Journal of Molecular Modeling (2018) 24: 50 https://doi.org/10.1007/s00894-018-3588-9
ORIGINAL PAPER
Estimating the densities of benzene-derived explosives using atomic volumes
Vikas D. Ghule1 & Ayushi Nirwan1 & Alka Devi1
Received: 7 November 2017 /Accepted: 8 January 2018 /Published online: 9 February 2018 # Springer-Verlag GmbH Germany, part of Springer Nature 2018
Abstract The application of average atomic volumes to predict the crystal densities of benzene-derived energetic compounds of general formula CaHbNcOd is presented, along with the reliability of this method. The densities of 119 neutral nitrobenzenes, energetic salts, and cocrystals with diverse compositions were estimated and compared with experimental data. Of the 74 nitrobenzenes for which direct comparisons could be made, the % error in the estimated density was within 0–3% for 54 compounds, 3–5% for 12 compounds, and 5–8% for the remaining 8 compounds. Among 45 energetic salts and cocrystals, the % error in the estimated density was within 0–3% for 25 compounds, 3–5% for 13 compounds, and 5–7.4% for 7 compounds. The absolute error surpassed 0.05 g/cm3 for 27 of the 119 compounds (22%). The largest errors occurred for compounds containing fused rings and for compounds with three –NH2 or –OH groups. Overall, the present approach for estimating the densities of benzene- derived explosives with different functional groups was found to be reliable.
Keywords Density . Atomic volume . Explosive . Group additivity method . Energetic salts
Introduction providing that the density and heat of formation values fed into the formula are reliable. The synthesis or hypothetical design of new explosive com- The purpose of the work reported in the present paper was to pounds requires the evaluation of various molecular and energet- develop a simple and straightforward correlation for predicting ic properties in order to select promising molecules. Superior the densities of benzene-derived explosives. Various methods performance is always the decisive factor in high-explosive ap- of estimating the densities of different classes of explosives plications, and a high density is crucial to maximizing the deto- based on group additivity and quantum chemistry software nation performance of an explosive. The relationship between have been reported. Among these, the group additivity ap- density and explosive power is highlighted by an empirical for- proach is one of the most straightforward, as it involves simply mula devised by Kamlet and Jacobs [1] to estimate detonation summing the volumes of the atoms or groups in the molecule parameters. Indeed, this formula indicates that the detonation [2–13]. While group additivity or volume-based approaches performance is much more strongly influenced by the density have the benefits of being inexpensive and easy to use, they of the explosive than its heat of formation. It is known that the are known to give the same densities for isomers and poly- formula can be used to evaluate the detonation properties of morphs. On the other hand, methods based on quantum chem- CHNOexplosivestowithintheexperimentalmeasurementerror, istry software require computationally expensive calculations [14–24]. All of these methods can give reasonably predictive modelsforenergeticcompoundsandtaketheconformationand Electronic supplementary material The online version of this article interactions into account in the crystal packing efficiency. (https://doi.org/10.1007/s00894-018-3588-9) contains supplementary Benzene-derived explosives are prominent in the literature on material, which is available to authorized users. energetic materials due to their high densities, low sensitivities, and high thermal stabilities. Inspired by the work of Hofmann * Vikas D. Ghule [email protected] [11], in the present study, we used the average atomic volume to predict the densities of explosives containing one or more ben- 1 Department of Chemistry, National Institute of Technology zene rings, and included a correction for the amino groups in the Kurukshetra, Kurukshetra, Haryana 136119, India compound to further improve the density estimation. 50 Page 2 of 18 J Mol Model (2018) 24: 50
Results and discussion To demonstrate the reliability of Eqs. 2 and 3, the densities of 119 benzene-derived explosives were predicted and com- In recent years, several methods for predicting crystal density pared with corresponding experimental data. The predicted have been reported that divide explosives into different classes densities and percentage errors relative to the experimental and apply various descriptors. The success of a density pre- data are given in Tables 2 and 3. Table 2 shows that the den- diction approach depends on its ability to estimate inter- and sities predicted for nitrobenzenes (entries 1–6) had % errors of intramolecular interactions, steric hindrance, conjugation, and less than 2.18% (0.04 g/cm3). For the OH-substituted nitro- ring systems, as well as to account for the effects of benzenes (entries 7–12, 22), the maximum % error was esti- 3 explosophores such as NO2,NH2,OH,N3,ONO2,and mated to be 3.65% (0.06 g/cm ), while the % error for 2,4,6- NHNO2 groups. The crystal density of a neutral or ionic com- trinitrobenzene-1,3,5-triol (entry 27) was 4.41%, which may pound can be estimated from its molecular volume (VM)and be attributed to the complexity of the interactions involving its molecular mass (MW) via three OH groups. Nitrobenzenes containing a CH3 moiety (entries 13–16) or an NH2 group (entries 17–20) showed max- MW imum % errors of 3.26% (0.05 g/cm3) and 3.33% (0.06 g/ Density ðÞ¼ρ : ð1Þ 3 V M cm ), respectively. The predicted density of TATB (entry 21) showed a maximum deviation of 7.82%, which may be due to It has been reported that the volumes of the atoms compris- its complex inter- and intramolecular H-bonding. Entries 24– ing the explosive compound can be used to calculate its den- 26 and 28–34 contain various bulky groups on the benzene sity. Indeed, Hofmann [11] reported that the average atomic ring, and the presence of an ONO2, CN, NHNH2, NHNO2, volumes of various elements as well as thermal expansion can N3, or guanidine group resulted in a maximum error of 6.3%. be used to predict the density of an explosive as follows: The compounds with two benzene rings in their structures (entries 35–45, 73, and 74) showed a maximum error of 5.08%. Nitrobenzotriazoles (entries 49–72) with a CH , ðÞ¼ρ MWexplosive  : ; ð Þ 3 Density 0 00164 2 NH ,orOCH group showed maximum deviations of up to ðÞaVC þ bVH þ cVN þ dVO 2 3 6%. The densities calculated in the present work were com- pared with previous results reported by Rice et al. [17]and where a, b, c,andd are the numbers of carbon, hydrogen, Politzer et al. [21], which were computed using an electrostat- nitrogen, and oxygen atoms in a molecule of the explosive, ic potential approach. The predicted values are in good agree- respectively. V , V , V ,andV are the volumes of the cor- C H N O ment with the experimental and reported results (see Table S1 responding atoms, which are summarized in Table 1. Density in the BElectronic supplementary material,^ ESM). estimation for compounds with strong H-bonding or with Considering the complexities of the inter- and intramolecular strong van der Waals or electrostatic interactions is more com- interactions involved in density prediction, the present ap- plex and challenging. While various corrections to group ad- proach appears to be reliable for neutral benzene-derived ditivity methods have been suggested to account for H- explosives. bonding between amino and oxygen-containing groups, the The predicted densities for salts and cocrystals are summa- resulting methods underestimate the density [8, 9, 13]. We rized in Table 3. TNT, picric acid, and trinitrobenzene have have observed that the presence of two or more NH2 or + been widely used in the preparation of cocrystals owing to NH groups in the molecule of an explosive compound in- 3 their excellent thermal stabilities and reasonable energetic creases its density. Hence, along with the atomic volumes, the + properties. Therefore, most of the salts and cocrystals studied contributions from NH and/or NH groups should also be 2 3 in this work contained these compounds. For the picric acid accounted for, leading to the following optimized expression: salts and cocrystals (entries 75, 79–81, 84–95, 101–103, and MW 105 in Table 3), the % error was less than 5% except for the ðÞ¼ρ explosive  : : ð Þ ′ Density ðÞaV þ bV þ cV þ dV 0 00175 3 1,1 -methylenebis(imidazolium) (entry 79) and 1,2,4- C H N O triazolium (entry 89) salts. Further, among the TNT- containing cocrystals (entries 104, 106, 109, and 111–119 in Table 3), the anthracene and phenylenediamine cocrystals Table 1 The atomic showed % errors of 7.09 and 6.8%, respectively. All other Element Atomic volume (nm3) volumes of C, H, N, and salts and cocrystals presented errors of less than 5% in their Oat298K[11] C 0.01387 estimated densities. As can be seen in Table S2 of the ESM, H 0.00508 the densities predicted using Eq. 3 for compounds containing + N0.0118 two or more NH2 or NH3 groups in their molecular structures O0.01139 displayed excellent agreement with the corresponding exper- imental values, in contrast to the densities computed via Eq. 2. JMolModel(2018)24:50 Page 3 of 18 50
Table 2 Predicted densities for neutral benzene-derived explosives Expt. Calculated MW Compd. Name Structure MF Density Density (g/mol) (g/cm3) (g/cm3)
NO 2
NO 2 1.56 1 1,2-Dinitrobenzene C6H4N2O4 168.10 1.60 (-2.18) [2,3]
NO 2 1.57 2 1,3-Dinitrobenzene C6H4N2O4 168.10 1.60 (-1.56) [2,3]
NO 2
NO 2
1.62 3 1,4-Dinitrobenzene C6H4N2O4 168.10 1.60 (1.56) [2,3]
NO 2
NO 2 1.69 4 1,3,5-Trinitrobenzene C6H3N3O6 213.10 1.73 (-2.31) [2,3]
O2N NO 2
NO 2
NO 2 1.73 5 1,2,4-Trinitrobenzene C6H3N3O6 213.10 1.73 (0.0) [2,3]
NO 2
NO 2
O2N NO 2 1.98 6 Hexanitrobenzene C6N6O12 348.10 1.96 (1.02) [2,3] O2N NO 2
NO 2 OH
1.70 7 3,5-Dinitrophenol C6H4N2O5 184.10 1.64 (3.65) [2,3]
O2N NO 2 OH
NO 2 1.68 8 2,3-Dinitrophenol C6H4N2O5 184.10 1.64 (2.50) [2,3]
NO 2 OH
NO 2 1.68 9 2,4-Dinitrophenol C6H4N2O5 184.10 1.64 (2.62) [2,3]
NO 2 50 Page 4 of 18 J Mol Model (2018) 24: 50
Table 2 (continued)
OH
1.67 10 3,4-Dinitrophenol C6H4N2O5 184.10 1.64 (1.95) [2,3] NO 2
NO 2 OH
O2N NO 2 1.76 11 2,4,6-Trinitrophenol (Picric C6H3N3O7 229.10 1.76 (0.0) acid) [2,3]
NO 2 OH
O2N NO 2 1.82 12 2,4,6-Trinitrobenzene-1,3-diol C6H3N3O8 245.10 1.79 (1.67) (Styphnic acid) [2,3] OH
NO 2
CH3
NO 2 1.52 13 1-Methyl-2,4-dinitrobenzene C7H6N2O4 182.13 1.52 (0.0) [2,3]
NO 2
CH3
O2N NO 2 1.65 14 2-Methyl-1,3,5-trinitrobenzene C7H5N3O6 227.13 1.65 (0.0) (TNT) [2,3]
NO 2
NO 2
CH3 1.60 15 2,4-Dimethyl-1,3,5- C8H7N3O6 241.16 1.58 (1.26) trinitrobenzene [2,3] O2N NO 2
CH3
NO 2
3CH CH3 1.48 16 1,3,5-Trimethyl-2,4,6- C9H9N3O6 255.18 1.53 (-3.26) trinitrobenzene [2,3] O2N NO 2
CH3
NH2
NO 2 1.61 17 2,4-Dinitroaniline C6H5N3O4 183.22 1.58 (1.89) [2,3]
NO 2
NH2
O2N NO 2 1.76 18 2,4,6-Trinitroaniline (TNA) C6H4N4O6 228.12 1.71 (2.92) [2,3]
NO 2 JMolModel(2018)24:50 Page 5 of 18 50
Table 2 (continued)
NH2 NO O2N 2 1.86 19 2,3,5,6-Tetranitroaniline C6H3N5O8 273.12 1.82 1.80 (3.33) [2,3]
O2N NO 2
NH2
O2N NO 2 1.83 20 2,4,6-Trinitrobenzene-1,3- C6H5N5O6 243.13 1.80 (1.66) diamine (DATB) [2,3] NH2
NO 2
NO 2
2NH NH2 1.93 21 2,4,6-Trinitrobenzene-1,3,5- C6H6N6O6 258.15 1.79 (7.82) triamine (TATB) [2,3] O2N NO 2
NH2 OH
O2N NO 2 1.69 22 3-Methyl-2,4,6-trinitrophenol C7H5N3O7 243.13 1.68 (0.59) [2,3] CH3
NO 2
OCH 3
O2N NO 2 1.61 23 2-Methoxy-1,3,5-trinitrobenzene C7H5N3O7 243.13 1.68 (-4.16) [2,3]
NO 2
OCH 2CH 2ONO 2
O2N NO 2 1.68 24 2-(2,4,6-Trinitrophenoxy)ethyl C8H6N4O10 318.15 1.72 (-2.32) nitrate [2,3]
NO 2
OCH 2CH 2ONO 2
NO 2 1.60 25 2-(2,4-Dinitrophenoxy)ethyl C8H7N3O8 273.16 1.64 (-2.43) nitrate [2,3]
NO 2
N3
O2N NO 2 1.81 26 1,3,5-Triazido-2,4,6- C6N12O6 336.14 1.88 (-3.72) trinitrobenzene [2,3] N3 N3
NO 2
NO 2 OH OH 1.89 27 2,4,6-Trinitrobenzene-1,3,5-triol C6H3N3O9 261.10 1.81 (4.41) [2,3] O2N NO 2 OH 50 Page 6 of 18 J Mol Model (2018) 24: 50
Table 2 (continued)
3CH NO 2 N
O2N NO 2 N N 1.73 28 -methyl- ,2,4,6- C7H5N5O8 287.14 1.73 (0.0) tetranitroaniline (Tetryl) [2,3]
NO 2
NH2
N NH2
O2N NO 2 1.79 29 2-(2,4,6- C7H6N6O6 270.16 1.77 (1.12) Trinitrophenyl)guanidine [25]
NO 2
NHNH 2
NO 2 1.65 30 (2,4-Dinitrophenyl)hydrazine C6H6N4O4 198.14 1.57 (5.09) [26]
NO 2
O2N C2H5 N
O2N NO 2 N N 1.63 31 -ethyl- ,2,4,6-tetranitroaniline C8H7N5O8 301.17 1.67 (-2.39) (Ethyl tetryl) [27]
NO 2
O2N CH 2CH 2ONO 2 N
O N NO 2-[Nitro(2,4,6- 2 2 1.75 32 trinitrophenyl)amino]ethyl C8H6N6O11 362.17 1.76 (-0.56) [27] nitrate
NO 2 CN 1.28 33 Benzene-1,3-dicarbonitrile C8H4N2 128.13 1.36 (-5.88) [28] CN
- O + O2N N N 1.63 34 2-Diazonio-4,6-dinitrophenolate C6H2N4O5 210.10 1.74 (-6.32) [2,3]
NO 2
O2N NO 2 NO 2 E 1.74 35 1,1'-( )-Ethene-1,2- C14H6N6O12 450.23 1.71 (1.75) diylbis(2,4,6-trinitrobenzene) [2,3]
NO 2 O2N NO 2 JMolModel(2018)24:50 Page 7 of 18 50
Table 2 (continued)
O2N NO 2
NO 2 N 1.82 36 2,4,6-Trinitro- -(2,4,6- NH C12H5N7O12 439.21 1.75 (4.0) trinitrophenyl)aniline [29] NO 2
O2N NO 2
O2N NO 2
NO 2 1.70 37 1,1'-Oxybis(2,4,6- O C12H4N6O13 440.19 1.78 (-4.49) trinitrobenzene) [2,3] NO 2
O2N NO 2
O2N NO 2 NO 2 E N 1.79 38 ( )-Bis(2,4,6- N C12H4N8O12 452.21 1.77 (1.12) trinitrophenyl)diazene [30]
NO 2 O2N NO 2 NH
1.42 39 3-Nitro-N-(3-nitrophenyl)aniline C12H9N3O4 259.22 1.45 (-2.06) [2,3]
NO 2 NO 2
O2N NO 2
NH NNH 3,5-Dinitro-N,N'-bis(2,4,6- 1.75 O N O2N NO 40 trinitrophenyl)pyridine-2,6- 2 NO 2 C17H7N11O16 621.30 1.75 (0.0) 2 [31] diamine
NO NO 2 2 O OO O 1.34 41 Diphenylperoxyanhydride C14H10O4 242.22 1.37 (-2.18) [32]
O N 1.12 42 1,3-Diethyl-1,3-diphenylurea C17H20N2O 268.35 1.18 (-5.08) 5C2 NH C2H5 [27]
CH CH O 3 3
2,2'-[Propane-2,2- 1.17 43 diylbis(benzene-4,1- O O C21H24O4 340.41 1.22 (-4.09) [27] diyloxymethanediyl)]dioxirane
O 50 Page 8 of 18 J Mol Model (2018) 24: 50
Table 2 (continued)
NH 1.16 44 N-phenylaniline C12H11N 169.22 1.19 (-2.52) [27]
NO 2 O2N NH2
1.79 O N NO 45 2,2',4,4',6,6'-Hexanitrobiphenyl- 2 2 C12H6N8O12 454.22 1.86 (-3.76) 3,3'-diamine [27]
2NH NO 2 O2N
NO 2 NO 2
1.80 46 1,4,5,8-Tetranitronaphthalene C10H4N4O8 308.16 1.70 (5.88) [33]
NO 2 NO 2
NO 2 NO 2
NH2 1.78 47 1,4,5,8-Tetranitronaphthalene- C10H6N6O8 338.19 1.79 (-0.55) 2,6-diamine [33] 2NH
NO 2 NO 2
- O O N + + N - N O O 1.90 48 Benzotrifuroxan (BTF) C6N6O6 252.10 1.86 (2.15) N [34] N + N O - O
N O N H 2 N 1.61 49 1-(3,4-Dinitrophenyl)-1 -1,2,4- C8H5N5O4 235.16 1.60 (0.62) triazole N [35]
O2N
O2N
N 1.57 50 1-(4-Methyl-3,5-dinitrophenyl)- 3CH N C H N O 249.18 1.54 (1.94) H 9 7 5 4 1 -1,2,4-triazole N [35]
O2N
NO 2
N O N 1.51 51 1-(5-Methyl-2,4-dinitrophenyl)- 2 N C H N O 249.18 1.54 (-1.94) H 9 7 5 4 1 -1,2,4-triazole N [35]
3CH
O2N
N 1.57 52 1-(2-Methyl-3,5-dinitrophenyl)- N C H N O 249.18 1.54 (1.94) H 9 7 5 4 1 -1,2,4-triazole N [35]
O2N CH3
NO 2
N 1.59 53 1-(5-Methoxy-2,4- O2N N C H N O 265.18 1.57 (1.27) H 9 7 5 5 dinitrophenyl)-1 -1,2,4-triazole N [35]
H3CO JMolModel(2018)24:50 Page 9 of 18 50
Table 2 (continued)
NO 2
N 1.57 54 1-(3-Methoxy-2,6- N C H N O 265.18 1.57 (0.0) H 9 7 5 5 dinitrophenyl)-1 -1,2,4-triazole N [35]
H3CO NO 2
O2N
N H 1.65 55 2,4-Dinitro-6-(1 -1,2,4-triazol- N C8H6N6O4 250.17 1.59 (3.77) 1-yl)aniline N [35]
O2N NH2
NO 2 N N 1.74 56 1-(2,4-Dinitrobenzyl)-4-nitro- N C9H6N6O6 294.18 1.64 (6.09) 1H-1,2,3-triazole [36] O2N NO 2
NO 2 N H N 1.54 57 1-(2,4-Dinitrobenzyl)-1 -1,2,3- C9H7N5O4 249.18 1.54 (0.0) triazole N [36]
O2N
O2N N N N H 1.62 58 1-(3,5-Dinitrobenzyl)-1 -1,2,3- C9H7N5O4 249.18 1.54 (5.19) triazole [36]
NO 2
O2N N N 1.54 H N 59 1-(3,4-Dinitrobenzyl)-1 -1,2,3- C9H7N5O4 249.18 1.54 (0.0) triazole [36] O2N
O2N N N N 1.49 60 1-(4-Methoxy-3,5- C10H9N5O5 279.21 1.52 (-1.97) dinitrobenzyl)-1H-1,2,3-triazole H3CO [36]
NO 2
H3CO NO 2 N N 1.52 N 61 1-(3-Methoxy-2,6- C9H7N5O5 265.18 1.57 (-3.18) dinitrophenyl)-1H-1,2,3-triazole [36]
NO 2
H3CO N 1-(5-Methoxy-2,4- N 1.58 O N N 62 dinitrophenyl)-1H-1,2,3-triazole 2 C9H7N5O5 265.18 1.57 (0.63) [36] [35]
NO 2
O2N OCH 3 N N 1.54 N 63 1-(2-Methoxy-3,5- C9H7N5O5 265.18 1.57 (-1.91) dinitrophenyl)-1H-1,2,3-triazole [36]
O2N 50 Page 10 of 18 J Mol Model (2018) 24: 50
Table 2 (continued)
NO 2 N 3 N 1.77 5-Azido-4,6-dinitro-1H- 64 N C6H2N8O4 250.13 1.76 (0.56) benzotriazole [37] O N N 2 H
NO 2 N 1.54 CH N 65 2-(4-Methyl-2,6-dinitrophenyl)- 3 C9H7N5O4 249.18 1.54 (0.0) 2H-1,2,3-triazole N [38]
NO 2
NO 2 N 1.55 O N N 66 2-(5-Methyl-2,4-dinitrophenyl)- 2 C9H7N5O4 249.18 1.54 (0.64) 2H-1,2,3-triazole N [38]
3CH
NO 2 N 1.57 N 67 2-(3-Methoxy-2,6- C9H7N5O5 265.18 1.57 (0.0) dinitrophenyl)-2H-1,2,3-triazole N [38]
H3CO NO 2
NO 2 N 1.57 O N N 68 2-(5-Methoxy-2,4- 2 C9H7N5O5 265.18 1.57 (0.0) dinitrophenyl)-2H-1,2,3-triazole N [38]
H3CO
NO 2 N 1.63 CH N 69 2-(4-Methyl-2,5-dinitrophenyl)- 3 C9H6N6O6 294.18 1.64 (-0.60) 4-nitro-2H-1,2,3-triazole N [38] NO 2 O2N
NO 2 N 1.61 CH N 70 2-(4-Methyl-2,6-dinitrophenyl)- 3 C9H6N6O6 294.18 1.64 (-1.82) 4-nitro-2H-1,2,3-triazole N [38] NO 2 NO 2
O2N N 2-(4-Methoxy-3,5- 1.70 H CO N 71 dinitrophenyl)-4-nitro-2H-1,2,3- 3 C9H6N6O7 310.18 1.66 (2.40) [38] triazole N NO 2 O2N
NO 2 N 2-(3-Methoxy-2,4,6- 1.72 O N N 72 trinitrophenyl)-4-nitro-2H-1,2,3- 2 C9H5N7O9 355.18 1.74 (-1.14) [38] triazole N NO 2 H3CO NO 2
NH NNH N,N'-bis(2,4,6- 1.69 O N O2N NO 73 trinitrophenyl)pyridine-2,6- 2 NO 2 C17H9N9O12 531.31 1.66 (1.80) 2 [31] diamine (pre-PYX)
NO NO 2 2
NH2
NC NO 2 1.40 3-Amino-5-(furan-2-yl)-2- 74 O C17H11N3O3 305.29 1.39 (0.71) nitrobiphenyl-4-carbonitrile [39]
% Error values are given in parentheses JMolModel(2018)24:50 Page 11 of 18 50
Table 3 Predicted densities of energetic salts and cocrystals containing one or more benzene rings in their molecular structures Expt. Calculated MW Compd. Name Structure MF Density Density (g/mol) (g/cm3) (g/cm3) + - NH O 4 O N NO 2 2 1.72 75 Ammonium picrate C6H6N4O7 246.13 1.68 (2.38) [2,3]
NO 2
NO 2 O2N
- N NO 2 O2N 1.79 76 Guanylurea dipicrylamide NO O N C14H11N11O13 541.31 1.79 (0.0) 2 2 [40] O + NH NH2
2NH 2NH
O2N NO 2
+ + NH - - NH4 Ammonium salt of 2,6- 4 N NN 1.72 O N O2N NO 77 bis(picrylamino)-3,5- 2 NO 2 C17H13N13O16 655.36 1.69 (1.77) 2 [40] dinitropyridine
NO NO 2 2
O2N NO 2
+ + HNHO NH OH 3 - - 3 Hydroxylammonium salt of N NN 1.71 O N O2N NO 78 2,6-bis(picrylamino)-3,5- 2 NO 2 C17H13N13O18 687.36 1.82 (-6.04) 2 [40] dinitropyridine
NO NO 2 2
N N
+ + N N H H 1,1’- - - O O 1.52 79 Methylenebis(imidazolium) C H N O 606.37 1.62 (-6.17) O N NO 19 14 10 14 O2N NO 2 2 2 [41] dipicrate
NO NO 2 2
N N
+ + N N CH CH 1,1’ - 3 3 - -Methylenebis(3- O O 1.63 80 C21H18N10O14 634.43 1.58 (3.16) methylimidazolium) dipicrate O N NO [41] O2N NO 2 2 2
NO NO 2 2 50 Page 12 of 18 J Mol Model (2018) 24: 50
Table 3 (continued)
NN NN
+ + N N CH CH 1,1’ - 3 3 - -Methylenebis(4- O O 1.67 81 C19H16N12O14 636.40 1.62 (3.08) methyltriazolium) dipicrate O N NO [41] O2N NO 2 2 2
NO NO 2 2
NO 2 O2N
- N NO 2 O2N
NO 2 O2N + Ethylenediammonium bis- + NH 1.75 82 NH 3 C26H18N16O24 938.52 1.80 (-2.77) dipicrylamine 3 [42]
NO 2 O2N
- N NO 2 O2N
NO 2 O2N
NO 2 O2N
- N NO 2 O2N
1,3-Diaminoguanidinium- 1.76 NO 2 O2N 83 C13H12N12O12 528.31 1.78 (-1.12) dipicrylamine + [42] NH2
NH NH
NH2 NH2
- O NH O2N NO 2 2 5-Amino-1-methyl-1H- 1.71 84 CH + C8H8N8O7 328.20 1.65 (3.63) tetrazolium picrate 3 N NH [43] N N NO 2
- O NH O2N NO 2 2 5-Amino-1,4-dimethyl-1H- 1.63 85 CH + CH C9H10N8O7 342.22 1.60 (1.87) tetrazolium picrate 3 N N 3 [43] N N NO 2
- O NH2 O2N NO 2 5-Amino-1,3-dimethyl-1H- 1.63 3CH 86 N N C9H10N8O7 342.22 1.60 (1.87) tetrazolium picrate + [43] N N CH NO 2 3 JMolModel(2018)24:50 Page 13 of 18 50
Table 3 (continued)
- O
NH2 O2N NO 2 3,4,5-Triamino-1,2,4- N 1.74 87 2NH NH2 C8H9N9O7 343.21 1.75 (-0.57) triazolium picrate [43] + NN H NO 2
- O NH2 O2N NO 2 3,4,5-Triamino-1-methyl- N 1.68 NH NH 88 2 2 C9H11N9O7 357.24 1.71 (-1.75) 1,2,4-triazolium picrate [43] + NN CH NO 2 3
- O H O2N NO 2 + 1,2,4-Triazolium picrate N 1.77 89 C8H6N6O7 298.17 1.67 (5.98) N [41] N H NO 2
- + O NH3 N O2N NO 2 3-Amino-1,2,4-triazolium 1.60 90 N C8H7N7O7 313.18 1.66 (-3.61) picrate N [41] H
NO 2
- O H + NN O2N NO 2 4-Amino-1,2,4-triazolium 1.64 91 C8H7N7O7 313.18 1.66 (-1.20) picrate N [41]
NH2 NO 2
- O + OH O2N NO 2 1.72 92 Uronium picrate C7H7N5O8 289.16 1.79 (-3.91) 2NH NH2 [44]
NO 2
- O H NH2 + O2N NO 2 3,5-diamino-1,2,4-triazolium N 1.76 93 C H N O 328.20 1.76 (0.0) N 8 8 8 7 picrate NH [44] 2 N H NO 2
- H O + 2NH N NH2 O2N NO 2
6-phenyl-2,4-diamino-1,3,5- N N 1.62 94 C15H12N8O7 416.31 1.64 (-1.21) triazinium picrate [44] NO 2 50 Page 14 of 18 J Mol Model (2018) 24: 50
Table 3 (continued)
- O H + O2N NO 2 3-Hydrazino-4-amino-1,2,4- N N 1.73 95 C8H9N9O7 343.21 1.75 (-1.14) triazolium picrate NHNH [45] N 2
NH2 NO 2
+ + NH3 3NH - - O O Ethylenediaminium-2- 1.49 96 O N NO C14H18N4O6 338.32 1.48 (0.67) nitrophenolate salt 2 2 [46]
+ + NH3 3NH - - O O
Ethylenediaminium-2,4- O2N NO 2 1.59 97 C14H16N6O10 428.31 1.63 (-2.45) dinitrophenolate salt [46]
NO 2 NO 2 + + NH NH3 - 3 - O O
Ethylenediaminium-2,4,6- O2N NO 2 O2N NO 2 1.73 98 C14H14N8O14 518.31 1.75 (-1.14) trinitrophenolate salt [46]
NO 2 NO 2
NH N - N N Guanidinium 3-(picrylamino)- O N NO 1.70 99 2NH 2 2 C9H10N10O6 354.24 1.71 (-0.58) 1,2,4-triazole + [47] C NH2
2NH
NO 2 N N NH 2 N 1-(2,4,6-trinitrophenyl)-1H- 1.56 CH O2N NO 2 100 1,2,4-triazol-5-amine: 3 C11H12N8O7 368.26 1.56 (0.0) [47] Dimethylformamide crystal NCH3 O
NO 2 - O + 2NH NH2 O2N NO 2 1.54 101 Benzimidamidium picrate C13H11N5O7 349.26 1.53 (0.65) [48]
NO 2 JMolModel(2018)24:50 Page 15 of 18 50
Table 3 (continued) - O 3CH CH3 2-isopropyl-6- O2N NO 2 1.44 102 methylpyrimidin-1,3-diium-4- + + C14H15N5O8 381.30 1.49 (-3.35) NH NH [48] olate picrate - 3CH O NO 2
- O OH + O N NO NH NH N-(amino(pyrimidin-2- 2 2 2 1.69 103 yl)methylene)hydroxyl C11H9N7O8 367.23 1.62 (4.32) NN [48] ammonium picrate
NO 2
CH3 NO 2 O2N NO 2 2,4,6-trinitrotoluene: 1- 1.53 104 C17H12N4O8 400.30 1.51 (1.32) Nitronaphthalene cocrystal [49]
NO 2 OH NO 2 O2N NO 2 Picric acid: 1- 1.53 105 C16H10N4O9 402.27 1.56 (-1.92) Nitronaphthalene cocrystal [49]
NO 2
CH3 NO 2 O2N NO 2 2,4,6-Trinitrotoluene: 1,3,5- 1.64 106 C13H8N6O12 440.24 1.69 (-2.95) Trinitrobenzene cocrystal [50]
O2N NO 2 NO 2
CH O - 3 N O NH + - N + O N 2,4,6-Trinitrobenzene O2N NO 2 O 1.80 107 methylamine: Benzotrifuroxan C13H6N10O12 494.25 1.74 (3.44) N [51] cocrystal N + O N NO - 2 O
O - N O NH + 2 - N + O N O N NO 2,4,6-Trinitroaniline: 2 2 O 1.88 108 C12H4N10O12 480.22 1.78 (5.61) N Benzotrifuroxan cocrystal N [51] + O N - NO 2 O
O - N O CH + 3 - N + O N O N NO 2,4,6-Trinitrotoluene: 2 2 O 1.80 109 C13H5N9O12 479.23 1.75 (2.85) N Benzotrifuroxan cocrystal N [51] + O N - NO 2 O 50 Page 16 of 18 J Mol Model (2018) 24: 50
Table 3 (continued)
O - N O + - N + O N O N NO 1,3,5-Trinitrobenzene: 2 2 O 1.80 110 C12H3N9O12 465.21 1.80 (0.0) N Benzotrifuroxan cocrystal N [51] + O N - NO 2 O
CH3
O2N NO 2 2,4,6-Trinitrotoluene: 1.49 111 C17H13N3O6 355.30 1.44 (3.47) Naphthalene cocrystal [52]
NO 2
CH3
O2N NO 2 2,4,6-Trinitrotoluene: 1.51 112 C21H15N3O6 405.37 1.41 (7.09) Anthracene cocrystal [52]
NO 2
CH3
O2N NO 2 2,4,6-Trinitrotoluene: 1.48 113 C21H15N3O6 405.37 1.41 (4.96) Phenanthrene cocrystal [52]
NO 2
CH3
O2N NO 2 2,4,6-Trinitrotoluene: 1,2- NH2 1.57 114 C13H13N5O6 335.27 1.47 (6.80) Phenylenediamine cocrystal [52]
NH2 NO 2
CH3 OCH 3
O2N NO 2 2,4,6-Trinitrotoluene: 1,4- 1.50 115 C15H15N3O8 365.30 1.46 (2.73) Dimethoxybenzene cocrystal [52]
NO 2 OCH 3 NH CH3 2
O2N NO 2 2,4,6-Trinitrotoluene: 4- 1.57 116 C14H12N4O8 364.27 1.52 (3.28) Aminobenzoic acid cocrystal [52]
COOH NO 2 NH NH2 CH3 2
2,4,6-Trinitrotoluene: 4- O2N NO 2 1.52 117 Aminobenzoic acid (1:2) C21H19N5O10 501.41 1.56 (-2.56) [52] cocrystal COOH COOH NO 2 NH CH3 2 COOH O2N NO 2 2,4,6-Trinitrotoluene: 1.59 118 C14H12N4O8 364.27 1.52 (4.60) Anthranilic acid cocrystal [52]
NO 2
CH3 NO 2,4,6-Trinitrotoluene: O2N 2 1.54 119 Anthranilic acid (1:2) C21H19N5O10 501.41 1.56 (-1.28) 2NH [52] cocrystal COOH HOOC NH2 NO 2 % Error values are given in parentheses JMolModel(2018)24:50 Page 17 of 18 50
This is supported by the fact that 19 of the 21 compounds in 2. Tarver CM (1979) Density estimations for explosives and related Table S2 of the ESM presented errors of less than 4% in their compounds using the group additivity approach. J Chem Eng Data 24:136–145 predicted densities (entries 21 and 78 were the exception). 3. Keshavarz MH (2007) New method for calculating densities of nitroaromatic explosive compounds. J Hazard Mater 145:263–269 4. Stine J (1981) Report DE81032016. Los Alamos National Laboratory, Los Alamos Conclusions 5. Ammon HL (2008) Updated atom/functional group and atom-code volume additivity parameters for the calculation of crystal densities By considering the complexities involved in predicting the of single molecules, organic salts, and multi-fragment materials containing H, C, B, N, O, F, S, P, Cl, Br, and I. 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Keshavarz MH (2009) Novel method for predicting densities of densities that show absolute deviations of less than 0.05 g/cm3 polynitro arene and polynitro heteroarene explosives in order to – and errors of less than 4% with respect to the experimental evaluate their detonation performance. J Hazard Mater 165:579 588 densities of most benzene-containing explosives. The comput- 9. Ye C, Shreeve JM (2007) Rapid and accurate estimation of densities ed densities could be used to calculate detonation performance of room-temperature ionic liquids and salts. J Phys Chem A 111: values within acceptable error. This approach is, however, 1456–1461 restricted to CHNO-based explosives containing one or more 10. Ye C, Shreeve JM (2008) New atom/group volume additivity meth- od to compensate for the impact of strong hydrogen bonding on benzene rings, and using it leads to large errors in the calcu- densities of energetic materials. J Chem Eng Data 53:520–524 lated densities of compounds with nitrogen-rich backbones. 11. Hofmann DWM (2002) Fast estimation of crystal densities. Acta Further efforts are required to account for the influences of Crystallogr B57:489–493 geometric complexity and a nitrogen-rich backbone on the 12. Xiong Y, Ding J, Yu D, Peng C, Liu H, Hu Y (2011) Volumetric densities of energetic materials. connectivity index: a new approach for estimation of density of ionic liquids. Ind Eng Chem Res 50:14155–14161 13. Beaucamp S, Marchet N, Mathieu D, Agafonov V (2003) Calculation of the crystal densities of molecular salts and hydrates using additive volumes for charged groups. Acta Crystallogr B59: Supporting information 498–504 14. Kim CK, Cho SG, Li J, Park BH, Kim CK (2016) Prediction of A comparison of the densities estimated in the present work crystal density and explosive performance of high-energy-density with experimental values and data in previous reports is pro- molecules using the modified MSEP scheme. Bull Kor Chem Soc 37:1683–1689 vided in Table S1. A comparison of the densities estimated 15. Gutowski KE, Holbrey JD, Rogers RD, Dixon DA (2005) using Eqs. 2 and 3 with corresponding experimental values is Prediction of the formation and stabilities of energetic salts and given in Table S2. Tables S3 and S4 list the calculated atomic ionic liquids based on ab initio electronic structure calculations. J and total volumes (nm3) of neutral explosives, energetic salts, Phys Chem B 109:23196–23208 and cocrystals. 16. Rice BM, Sorescu DC (2004) Assessing a generalized CHNO in- termolecular potential through ab initio crystal structure prediction. J Phys Chem B 108:17730–17739 Acknowledgements This work was supported by a grant from the DST- 17. Rice BM, Hare JJ, Byrd EFC (2007) Accurate predictions of crystal SERB, Government of India (Young Scientists, no. SB/FT/CS-110/ densities using quantum mechanical molecular volumes. J Phys 2014). Alka Devi thanks the CSIR for a research fellowship (no. 09/ Chem A 111:10874–10879 1050(0005) 2015-EMR-1). 18. Keshavarz MH, Pouretedal HR, Saberi E (2016) A simple method for prediction of density of ionic liquids through their molecular Compliance with ethical standards structure. J Mol Liquids 216:732–737 19. Zhao G, Lu M (2013) Crystal structures, infrared spectra, thermal Conflict of interest The authors declare no conflict of interest. stabilities and burning properties of RDX derivatives: a computa- tional study. Comput Theor Chem 1018:13–18 20. Moxnes JF, Hansen FK, Jensen TL, Sele ML, Unneberg E (2017) A computational study of density of some high energy molecules. 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