Article pubs.acs.org/jced
Solubility of Tetranitrodimerglycoluril (TNDGU) in Different Solvents at Temperatures between 293.15 K and 313.15 K Kejian Cui, Yumei Yang, Zihui Meng,* Guangrui Xu, Zhibin Xu,* and Min Xue School of Chemical & Environmental Engineering, Beijing Institute of Technology, Beijing 100081, China ABSTRACT: Tetranitrodimerglycoluril (TNDGU) is a newly developed insensitive energetic material. Its solubility in methanol, propanone, ethyl ethanoate, and ethanenitrile between 293.15 K and 313.15 K at atmospheric pressure was investigated by the gravimetric method. The order of the solubility of TNDGU is ethanenitrile > ethyl ethanoate ≈ propanone > methanol. The solubility of TNDGU increased with an increase of temperature. The enthalpy of dissolution in each solvent was also calculated according to a modified van’t Hoff equation; the values are 25.18 kJ·mol−1 for methanol, 41.26 kJ·mol−1 for propanone, 34.70 kJ·mol−1 for ethyl ethanoate, and 36.33 kJ·mol−1 for ethanenitrile, respectively.
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INTRODUCTION Tetranitrodimerglycoluril (TNDGU, C10H8N12O12, white powder, molecular weight 488.24, CAS Registry no. 141970416-7, Figure 1) is a novel explosive synthesized in 2013 by
In this study, the solubility of TNDGU in methanol, propanone, ethyl ethanoate, and ethanenitrile at temperatures ranging from 293.15 K to 313.15 K was measured using the gravimetric method.11,12 The enthalpy of dissolution was calculated from the experiment data using the modified van’t Hoff equation.
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Figure 1. Chemical structure of tetranitrodimerglycoluril.
Meng et al.1 It has an outstanding detonation performance with a high density (ρ, 1.93 g·cm−1) and velocity of detonation (VOD, 8305 m·s−1). Further characterization showed that its impact sensitivity is lower than that of 1,3,5-trinitroperhydro1,3,5-triazine (RDX), and its friction sensitivity is lower than that of 1,3,5,7-tetranitro-octahydro-1,3,5,7-tetrazocine (HMX).2 Such excellent performance indicated that it is a promising candidate for high energy density material. Generally, the purity of explosives is a crucial factor when energetic materials are tested, stored, and used.3−6 And the knowledge for the solubility of organics in different solvents is useful for their separation and purification process.7−10 Thus, it is important to obtain the solubility of TNDGU in different solvents in order to determine a suitable solvent and crystallization method. Currently, no data for the solubility of TNDGU have been reported. © 2014 American Chemical Society
EXPERIMENTAL SECTION
Chemicals. In the experiments, TNDGU (C10H8N12O12, CAS: 1419704-16-7) was prepared and purified according to the literature,2 its purity was higher than 0.994 in mass as determined by high-performance liquid chromatography (HPLC). Methanol, propanone, ethyl ethanoate, and ethanenitrile of analytical grade were purchased from local suppliers without further purification. Details of the chemical substances used in our study are shown in Table 1. Procedure. The solubility of TNDGU in methanol, propanone, ethyl ethanoate, and ethanenitrile were measured at temperatures of 293.15 K, 298.15 K, 303.15 K, 308.15 K, and 313.15 K, respectively. An excess amount of solid TNDGU was added into glass vials containing 10 mL of solvents. Then the vials were placed in a thermostatic bath at the selected temperatures which were measured by a precision thermometer with an uncertainty of ± 0.1 K. Magnetic stir bars were used to stir the mixtures continuously for 4 h, and then the solutions were stored at constant temperature for another 4 h. Thermodynamic equilibrium is established once the undissolved solute settled.13,14 For each vial, a portion of the supernatant was withdrawn by using a preheated syringe with a 0.22 μm membrane, and then the solution was transferred into Received: May 6, 2014 Accepted: July 26, 2014 Published: July 31, 2014 2620
dx.doi.org/10.1021/je500392g | J. Chem. Eng. Data 2014, 59, 2620−2622
Journal of Chemical & Engineering Data
Article
Table 1. Information of Chemicals Used in This Work chemical name tetranitrodimerglycoluril methanol
propanone
ethyl ethanoate
ethanenitrile
a
source
mass fraction purity
analysis method a
Table 2. Solubility of TNDGU as a Function of Temperature in Different Solvents under 0.1 MPaa
purification method
homemade
0.994
HPLC
recrystallization
Beijing Chemical Reagent Co., Ltd. Beijing Chemical Reagent Co., Ltd. Beijing Chemical Reagent Co., Ltd. Beijing Chemical Reagent Co., Ltd.
0.999
GCb
none
0.995
GC
none
0.997
GC
none
0.995
GC
none
solvent methanol
propanone
ethyl ethanoate
High performance liquid chromatography. bGas chromatography.
a double dish with a weight of m1. Then the double dish was quickly weighed using an electronic balance with the uncertainty of ± 0.01 mg to determine the total weight (m2). The solvent evaporation was carried out in air at room temperature and atmospheric pressure, and a piece of filter paper was put on the double dish to prevent dust contamination. After the evaporation of the solvent, the weight of the double dish containing the residue was weighed repeatedly until constant weights were obtained (m3). In these processes we insist that there were no evaporation losses of TNDGU, and TNDGU is the sole composition of the formed crystals. All of the experiments were repeated five times at each temperature. The molar solubility of the solute was determined, and the molar fraction (x) of the solute was determined according to the following equation: x=
(m3 − m1)/M1 (m3 − m1)/M1 + (m2 − m1)/M 2
ethanenitrile
100 δ
293.15 298.15 303.15 308.15 313.15 293.15 298.15 303.15 308.15 313.15 293.15 298.15 303.15 308.15 313.15 293.15 298.15 303.15 308.15 313.15
0.0910 0.1067 0.1261 0.1516 0.1741 1.119 1.423 2.057 2.594 3.197 1.293 1.552 1.997 2.470 3.198 1.505 1.818 2.480 3.096 3.790
0.0906 0.1074 0.1268 0.1493 0.1753 1.096 1.499 1.990 2.570 3.232 1.287 1.576 1.964 2.487 3.196 1.479 1.900 2.421 3.058 3.831
0.43 −0.65 −0.58 1.50 −0.65 1.98 −5.34 3.23 0.93 −1.07 0.47 −1.52 1.65 −0.69 0.06 1.58 −4.57 2.38 1.19 −1.24
Figure 2. Temperature dependence of ln (x) of TNDGU in different solvents: ■, methanol, ◆, propanone, ▲, ethyl ethanoate; ●, ethanenitrile.
RESULTS AND DISCUSSION Solubility. The solubilities of TNDGU in methanol, propanone, ethyl ethanoate, and ethanenitrile in the range of 293.15 K to 313.15 K are listed in Table 2. Figure 2 shows that the solubilities of TNDGU increased as an exponential rate in all of the solvents. And ln (x) shows the usual linear relationship with inverse absolute temperature. Therefore, the solubilities of TNDGU were correlated by the modified Apelblat equation.
where xcalc represents calculated solubility from eq 2. Table 3 lists the regression parameters of A, B, and C for eq 2 for all solvents tested. Enthalpy of Solution. The solubility can be predicted from van’t Hoff equation for an ideal solution, and for a nonideal solution, the enthalpy of solution can be calculated from the slope of the modified van’t Hoff equation. The enthalpy of solution (ΔsolH) for TNDGU was calculated by eq 4 and eq 5 according to the reference.7,15
(2)
where x is the molar fraction of solute, T is the absolute temperature, A, B, and C are the parameters of the exponential expression. The relative deviation (δ) which shows the relative differences between the experimental mole fractions and those calculated is defined in eq 3. (x − x calc) x
104 xcalc
(1)
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δ=
104 x
a Standard uncertainties u are u(T) = 0.1 K, ur(p) = 0.05, and related standard uncertainty ur(x) = 0.05 (0.95 level of confidence).
where M1 and M2 are the molecular weights of solute and solvent, respectively. The value of M1 is 488.24, and the values of M2 are 32.04 for methanol, 58.08 for propanone, 88.11 for ethyl ethanoate, and 41.05 for ethanenitrile, respectively. The uncertainty of the experiment measurements was about 5.0 % at the 95 % confidence level.
ln x = A + B /(T /K) + C ln(T /K)
T/K
Table 3. Parameters of eq 2 of TNDGU in Different Solvents
(3) 2621
solvent
A
B
C
R2
methanol propanone ethyl ethanoate ethanenitrile
−56.24 475.38 −574.67 21.79
−548.8 −26057.4 21990.9 −5078.2
8.185 −69.642 86.379 −2.339
0.9973 0.9881 0.9978 0.9890
dx.doi.org/10.1021/je500392g | J. Chem. Eng. Data 2014, 59, 2620−2622
Journal of Chemical & Engineering Data ln(x) =
ΔHsol ⎛ 1 1⎞ − ⎟+D ⎜ R ⎝ Tm T⎠ n
Tm =
Article
n
∑i = 1
() 1 Ti
(4) Morris, J. B. Solubility of RDX in Dense Carbon Dioxide at Temperatures between 303 and 353 K. J. Chem. Eng. Data 1998, 43, 269−273. (5) Ro, K. S.; Venugopal, A.; Adrian, D. D.; Constant, D.; Qaisi, K.; Valsaraj, K. T.; Thibodeaux, L. J.; Roy, D. Solubility of 2,4,6Trinitrotoluene (TNT) in Water. J. Chem. Eng. Data 1996, 41, 758− 761. (6) Xue, M.; Zhong, X.; Meng, Z. H.; Chen, Z.; Xu, M.; Jia, L.; Zhang, G. Determination of Ionic Residues in 3,4-Dinitrofurazan by Ionic Chromatography. Chin. J. Energ. Mater. 2012, 05, 650−652. (7) Bhesaniya, K.; Nandha, K.; Baluja, S. Thermodynamics of Fluconazole Solubility in Various Solvents at Different Temperatures. J. Chem. Eng. Data 2014, 59, 649−652. (8) Hu, Y.; Cao, Z.; Li, J.; Yang, W.; Kai, Y.; Zhi, W. Solubilities of 4Bromo-1,8-naphthalic Anhydride in Different Pure Solvents and Binary Solvent Mixtures with the Temperature Range from (278.15 to 333.15) K. J. Chem. Eng. Data 2013, 58, 2913−2918. (9) Liu, J.-Q.; Cao, X.-X.; Ji, B.; Zhao, B. Measurement and Correlation of Solubilities of Indole-2-carboxylic Acid in Ten Different Pure Solvents from (278.15 to 360.15) K. J. Chem. Eng. Data 2013, 58, 3309−3313. (10) Zhao, H.; Xu, H.; Yang, Z.; Li, R. Solubility of 3,4Dichloronitrobenzene in Methanol, Ethanol, and Liquid Mixtures (Methanol Plus Water, Ethanol Plus Water): Experimental Measurement and Thermodynamic Modeling. J. Chem. Eng. Data 2013, 58, 3061−3068. (11) Wang, L.; Xu, Z.; Wang, P.; Wang, L.; Lin, Z.; Meng, Z. Investigation of the Solubility of Octahydro-1,3,5,7-tetranitro-1,3,5,7tetrazocine and 1,3,5-Triacetyl-hexahydro-s-triazine. J. Chem. Eng. Data 2013, 58, 737−740. (12) Xu, H.; Zhang, B.; Yang, Z.; Yao, G.; Zhao, H. Solubility of Dichloronitrobenzene in Eight Organic Solvents from T= (278.15 to 303.15) K: Measurement and Thermodynamic Modeling. J. Chem. Eng. Data 2014, 59, 1281−1287. (13) 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, 51, 448−450. (14) Prak, D. J. L.; O’Sullivan, D. W. Solubility of 4-Nitrotoluene, 2,6-Dinitrotoluene, 2,3-Dinitrotoluene, and 1,3,5-Trinitrobenzene in Pure Water and Seawater. J. Chem. Eng. Data 2007, 52, 2446−2450. (15) Li, Q.; Lu, F.; Tian, Y.; Feng, S.; Shen, Y.; Wang, B. Solubility of Veratric Acid in Eight Monosolvents and Ethanol + 1-Butanol at Various Temperatures. J. Chem. Eng. Data 2013, 58, 1020−1028.
(4)
n=5 (5)
where ΔsolH is the enthalpy of solution, R is the gas constant, T is absolute temperature, and D is a equation parameter. Tm is the mean harmonic temperature, n is the number of experimental temperatures. The values of enthalpy of solution (ΔsolH) are shown in Table 4. Table 4. Values of Enthalpy of Solution of TNDGU in Different Solventsa solvent
methanol
propanone
ethyl ethanoate
ethanenitrile
25.18
41.26
34.70
36.33
−1
ΔHsol/kJ·mol
Combined expanded uncertainties U are Uc(ΔH) = 2 kJ·mol−1 (0.95 level of confidence).
a
From Table 2 and Figure 2, it can be seen that TNDGU has the highest solubility in ethanenitrile, higher than that of in propanone and ethyl ethanoate, and much higher than that of in methanol. The solubility in propanone varies much more obviously to temperature than in other solvents over the selected temperature range.
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CONCLUSIONS The solubility of TNDGU in methanol, propanone, ethyl ethanoate, and ethanenitrile under temperatures ranging from 293.15 K to 313.15 K was measured by using the gravimetric method in this work. In terms of the temperature effect, the solubility of TNDGU is increased with the increase of temperature in all solvents studied. Experimental results show the solubility order is ethanenitrile > ethyl ethanoate ≈ propanone > methanol. The enthalpy of solution was calculated to be 25.18 kJ·mol−1 for methanol, 41.26 KJ·mol−1 for propanone, 34.70 KJ·mol−1 for ethyl ethanoate, and 36.32 KJ· mol−1 for ethanenitrile, respectively, by the regression analysis of the experimental solubility data.
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AUTHOR INFORMATION
Corresponding Authors
*E-mail:
[email protected] (Z.-h. M.). *E-mail:
[email protected] (Z.-b. X.); Tel./fax: 86-10-68913065. Notes
The authors declare no competing financial interest.
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REFERENCES
(1) Meng, Z. H.; Xu, G. R.; Xu, Z. B.; Wang, P.; Cui, K. J. Process for preparation of tetranitroglycoluril dimer from nitration of glycoluril dimer. China Patent CN102875557A, 2013. (2) Cui, K. J.; Xu, G. R.; Xu, Z. B.; Wang, P.; Meng, Z. H.; Li, J. R.; Wang, B. Z.; Ge, Z. X.; Qin, G. M. Synthesis and Characterization of a Thermally and Hydrolytically Stable Energetic Material Based on NNitrourea. Propellants Explos. Pyrotech. 2014 (DOI:10.1002/ prep.201300100, in press). (3) Foltz, M. F.; Ornellas, D. L.; Pagoria, P. F.; Mitchell, A. R. Recrystallization and Solubility of 1,3,5-Triamino-2,4,6-trinitrobenzene in Dimethyl Sulfoxide. J. Mater. Sci. 1996, 31, 1893−1901. 2622
dx.doi.org/10.1021/je500392g | J. Chem. Eng. Data 2014, 59, 2620−2622
