.33191·10−
293.15
298.15
303.15
308.15
−
1.12919·10
1.2855·10−
7
−
7
8
8
8
8
8
7
7
7
7
7
7
7
7
1.41183·10
288.15
1.72144·10−
2.14717·10−
293.15
298.15
303.15
308.15
−
2.55069·10
2.92089·10−
−
3.18355·10
288.15
1.02331·10−
1.16018·10−
293.15
298.15
303.15
308.15
−
1.31245·10
1.54888·10−
−
1.84357·10
ethyl acetate/methanol(9:1, v/v)
ethyl acetate/methanol(7:3, v/v)
ethyl acetate/methanol(5:5, v/v)
288.15
1.02511·10−
1.14334·10−
293.15
298.15
303.15
308.15
−
1.29761·10
1.5111·10−
7
−
7
8
7
7
7
7
8
8
8
1.83476·10
288.15
9.94584·10−
1.10495·10−
293.15
298.15
303.15
308.15
−
1.20859·10
1.43807·10−
−
1.72432·10
288.15
2.85673·10−
4.62264·10−
293.15
298.15
303.15
308.15
−
6.71797·10
9.4769·10
1.17712·10−
−8
7
a
Standard uncertainties u are u(T) = 0.1 K, u (p) = 0.05, and u (x) = 0.04.
r
r
m /M
1
the concentration (c) and the volume of diluted (V). Thus, the
mole fraction of the solute can be easily calculated according to
the following equation.
1
x =
m /M + (m − m )/M
(1)
1
1
0
1
2
1
685
DOI: 10.1021/acs.jced.5b00033
J. Chem. Eng. Data 2015, 60, 1683−1687

Journal of Chemical & Engineering Data
Article
where x is the mole fraction; m is the mass of the solution; m1
0
is the mass of the solute (DPT) as the product of the
concentration (c) and the volume of diluted (V); M is the
1
molecular weight of solute; M is the molecular weight of
2
solvent.
According to the thermodynamic principle of solid−liquid
equilibrium, there is a relationship between the solubility (x)
16
and the temperature (T).
⎛
⎝
⎞
⎠
ΔHtp
R
ΔC ⎛ Ttp
Ttp
⎞
1
Ttp
1
T
p
ln γx = −
⎜
⎜
−
⎟ −
⎜ln
− T + 1⎟
⎟
R ⎝
T
⎠
ΔV
RT
−
(P − Pw)
(
2)
Here, γ is activity factor of the solute; x is the mole fraction; T
is the absolute temperature, K; Ttp is the triple point
temperature of the solute, K; ΔH is the enthalpy of fusion
tp
−1
at the triple point temperature, J·mol ; R is molar gas constant,
−
1
J·(mol·K) ; ΔC is the heat capacity difference; ΔV is the
p
volume difference; P is the vapor pressure at the point
Figure 4. Temperature dependence of mole fraction of DPT in several
solvents: blue ◆, acetonitrile; red ■, methanol; green ▲, acetone;
temperature, Pa; P is the vapor pressure at the time of solid−
w
liquid equilibrium, Pa.
purple ×, DMSO; blue ∗, 1,1-dichloroethane; orange ●, acetonitrile/
Considering the heat capacity difference and volume
difference is too low to count, the equation can be simplified
as follows:
water (9:1, v/v); blue +, acetonitrile/water (7:3, v/v); orange −, ethyl
acetate; green −, ethyl acetate/methanol (9:1, v/v); purple ◆, ethyl
acetate/methanol (7:3, v/v); blue ■, ethyl acetate/methanol (5:5, v/
v).
⎛
⎜
⎞
⎟
ΔHm
R ⎝T
1
1
T ⎠
ln γx = −
−
m
(3)
Here Tm is the melting point temperature of the solute, K;
ΔH is the enthalpy of fusion at this temperature, J/mol;
m
The activity factor can also be expressed as following,
ln γ = a + b
(4)
T
While input eq 4 to eq 3,
⎛
ln x = ⎜
⎝
⎞
ΔHm
RTm
⎛ΔH
⎞ 1
− b⎟
⎠T
m
− a⎟ − ⎜
⎝ R
⎠
(5)
Considering ((ΔH /RT ) − a) and ((ΔH /R) − b) are all
m
m
m
constants, the mole fraction can finally be expressed as
following,
B
T(K)
ln x = A +
(6)
Here A and B are parameters of the exponential expression.
So, the solubility can also be calculated with eq 6, while the
linearity between ln x and T was established.
Figure 5. Temperature dependence of ln x of DPT in several solvents:
blue ◆, acetonitrile; pink ■, methanol; black ▲, acetone; ■ with ×,
DMSO; ■ with +, 1,1-dichloroethane; orange ●, acetonitrile/water
The relative deviation (δ) is defined in eq 7.
(
9:1, v/v); gray +, acetonitrile/water (7:3, v/v); orange −, ethyl
acetate; green −, ethyl acetate/methanol (9:1, v/v); purple
◆
, ethyl
calc
x − x
acetate/methanol (7:3, v/v); blue ■, ethyl acetate/methanol (5:5, v/
δ =
x
(7)
v).
Here, xcalc is the calculated solubility from eq 6.
The solubilities of DPT in acetonitrile, methanol, 1,1-
dichloroethane, DMSO, acetone, and mixed solvents in the
range of 288.15 K to 308.15 K are listed in Table 2. The linear
relationship between mole fraction and inverse absolute
temperature was obtained (Figure 4).
The solubilities of DPT in all solvents increased at an
exponential rate with raising the temperature in all of the
experiments. Then the linear relationship between ln x and
inverse absolute temperature was also illustrated in Figure 5.
Therefore, the regression parameters of A and B involved in
eq 6 can be obtained, and the exact data are listed in Table 3.
Moreover, the calculated mole fractions and the relative
deviations are recorded in Table 2.
Enthalpy of Solution. To insight into the DPT dissolve
process in each solvents, we calculated the enthalpy of solution
(Δ H) by van’t Hoff equation.
sol
1
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DOI: 10.1021/acs.jced.5b00033
J. Chem. Eng. Data 2015, 60, 1683−1687

Journal of Chemical & Engineering Data
Article
Table 3. Parameters of eqs 6 and 8 for DPT in Different Solvents
solvent
A
B
R2
Δ H/(KJ·mol−1)
sol
acetonitrile
methanol
acetone
−8.2636
−14.8400
−9.7814
−6.6770
−8.9205
−4.8601
−8.3195
−7.2237
−7.7805
−7.7310
−4.6425
−2136.9
−1204.8
−1924.1
−2078.3
−2835.0
−3340.9
−2743.7
−2560.4
−2396.1
−2428.1
−6322.2
1
1
1
1
−17.7662
−10.0167
−81.3259
−17.2790
−23.1503
−28.5326
−22.8723
−20.8435
−19.9432
−20.4324
−80.9874
DMSO
1,1-dichloroethane
0.9997
0.9902
0.9977
0.9902
0.9947
0.9988
0.9928
acetonitrile/water (9:1, v/v)
acetonitrile/water (7:3, v/v)
ethyl acetate
ethyl acetate/methanol(9:1, v/v)
ethyl acetate/methanol(7:3, v/v)
ethyl acetate/methanol(5:5, v/v)
−
Δ H
−Δ S
(10) Ahn, J. H.; Kim, J. K.; Kim, H. S.; Kim, E. J.; Koo, K.-K.
Solubility of 1,1-Diamino-2,2-dinitroethylene in N,N-Dimethylforma-
mide, Dimethyl Sulfoxide, and N-Methyl-2-pyrrolidone. J. Chem. Eng.
Data 2009, 3259−3260.
sol
sol
ln x =
+
R(T/K)
R
(8)
Here, Δ H is the enthalpy of solution; Δ S is the entropy of
solution, R is the gas constant; T is the absolute temperature.
All of the data are shown in Table 3, and R is the correlation
coefficient for eq 8.
sol
sol
(
11) Yu, N.; Wang, D. Review on the technology of synthesis of
HMX. Chem. Intermed. 2011, 03, 006.
12) Mullin, J. W. Crystallization, 4th ed.; Butterworth-Heinemann:
Boston, 2001; pp 105−106.
13) Belny, D. H. M.; Mullin, J. W. Solubilities of Higher Normal
Alkanes in m-Xylene. J. Chem. Eng. Data 2006, 9−10.
14) Prak, D. J. L.; O’Sullivan, D. W. Solubility of 2,4-dinitrotoluene
and 2,4,6-trinitrotoluene in seawater. J. Chem. Eng. Data 2006, 448−
50.
15) Prak, D. J. L.; O’Sullivan, D. W. Solubility of 4-nitrotoluene, 2,6-
2
(
(
CONCLUSIONS
■
(
The solubility of DPT in several solvents under the
temperature ranging from 288.15 K to 308.15 K was measured
by the HPLC method. Besides the commonly used solvents, it
was also studied in acetonitrile−water mixture and ethyl
acetate-methanol mixture in different ratio. The solubility of
DPT increased as exponential rate as temperature increased in
all of the tested solvents. Moreover, the enthalpy of solution
was calculated by van’t Hoff equation.
4
(
dinitrotoluene, 2,3-dinitrotoluene, and 1,3,5-trinitrobenzene in pure
water and seawater. J. Chem. Eng. Data 2007, 2446−2450.
(16) Han, D. Physical Chemistry; Higher Education Press: Beijing,
2003; pp 260−262.
AUTHOR INFORMATION
■
Corresponding Author
E-mail: m_zihui@yahoo.com.
*
Notes
The authors declare no competing financial interest.
REFERENCES
■
(
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DOI: 10.1021/acs.jced.5b00033
J. Chem. Eng. Data 2015, 60, 1683−1687