Computational Screening of Nitrogen-Rich Energetic Salts Based on

Subscriber access provided by MOSCOW STATE UNIV

Article

Computational Screening of Nitrogen-Rich Energetic Salts Based on Substituted Triazine Vikas D Ghule J. Phys. Chem. C, Just Accepted Manuscript • DOI: 10.1021/jp405631c • Publication Date (Web): 31 Jul 2013 Downloaded from http://pubs.acs.org on August 4, 2013

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

The Journal of Physical Chemistry C is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

The Journal of Physical Chemistry

Computational Screening of Nitrogen-Rich Energetic Salts Based on Substituted Triazine Vikas D. Ghule,*

Advanced Center for Research in High Energy Materials, University of Hyderabad, Hyderabad-500046, India.

Abstract In this work, 110 energetic salts were designed and studied for their applications in energetic materials. Density functional theory method was used to predict the heats of formation (HOFs), electronic structure, and energetic properties of a series of triazine-based ionic and non-ionic compounds. It is observed that the –N3 group, triazole, tetrazole, triazine, and tetrazine are effective structural units for increasing the HOFs in the designed compounds. The HOFs of cations, anions, and lattice energies of the salts were calculated separately to obtain the HOFs of the salts based on Born-Haber cycle. The combination of three cations within same framework is very useful for improving HOFs of energetic salts. Similarly, presence of the –NO2 and –NHNO2 groups in same structure found helpful in improving densities through strong inter- and intra-molecular hydrogen bonding. The detonation velocities and detonation pressures of the salts were predicted by the Kamlet-Jacobs equations using calculated densities and HOFs. The calculated energetic properties indicate that the combination of suitable anion and cation species is useful for modifying their detonation properties and oxygen balances (OB). The predicted results reveal that most of compounds outperform RDX and TATB and may be considered as potential candidate of high energy materials. These results provide basic information for molecular design of novel high energetic salts.

Key words: Energetic salts, Triazine, Energetic materials, Lattice energy, Heat of formation, Detonation velocity.

ACS Paragon Plus Environment


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 2 of 27

Introduction Over the past several years, there has been a growing interest in the development of environmentally friendly energetic materials for military and civilian applications.1-4 Among this development, energetic materials composed of heterocyclic backbone are on the forefront of the research. These high-nitrogen compounds form a unique class of energetic materials whose energy is derived from their very high heats of formation rather than from the combustion of hydrocarbon skeleton. The high heat of formation is directly attributable to the large number of energetic N–N and C–N bonds in this compounds.5-7 In addition, heterocycles that contain large amounts of nitrogen are typically relatively dense, and the smaller amounts of hydrogen and carbon enhance good oxygen balance. In recent reports, the syntheses and design of new materials continues to focus on the heterocyclic-based energetic salt as they often exhibit low vapor pressures and higher density than their atomically similar nonionic analogues.8-16 s-Triazine is an intriguing heterocycle for high energy materials and possesses a high degree of thermal stability.17,18 With higher heats of formation and better performance, most of the derivatives of triazine are reported for energetic applications. Hydrogen atoms of triazine can be substituted with various energetic functional groups. In general, the good candidates for energetic materials contain high nitrogen/oxygen content which arises from their molecular backbone and typical energetic groups such as azo or azido groups.19-22 The nitrogen-rich azide compounds considered as energy power house because they can release enormous amounts of energy, which is due to the average bond energies: N–N (160 kJ/mol), N=N (418 kJ/mol) and N≡N (954 kJ/mol).23 In addition, the presence of nitro groups greatly improves the density results in increased detonation performance properties (pressure and velocity) that are related to the square of or proportional to the density.24-26 Normally more energetic groups

or

explosophores

enhance

the

nitrogen/oxygen

percentage

while

concomitantly increasing the sensitivity of the energetic materials. These groups are also supposed to be the trigger linkages in the energetic materials and affect their sensitivities and/or stabilities. Recently, Shreeve et al.27 reported 6-nitroamino-2,4-diazido[1,3,5]-triazine (NADAT) and its monoanionic energetic salts. These salts show good densities, moderate thermal stabilities, and better detonation performance, which were similar or higher than that of conventional explosives such as TNT or TATB. This work


Page 3 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


prompted us to study the energetic properties of various salts of the substituted triazine anion. Aiming at finding new super high energy density materials with high detonation velocity and pressure, triazine substituted with –N3, –NHNO2, –NO2, – NH2 groups and their salts were designed by replacing the proton of nitramino group. All designed compounds are of CHNO-type and their decomposition products expected predominantly in the generation of CO2, H2O and N2 and lead to promising candidates for green and environmentally friendly energetic materials. In this study, we reported a systematic study of the heats of formation (HOFs), density, and detonation performance of a series of energetic triazine salts using density functional theory (DFT).

Computational details All computations were performed with Gaussian 03 package at B3PW91 method with 6-31G(d,p) basis set.28 The structural parameters were allowed to be optimized and no constraints were imposed on molecular structure during optimization process. All optimized structures were characterized to the true local energy minima on potential energy surfaces without imaginary frequencies. Figure 1 presents the non-ionic compounds selected for anionic moiety. The oxygen balance (OB) is used to indicate the degree to which an explosive can be oxidized and oxygen is needed in a molecule to oxidize it completely into their gaseous reaction products. OB is used in prediction of detonation velocity, detonation pressure, chemical energy of detonation, and decomposition products. The molecule is said to have a positive (negative) oxygen balance if it contains more (less) oxygen than is needed for complete combustion. OB (%) for an explosive containing the general formula CaHbNcOd with molecular mass M can be calculated as,

OB(%) =

(d − 2a − 0.5b) X 1600 M

(1)

In previous studies, isodesmic reactions have been successfully employed to estimate the HOFs from the total energies obtained from ab initio calculations.29-32 Therefore, isodesmic reactions are designed in which the basic structural units were retained to minimize errors. The isodesmic reactions used for the prediction of gasphase HOF (HOFGas) of designed compounds are shown in Figure 2. The total energy



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 4 of 27

(E0), zero point energy (ZPE), and thermal corrections (∆HT) for reference compounds selected in isodesmic reactions and for ionic species are listed in Supporting Information. For estimation of the potential performance of the energetic material, it is also significant to calculate their solid-phase HOF (HOFSolid) because it is related directly with the detonation characteristics. According to Hess’ law, HOFSolid can be obtained from the HOFGas and heat of sublimation (HOFSub):

HOFSolid = HOFGas - HOFSub

(2)

Politzer et al.33-35 reported that the HOFSub can correlate well with the molecular surface area and the electrostatic interaction index for energetic compounds. The HOFSub can be evaluated by the Byrd and Rice method36 in the framework of the Politzer approach,33,37 using the following empirical relation,

2 0.5 HOFSub = β1A 2 + β 2 (vσ tot ) + β3

(3)

Where A is the area of the isosurface of 0.001 electrons/bohr3 electronic density, ν indicates the degree of balance between the positive and negative surface potentials,

σ tot2 is a measure of variability of the electrostatic potential, and β1, β2, and β3 are determined through a least-squares with the experimental HOFSolid of a selected set of known materials.36 Surface area, degree of balance between the positive and negative surface potentials and variability of the electrostatic potential are calculated using WFA program.38 Based on the Born–Haber cycle (shown in Figure 3), the heat of formation of an ionic compound can be simplified by subtracting the lattice energy of the salt (HL) from the total heat of formation of salt i.e. sum of the heats of formation of the cation and anion as shown in equation (4).

HOF (salt, 298 K) = HOF (cation, 298 K) + HOF (anion, 298 K) - HL

(4)

Lattice potential energy is the energy associated with the process in which a crystalline solid lattice, MpXq is converted into its constituent gaseous ions, pMq+ (g) and qXp− (g). The lattice energy can be predicted with reasonable accuracy by using Jenkins’ equation (5).39


Page 5 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


H L = U POT + [ p(

nM n - 2) + q( X - 2)]RT 2 2

(5)

where nM and nX depend on the nature of the ions Mp+ and Xq-, respectively, and are equal to 3 for monoatomic ions, 5 for linear polyatomic ions, and 6 for nonlinear polyatomic ions. When lattice potential energy (UPOT), is incorporated and made part of a Born–Haber cycle, it needs to be converted into a lattice enthalpy term. This lattice enthalpy (HL), involves correction of the UPOT term by an appropriate number of RT terms. The UPOT (kJ mol-1) can be predicted from four different equations (6-9) as suggested by Jenkins et al.40-42 using following equations,

U POT = AI ( 2VI )1/ 3

U POT = B( I 4

(6)

ρ 1/ 3 M

(7)

)

U POT = γ ( Mρ )1/ 3 + δ

(8)

U POT = 2 I [α (V) −1/ 3 + β ]

(9)

In above equations (6-9), I is the ionic strength factor, where I = 1/2Ʃnizi2. Here ni is the number of ions in the formula unit having a charge zi. For the salts with 3:1 charge ratio (cation:anion) listed in this work, the ionic strength, I=6. ρ is the density (g cm3

), V is the estimated volume of ionic material (nm3), and M is the chemical formula

mass of the ionic material (g mol-1). The coefficients A (121.4 kJ mol-1), B (1291.7 kJ mol-1), γ (2342.6·I kJ mol-1.cm), δ (55.2·I kJ mol-1) and generalised parameters α and β for salts (3:1) are 138.7 kJ mol-1.nm and 27.6 kJ mol-1, respectively, taken from Ref. 40. Equation (6) is normally employed for salts likely to have lattice energy greater than 5000 kJ mol-1 but it seems to work quite well in this case and for these materials. The empirical Kamlet-Jacobs24-26 equations were employed to estimate the values of detonation velocity (D) and detonation pressure (P) for the high energy materials containing C, H, O and N as following equations:



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 6 of 27

D = 1.01( NM 0.5Q 0.5 ) 0.5 (1 + 1.30ρ )

(10)

P = 1.55ρ 2 NM 0.5Q 0.5

(11)

where in above equations D is detonation velocity (km/s), P is detonation pressure (GPa), N is moles of gaseous detonation products per gram of explosives, M is average molecular weights of gaseous products, Q is chemical energy of detonation (cal/g) defined as the difference of the HOFs between products and reactants, and ρ is the density of explosive (g/cm3).

Results and discussion The aim of developing energetic salts is to achieve higher performance for real applications. Computational design of new energetic salts at molecular level based on pairing of selective energetic cations and anions allows for producing energetic salts with diverse physiochemical properties. Often, their properties are manipulated by making structural modifications. Therefore, the optimization of molecules with high energy and density to achieve higher performance for real applications is the primary step for searching high energy density materials. The triazine derivatives considered in this study tend to be acidic as a result of the electron withdrawing effect of triazine ring and the nitro group substituted on the NH. The designed compounds are organized in five different series including A, B, C, D, and E. Figure 4 presents the molecular frameworks and numbering of a series of anions and cations selected for energetic salts.

Heat of formation Heat of formation (HOF) is one of the most important parameter to estimate the performance of energetic material and indicates the energy content of corresponding material. Table 1 lists the total energies, ZPEs, thermal corrections and molecular surface properties for the non-ionic triazine derivatives. Unfortunately, no experimental HOFs are available for the designed non-ionic and ionic salts in the literature. The HOFSolid of the designed non-ionic compounds have been obtained through application of the Politzer approach as outlined in Computational Details. We investigated the effects of –NO2, -NHNO2, -NH2, and -N3 substituents on the HOFGas


Page 7 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


and HOFSolid of the compounds selected for anionic moiety. Table 2 presents the HOFs, HOFSub and relevant energetic properties of the triazine compounds selected for anionic moiety. It is seen that all the compounds have positive HOFSolid ( >100 kJ/mol), which is one of the necessary characteristics of energetic materials. Among these triazine derivatives, IV possesses the highest HOFSolid (419 kJ/mol). It is also observed that replacing the –NO2 with –NHNO2 groups on triazine backbone improves the HOF (II and V). However, replacement of –NO2 in II with –NH2 group reduces the HOFSolid of III by ~84 kJ/mol. The calculated HOFs of the designed salts are listed in Table 3-7. Among each series of salts, anionic species in combination with 5, 8, 13, 19, 21, and 22 cations possess higher HOFs than other salts. This is attributable to the presence of –N3 group, energetic triazole and tetrazole skeleton in cation and the increase of the number of energetic C-N bonds in these derivatives. It is noteworthy that the HOFs of designed isomers with the same number of nitro and amino groups are affected by the positions of C-NH2 and N-NH2 linkages. Thus, the replacement of 3-amino-1,2,4triazole cation (14) with 4-amino-4H-1,2,4-triazole cation (13) is very favorable for increasing its HOF greatly. It is seen that cations with tetrazine backbone (21 and 22) have highest HOFs in all series of salts. Comparing the HOFs of salts containing 4, 6, 7, and 8 cations reveals that the substitution of –NH2 can enhance the HOFs of the corresponding compounds. However, reverse effect found in case of 14 and 15 cations, where introduction of additional –NH2 group on triazole reduces the HOF of corresponding cations by ~30-65 kJ/mol. Figure 5 compares the effects of different cations and their combinations on HOF of the corresponding salts. It is obvious that the salts with 3:1 (cation:anion) charge ratio represent higher HOFs due to significant energy contribution from three cations. Overall, compared with other functional groups, the –N3 group has the highest impact on the HOFs of the cation and anion and is the first choice to increase the HOF of high energy materials. It is observed that with the increase in number of cations in salts improves their HOFs considerably. Further, it is also found that the transformation of the non-ionic molecules to corresponding cations or anions is very helpful for increasing their HOFs.

Density Density is the crucial factor for the prediction of performance and high density also desirable in terms of the amount of material can be packed into volume-limited



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

warhead or propulsion configurations. The Hofmann approach has been used to predict the densities in which an average atom volume calculated to estimate the cell volume for a title compound.43 Table 2 lists the densities of the substituted non-ionic triazine derivatives and Table 3-7 lists the densities of the designed salts. The densities for non-ionic compounds have been found to be in the range of 1.79−1.95 g/cm3. Among the designed compounds, the molecule III shows the lowest density (1.79 g/cm3) whereas I show the highest density of about 1.95 g/cm3. As evident from Table 2, when the substituent on triazine ring is –NO2 (II), an increase in the density value is observed compared to its corresponding –NH2 (III) and –N3 (IV) substituted derivatives. The presence of –NO2 groups and N−H in the molecular framework increases the opportunity for hydrogen bonding and may responsible for the better densities in the designed compounds. Figure 6 presents a comparison of the densities of the series A, B and E, in which –NO2 groups replaced with –NHNO2 groups and changes the cation:anion charge ratio from 1:1 to 2:1 to 3:1. In energetic salts, when the selected cations are 3, 5, 9, 17, 18, and 19 its corresponding salts have the largest densities among the salts with the same anion. Incorporating the –NO2 and –N3 group into the cationic species (cations 5, 9 and 17) enhances the density of corresponding salts, whereas for the substituent –CH3 or –NH2, the case is quite the contrary. Figure 7 represents the effect of –NO2 (series B), –NH2 (series C) and –N3 (series D) substituents on the densities of various salts. As expected in 2:1 (series B) and 3:1 (series E) salts, the increase in volume due to two and three cations, respectively decreases the density. The densities for the salts comprised of the 5-aminotetrazole cations (18, 19 and 20) shows decrement with incorporation of –NH2 and –CH3 groups. A similar trend is also observed in the guanidine salts (4, 6, 7 and 8), where introduction of –NH2 group in guanidine derivative reduces the density. We also noted that replacement of 1,2,4triazole with tetrazole show a great effect on the density. This shows that incorporating different cations alters the trend of the densities under the influence of different substituents. Overall, the presence of nitrogen-rich rings and nitro groups are essential to improve the density.

Detonation properties Detonation velocity and detonation pressure are two important performance parameters for an energetic materials. The calculated heats of detonation (Q),


Page 8 of 27

Page 9 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


detonation velocities (D), and pressures (P) for the starting non-ionic compounds and their corresponding ionic salts are given in Table 2-7. As evident from Table 2-7 that the –NO2 group is an effective substituent for increasing the density and thus the performance. Among the non-ionic compounds (I-V), I shows better detonation performance (D=9.05 km/s and P=38.07 GPa) over the other compounds due to the higher HOF, density and oxygen balance. The chemical energies of detonations for non-ionic compounds composed of nitramino groups are above 1082 cal/g indicate that the energetic densities of these derivatives are large. Among the designed salts, anion combined with 3, 9, 17, and 21 cations have chemical energy of detonation over 1100 cal/g. The performance of salts with 3, 9 and 17 cations is better due to the higher densities and oxygen balance (OB), which increases the concentration of detonation products like CO, CO2, and H2O. In the present study, the designed compounds composed only of the atoms C, H, N, and O and hence, N2(g), H2O(g), CO2(g), and C(s) are assumed as important detonation products, explained by Kamlet et al.24-26 and Politzer and Murray.34 Furthermore, assuming the detonation product composition to be N2(g)/H2O(g)/CO2(g)/C(s) gives overall quite satisfactory results for CHNO-based energetic compounds using an H2O−CO2 arbitrary decomposition scheme. A comparison of the detonation velocity and detonation pressure with TNT, TATB and RDX for the designed salts is displayed in Fig. 8. A3 (D = 8.88 km/s, P = 35.70 GPa), A9 (D = 8.64 km/s, P = 33.64 GPa) and A17 (D = 8.66 km/s, P = 34.12 GPa) possess a detonation performance comparable to that of RDX (D = 8.60 km/s, P = 33.92 GPa). The high performances of these compounds originate mainly from their high density and high oxygen balance. As observed, designed compounds exhibit better detonation performance than the TNT (D = 7.21 km/s, P = 22.49 GPa) whereas most of the designed compounds show higher/comparable performance than TATB (D = 8.13 km/s, P = 30.17 GPa). This indicates that the selective designed compounds could also be used as energetic compounds.

Conclusions In this work, we have studied the heats of formation, densities, and detonation properties for a series of energetic triazine-based nitrogen-rich salts by using the DFTB3PW91 method. Various cationic species have been combined with triazine anionic moieties to study the systematic structure-property relationship. The results reveal that



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

the –NO2 group is an effective substituent for increasing the densities of the ionic and non-ionic compounds. The substitution of the –NO2 and –N3 groups are found helpful in increasing the HOFs of the corresponding salts. The calculated detonation properties using Kamlet-Jacobs equation indicate that the NO2 and N3 explosophores are an effective structural unit for enhancing the detonation performance for the designed salts. Most of the designed salts exhibit good performance and are worthy of synthesis and further investigation. The predicted results for 110 energetic salts also expected to provide some useful information for the molecular design of novel highenergy salts.

Associated Content Supporting Information: The total energy (E0), zero point energy (ZPE), and thermal correction (∆HT) at the B3PW91/6-31G(d,p) level and experimental HOFGas for the reference compounds, cationic and anionic species. Selective structural parameters of the compound I-V. The electrostatic potentials for the 0.001 electron/bohr3 isosurfaces of electron density evaluated at the B3PW91 level of theory for compound I-V. Thermodynamic properties of compounds I-V. Information for the prediction of density for Series A-E salts.

Author Information Corresponding Author *e-mail: [email protected] (VDG)

Notes The author declare no competing ﬁnancial interest.

Acknowledgement The author thanks ACRHEM, University of Hyderabad for ﬁnancial support and computational facilities. The author also thanks Dr. K. Muralidharan, School of Chemistry, University of Hyderabad and Dr. S. Radhakrishnan, Mr. P. M. Jadhav, and Mr. R. S. Patil, High Energy Materials Research Laboratory, Pune, for their help and support.


Page 10 of 27

Page 11 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


References 1. Agrawal, J. P.; Hodgson, R. D. Organic Chemistry of Explosives; John Willey and Sons Ltd, The Atrium, Chichester, England, 2007. 2. Badgujar, D. M.; Talawar, M. B.; Asthana, S. N.; Mahulikar, P. P. Advances in Science and Technology of Modern Energetic Materials: an Overview. J. Hazard. Mater. 2008, 151, 289-305. 3. Sikder, A. K.; Sikder, N. A Review of Advanced High Performance, Insensitive and Thermally Stable Energetic Materials Emerging for Military and Space Applications. J. Hazard. Mater. 2004, 112, 1-15. 4. Gao, H.; Shreeve, J. M. Azole-based energetic salts. Chem. Rev. 2011, 111, 73777436. 5. Singh, R. P.; Verma, R. D.; Meshri, D. T.; Shreeve, J. M. Energetic Nitrogen-Rich Salts and Ionic Liquids. Angew. Chem. Int. Ed. 2006, 45, 3584–3601. 6. Steinhauser, G.; Klapötke, T. M. Green Pyrotechnics: A Chemists' Challenge. Angew. Chem. Int. Ed. 2008, 47, 3330–3347. 7. Wang, J. P.; Yi, W. B.; Cai, C. An Improved Method for the Preparation of Energetic Aminotetrazolium Salts. Z. Anorg. Allg. Chem. 2012, 638, 53–55. 8. Xue, H.; Gao, Y.; Twamley, B.; Shreeve, J. M. New Energetic Salts Based on Nitrogen-containing Heterocycles. Chem. Mater. 2005, 17, 191-198. 9. Huang, H.; Zhou, Z.; Liang, L.; Song, J.; Wang, K.; Cao, D.; Sun, W.; Bian, C.; Xue,

M.

Nitrogen-Rich

Energetic

Monoanionic

Salts

of

3,4-Bis(1ƩH-5-

tetrazolyl)furoxan. Chem. Asian J. 2012, 7, 707-714. 10. Sabate, C. M. ; Delalu, H.; Jeanneau, E. Energetic Hydrazine-Based Salts with Nitrogen-Rich and Oxidizing Anions. Chem. Asian J. 2012, 7, 2080-2089. 11. Wang, R.; Gao, H.; Ye, C.; Shreeve, J. M. Strategies Toward Syntheses of Triazolyl- or Triazolium-Functionalized Unsymmetrical Energetic Salts. Chem. Mater. 2007, 19, 144-152. 12. Klapotke, T. M.; Sabate, C. M. Bistetrazoles: Nitrogen-Rich, High-Performing, Insensitive Energetic Compounds. Chem. Mater. 2008, 20, 3629-3637. 13. Zeng, Z.; Wang, R.; Twamley, B.; Parrish, D. A.; Shreeve, J. M. PolyaminoSubstituted Guanyl-Triazole Dinitramide Salts with Extensive Hydrogen Bonding: Synthesis and Properties as New Energetic Materials. Chem. Mater. 2008, 20, 61766182.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

14. Thottempudi, V.; Shreeve, J. M. Synthesis and Promising Properties of a New Family of High-Density Energetic Salts of 5-Nitro-3-trinitromethyl-1H-1,2,4-triazole and 5,5′-Bis(trinitromethyl)-3,3′-azo-1H-1,2,4-triazole. J. Am. Chem. Soc. 2011, 133, 19982-19992. 15. Joo, Y. H.; Gao, H.; Zhang, Y.; Shreeve, J. M. Inorganic or Organic AzideContaining Hypergolic Ionic Liquids. Inorg. Chem. 2010, 49, 3282-3288. 16. Fendt, T.; Fischer, N.; Klapotke, T. M.; Stierstorfer, J. N-Rich Salts of 2-Methyl5-nitraminotetrazole: Secondary Explosives with Low Sensitivities. Inorg. Chem.

2011, 50, 1447-1458. 17. Turker, L.; Atalar, T.; Gumus, S.; Camur, Y. A DFT Study on Nitrotriazines. J. Hazard. Mater. 2009, 167, 440-448. 18. Carpel, P.; Walker, The Ring Index; American Chemical Society, Washington DC, New York, 1960. 19. Tao, G. H.; Guo, Y.; Parrish, D. A.; Shreeve, J. M. Energetic 1,5-Diamino-4Htetrazolium Nitro-substituted Azolates. J. Mater. Chem. 2010, 20, 2999–3005. 20. Meyer, R.; Kohler, J.; Homburg, A. Explosives; Wiley-VCH, Weinheim, 5th ed., 2002. 21. Akhavan, J. The Chemistry of Explosives; The Royal Society of Chemistry, Cambridge, 1998. 22. Cooper, P. W. Explosives Engineering; Wiley-VCH, New York, 1997. 23. Wu, B. D.; Zhou, Z. N.; Li, F. G.; Yang, L.; Zhang, T. L.; Zhang, J. G. Preparation, Crystal Structures, Thermal Decompositions and Explosive Properties of Two New High-nitrogen Azide Ethylenediamine Energetic Compounds. New J. Chem., 2013, 37, 646-653. 24. Kamlet, M. J.; Jacobs, S. J. Chemistry of Detonations. I. A Simple Method for Calculating Detonation Properties of C-H-N-O Explosives. J. Chem. Phys. 1968, 48, 23–35. 25. Kamlet, M. J.; Ablard, J. E. Chemistry of Detonations. II. Buffered Equilibria. J. Chem. Phys. 1968, 48, 36–42. 26. Kamlet, M. J.; Dickinson, C. Chemistry of Detonations. III. Evaluation of the Simplified Calculational Method for Chapman‐Jouguet Detonation Pressures on the Basis of Available Experimental Information. J. Chem. Phys. 1968, 48, 43–50.


Page 12 of 27

Page 13 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


27. Huang, Y.; Zhang, Y.; Shreeve, J. M. Nitrogen-Rich Salts Based on Energetic Nitroaminodiazido[1,3,5]triazine and Guanazine. Chem. Eur. J. 2011, 17, 1538–1546. 28. Frisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Montgomery, J. A.; Vreven, T., Jr.; Kudin, K. N.; Burant, J. C.; et al. Gaussian 03, revision A.1; Gaussian, Inc.: Pittsburgh, PA, 2003. 29. Ju, X. H.; Wang, X.; Bei, F. L. Substituent effects on heats of formation, group interactions, and detonation properties of polyazidocubanes. J. Comput. Chem. 2005, 26, 1263−1269. 30. Xu, X. J.; Xiao, H. M.; Ju, X. H.; Gong, X. D.; Zhu, W. H. Computational Studies on Polynitrohexaazaadmantanes as Potential High Energy Density Materials. J. Phys. Chem. A 2006, 110, 5929−5933. 31. Ghule, V. D.; Jadhav, P. M.; Patil, R. S.; Radhakrishnan, S.; Soman, T. QuantumChemical Studies on Hexaazaisowurtzitanes. J. Phys. Chem. A 2010, 114, 498−503. 32. Ghule, V. D.; Radhakrishnan, S.; Jadhav, P. M.; Tewari, S. P. Theoretical Studies on Nitrogen Rich Energetic Azoles. J. Mol. Model. 2011, 17, 1507−1515. 33. Politzer, P.; Murray, J. S.; Grice, M. E.; DeSalvo, M.; Miller, E. Calculation of Heats of Sublimation and Solid Phase Heats of Formation. Mol. Phys. 1997, 91, 923– 928. 34. Politzer, P.; Murray, J. S. Some Perspectives on Estimating Detonation Properties of C,H,N,O Compounds. Cent. Eur. J. Energ. Mater. 2011, 8, 209–220. 35. Politzer, P.; Lane, P.; Murray, J. S. Computational Characterization of a Potential Energetic Compound: 1,3,5,7-Tetranitro-2,4,6,8-Tetraazacubane. Cent. Eur. J. Energ. Mater. 2011, 8, 39–52. 36. Byrd, E. F. C.; Rice, B. M. Improved Prediction of Heats of Formation of Energetic Materials Using Quantum Mechanical Calculations. J. Phys. Chem. A 2006, 110, 1005−1013. 37. Politzer, P.; Murray, J. S. Computational Prediction of Condensed Phase Properties from Statistical Characterization of Molecular Surface Electrostatic Potentials. Fluid Phase Equilib. 2001, 185, 129−137. 38. Bulat, F. A.; Toro-Labbe, A.; Brinck, T.; Murray, J. S.; Politzer, P. Quantitative Analysis of Molecular Surfaces: Areas, Volumes, Electrostatic Potentials and Average Local Ionization Energies. J. Mol. Model. 2010, 16, 1679−1691. 39. Jenkins, H. D. B. Thermodynamics of the Relationship between Lattice Energy and Lattice Enthalpy. J. Chem. Educ. 2005, 82, 950-952.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 14 of 27

40. Jenkins, H. D. B.; Tudela, D.; Glasser, L. Lattice Potential Energy Estimation for Complex Ionic Salts from Density Measurements. Inorg. Chem. 2002, 41, 2364-2367. 41. Glasser, L.; Jenkins, H. D. B. Lattice Energies and Unit Cell Volumes of Complex Ionic Solids. J. Am. Chem. Soc. 2000, 122, 632-638. 42. Jenkins, H. D. B.; Roobottom, H. K.; Passmore, J.; Glasser, L. Relationships among

Ionic

Lattice

Energies,

Molecular

(Formula

Unit)

Volumes,

and

Thermochemical Radii. Inorg. Chem. 1999, 38, 3609-3620. 43. Hofmann, D. W. M. Fast Estimation of Crystal Densities. Acta Cryst. B 2002, 57, 489-493.


Page 15 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


List of Tables

Table 1. Total Energy (E0), Zero Point Energy (ZPE), and Thermal Correction (∆HT) at the B3PW91/6-31G(d,p) Level and molecular surface properties for the non-ionic triazine derivatives (I-V).

a

Compd

E0 a

ZPEb

∆HTc

Ad

σ2tote

vf

I

-948.71128

0.0890

0.0127

213.57

240.84

0.07

II

-1004.03410

0.1067

0.0154

224.31

225.89

0.14

III

-854.98139

0.1219

0.0142

208.87

238.28

0.19

IV

-963.15927

0.1079

0.0153

228.99

181.28

0.21

V

-1059.35555

0.1241

0.0166

237.74

179.52

0.13

b

c

d

Total energy (a.u.). Zero point energy (a.u.). Thermal correction (a.u.). Area of the isosurface of

0.001 electrons/bohr3 electronic density (Å2). eMeasure of variability of the electrostatic potential (kJ/mol). fDegree of balance between the positive and negative surface potentials.

Table 2. Energetic properties of non-ionic triazine derivatives (I-V). OBa

HOFGasb

HOFSubc

HOFSolidd

ρe

Df

Pg

Qh

(%)

(kJ/mol)

(kJ/mol)

(kJ/mol)

(g/cm3)

(km/s)

(GPa)

(cal/g)

I

-3.5

274.09

92.55

181.54

1.95

9.05

38.07

1432

II

-6.5

291.52

107.42

184.10

1.91

8.89

36.27

1369

III

-29.6

207.88

107.23

100.65

1.79

7.94

27.87

1082

IV

-19.8

532.80

113.50

419.30

1.89

8.52

33.13

1235

V

-9.2

312.58

108.81

203.77

1.88

8.78

35.07

1329

Compd

a

b

c

d

Oxygen balance. Gas-phase heat of formation. Heat of sublimation. Solid-phase heat of formation.

e

Density. fDetonation velocity. gDetonation pressure. hChemical energy of detonation.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 16 of 27

Table 3. Energetic properties of series A salts (1-22). Compd.

OBa

HOFcb

HOFac

UPotd

HLe

HOFsaltf

ρg

VODh

DPi

Qj

1

-12.9

634.8

-92.2

512

517

26

1.84

8.53

32.66

1249

2

-15.2

761.2

-92.2

501

506

163

1.82

8.63

33.25

1323

3

-6.1

674.2

-92.2

504

509

73

1.86

8.88

35.70

1394

4

-27.6

567.2

-92.2

484

489

-14

1.78

7.93

27.71

1073

5

-20.3

914.3

-92.2

478

483

339

1.85

8.41

31.86

1221

6

-28.9

657.7

-92.2

476

481

85

1.76

7.98

27.90

1115

7

-30.0

775.6

-92.2

468

473

210

1.75

8.09

28.55

1174

8

-31.0

894.3

-92.2

461

466

336

1.74

8.18

29.08

1227

9

-11.9

700.6

-92.2

469

474

134

1.85

8.64

33.64

1299

10

-31.2

381.6

-92.2

464

469

-180

1.77

7.65

25.70

973

11

-20.9

530.6

-92.2

478

483

-45

1.80

8.18

29.65

1146

12

-22.4

619.5

-92.2

470

475

52

1.78

8.21

29.72

1181

13

-33.0

946.9

-92.2

474

479

376

1.80

8.17

29.58

1266

14

-33.0

796.4

-92.2

474

479

225

1.80

7.97

28.21

1152

15

-33.9

753.8

-92.2

466

471

191

1.78

7.85

27.16

1090

16

-34.8

841.2

-92.2

459

464

285

1.77

7.92

27.56

1124

17

-16.2

909.5

-92.2

468

473

344

1.88

8.66

34.12

1376

18

-20.3

954.4

-92.2

478

483

379

1.85

8.45

32.21

1248

19

-21.8

1019.1

-92.2

470

475

452

1.83

8.45

31.99

1260

20

-33.9

925.2

-92.2

466

471

362

1.78

8.07

28.67

1215

21

-32.2

1324.3

-92.2

450

455

777

1.79

8.40

31.23

1355

22

-46.8

1180.6

-92.2

429

434

654

1.74

7.73

25.95

1140

a

b

Oxygen balance (%). Heat of formation of cation (kJ mol ). Heat of formation of anion (kJ mol-1).

d

-1

c

Lattice potential energy (kJ mol-1). eLattice energy (kJ mol-1). fHeat of formation of salt (kJ mol-1).

g

Density (g cm-3). hVelocity of detonation (km s-1). iDetonation pressure (GPa). jChemical energy of

detonation (cal g-1).


Page 17 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Table 4. Energetic properties of series B salts (1-22). Compd.

OBa

HOFcb

HOFac

UPotd

HLe

HOFsaltf

ρg

VODh

DPi

Qj

1

-22.9

634.8

59.9

1458

1465

-136

1.74

7.96

27.56

1045

2

-25.8

761.2

59.9

1409

1416

166

1.72

8.25

29.37

1212

3

-10.3

674.2

59.9

1422

1429

-21

1.78

8.67

33.12

1328

4

-44.0

567.2

59.9

1335

1342

-148

1.68

7.23

22.21

856

5

-30.8

914.3

59.9

1309

1316

573

1.79

8.06

28.70

1110

6

-44.7

657.7

59.9

1301

1309

66

1.66

7.41

23.14

948

7

-45.3

775.6

59.9

1271

1279

332

1.65

7.62

24.40

1057

8

-45.8

894.3

59.9

1244

1252

597

1.64

7.79

25.38

1150

9

-17.6

700.6

59.9

1276

1282

179

1.79

8.44

31.48

1247

10

-46.2

381.6

59.9

1256

1263

-440

1.68

6.96

20.59

770

11

-32.3

530.6

59.9

1310

1318

-197

1.71

7.67

25.32

994

12

-33.8

619.5

59.9

1279

1287

12

1.70

7.82

26.21

1067

13

-50.2

946.9

59.9

1294

1302

652

1.72

7.74

25.84

1188

14

-50.2

796.4

59.9

1294

1302

351

1.72

7.44

23.88

1014

15

-50.5

753.8

59.9

1265

1272

296

1.70

7.30

22.85

940

16

-50.6

841.2

59.9

1238

1246

496

1.69

7.45

23.69

1005

17

-23.6

909.5

59.9

1270

1277

602

1.84

8.51

32.52

1363

18

-30.8

954.4

59.9

1309

1316

653

1.79

8.14

29.30

1157

19

-32.3

1019.1

59.9

1278

1285

813

1.77

8.18

29.42

1189

20

-50.5

925.2

59.9

1265

1272

638

1.70

7.64

24.99

1125

21

-45.3

1324.3

59.9

1206

1213

1496

1.72

8.17

28.82

1349

22

-62.7

1180.6

59.9

1134

1142

1279

1.67

7.35

22.86

1073

a

b


d

-1

c


g





1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 18 of 27

Table 5. Energetic properties of series C salts (1-22). Compd.

OBa

HOFcb

HOFac

UPotd

HLe

HOFsaltf

ρg

VODh

DPi

Qj

1

-44.8

634.8

113.4

1480

1488

-105

1.64

7.24

21.95

868

2

-45.7

761.2

113.4

1428

1435

201

1.62

7.63

24.17

1074

3

-28.4

674.2

113.4

1442

1449

13

1.69

8.12

28.14

1202

4

-62.3

567.2

113.4

1350

1357

-109

1.60

6.61

18.02

711

5

-45.6

914.3

113.4

1322

1330

612

1.72

7.60

24.89

1006

6

-61.5

657.7

113.4

1314

1322

107

1.59

6.88

19.45

824

7

-60.9

775.6

113.4

1283

1290

375

1.58

7.15

20.89

951

8

-60.4

894.3

113.4

1255

1262

640

1.58

7.38

22.29

1059

9

-30.2

700.6

113.4

1289

1296

219

1.73

8.07

28.17

1163

10

-61.0

381.6

113.4

1267

1274

-397

1.62

6.45

17.31

651

11

-48.1

530.6

113.4

1324

1331

-156

1.64

7.17

21.55

875

12

-48.5

619.5

113.4

1292

1299

53

1.63

7.36

22.61

962

13

-66.7

946.9

113.4

1307

1314

693

1.65

7.29

22.31

1090

14

-66.7

796.4

113.4

1307

1314

392

1.65

6.95

20.30

902

15

-65.7

753.8

113.4

1276

1284

337

1.64

6.85

19.63

831

16

-64.9

841.2

113.4

1249

1256

540

1.63

7.03

20.60

908

17

-36.0

909.5

113.4

1282

1289

643

1.78

8.15

29.28

1290

18

-45.6

954.4

113.4

1322

1330

692

1.72

7.69

25.50

1055

19

-46.2

1019.1

113.4

1290

1297

855

1.70

7.76

25.77

1098

20

-65.7

925.2

113.4

1276

1284

680

1.64

7.22

21.84

1029

21

-57.6

1324.3

113.4

1215

1222

1540

1.66

7.83

25.85

1285

22

-73.7

1180.6

113.4

1141

1149

1326

1.63

7.06

20.78

1008

a

b


d

-1

c


g




Page 19 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Table 6. Energetic properties of series D salts (1-22). Compd.

OBa

HOFcb

HOFac

UPotd

HLe

HOFsaltf

ρg

VODh

DPi

Qj

1

-34.8

634.8

359.9

1459

1467

163

1.72

7.70

25.60

979

2

-36.6

761.2

359.9

1410

1417

465

1.70

8.02

27.54

1154

3

-20.8

674.2

359.9

1423

1431

277

1.77

8.48

31.59

1272

4

-53.3

567.2

359.9

1336

1343

151

1.66

7.00

20.67

802

5

-38.8

914.3

359.9

1310

1317

872

1.78

7.90

27.47

1067

6

-53.3

657.7

359.9

1302

1309

366

1.65

7.23

21.95

900

7

-53.3

775.6

359.9

1272

1279

632

1.64

7.46

23.28

1013

8

-53.3

894.3

359.9

1245

1252

897

1.63

7.64

24.32

1110

9

-24.9

700.6

359.9

1277

1285

476

1.78

8.30

30.33

1209

10

-53.8

381.6

359.9

1256

1264

-141

1.67

6.79

19.50

726

11

-40.8

530.6

359.9

1311

1319

102

1.70

7.50

24.10

947

12

-41.7

619.5

359.9

1280

1288

311

1.68

7.63

24.76

1024

13

-58.5

946.9

359.9

1295

1302

952

1.70

7.55

24.43

1145

14

-58.5

796.4

359.9

1295

1302

651

1.70

7.24

22.47

969

15

-58.2

753.8

359.9

1266

1273

595

1.69

7.14

21.77

898

16

-57.9

841.2

359.9

1239

1246

796

1.68

7.30

22.65

966

17

-30.6

909.5

359.9

1271

1278

901

1.83

8.37

31.41

1327

18

-38.8

954.4

359.9

1310

1317

952

1.78

7.98

28.07

1113

19

-39.8

1019.1

359.9

1279

1286

1112

1.76

8.03

28.25

1149

20

-58.2

925.2

359.9

1266

1273

937

1.69

7.49

23.91

1084

21

-51.7

1324.3

359.9

1206

1214

1795

1.71

8.05

27.84

1317

22

-68.1

1180.6

359.9

1135

1142

1579

1.66

7.23

22.05

1045

a

b


d

-1

c


g





1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Page 20 of 27

Table 7. Energetic properties of series E salts (1-22). Compd.

OBa

HOFcb

HOFac

UPotd

HLe

HOFsaltf

ρg

VODh

DPi

Qj

1

-30.8

634.8

502.5

2627

2637

-230

1.67

7.61

24.51

935

2

-33.6

761.2

502.5

2509

2519

267

1.65

8.07

27.39

1196

3

-13.3

674.2

502.5

2540

2550

-25

1.73

8.62

32.20

1338

4

-54.8

567.2

502.5

2339

2349

-145

1.62

6.91

19.84

787

5

-37.2

914.3

502.5

2281

2291

954

1.76

7.99

27.91

1114

6

-54.7

657.7

502.5

2265

2275

201

1.61

7.21

21.50

918

7

-54.5

775.6

502.5

2200

2210

619

1.60

7.49

23.10

1060

8

-54.5

894.3

502.5

2142

2152

1033

1.59

7.69

24.29

1177

9

-20.9

700.6

502.5

2211

2221

383

1.76

8.45

31.22

1285

10

-55.0

381.6

502.5

2167

2177

-530

1.63

6.70

18.74

723

11

-39.5

530.6

502.5

2285

2295

-201

1.66

7.51

23.77

972

12

-40.7

619.5

502.5

2217

2227

134

1.65

7.70

24.95

1070

13

-60.8

946.9

502.5

2249

2259

1084

1.67

7.59

24.38

1213

14

-60.8

796.4

502.5

2249

2259

633

1.67

7.23

22.17

1003

15

-60.2

753.8

502.5

2186

2196

568

1.65

7.10

21.19

923

16

-59.7

841.2

502.5

2130

2140

886

1.64

7.29

22.25

1007

17

-27.9

909.5

502.5

2197

2207

1024

1.82

8.53

32.47

1422

18

-37.2

954.4

502.5

2281

2291

1075

1.76

8.08

28.60

1170

19

-38.5

1019.1

502.5

2214

2224

1336

1.73

8.12

28.58

1216

20

-60.2

925.2

502.5

2186

2196

1082

1.65

7.49

23.59

1143

21

-52.4

1324.3

502.5

2062

2072

2403

1.68

8.13

28.11

1412

22

-70.7

1180.6

502.5

1917

1927

2117

1.64

7.27

22.11

1100

a

b


d

-1

c


g




Page 21 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


List of Figure Captions

Figure 1. Molecular frameworks of a series of substituted 1,3,5-triazine molecules (IV). Figure 2. Designed isodesmic reactions to calculate gas-phase heat of formation for the non-ionic compounds (I-V). Figure 3. Born-Haber cycle for the formation of energetic salts. Figure 4. Molecular structures of cations (1-22) and anions (A-E) selected for the design of energetic salts. Figure 5. Comparison of the HOFs of energetic salts of the Series A (cation:anion ratio is 1:1), Series B (cation:anion ratio is 2:1), and Series E (cation:anion ratio is 3:1). Figure 6. Comparison of the densities of the series A, B and E. Cation:anion charge ratio of the series A, B and E are 1:1, 2:1 and 3:1, respectively. Figure 7. Effect of –NO2 (series B), –NH2 (series C) and –N3 (series D) substituents on the densities of corresponding salts. Figure 8. Comparison of the detonation velocities and detonation pressures of the designed energetic salts.



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Figure 1

Figure 2


Page 22 of 27

Page 23 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


-∆HOF

Cation+ Anion- (Solid)

mC(s) + nH2(g) + oN2(g) + pO2(g)

∆HL -∆HOFanion

Cation+ (gas) + Anion- (gas)

-∆HOFcation

Figure 3

O2N N O2N

O2N

N N N

N NO2

O2N

N

N

N

O2N

N

N

A

NO2

H2N

O2N

N

N

B

N

N N

NO2

N3

C

O2N

N N

N N

N

N

NO2

O2N

N

N N

N

D

NO2

E

[Anions]

NH2 NH4

NH2NH3

NH3OH

1

2

3

N H

NO2

H2N

16

HN N N H 17

H2N

NH2

H2N

NH2 NH2

N H

H2N

H2N

N H

N H

N H

N NH N NH2 N NH2

18

19

13

H2N HN

NH2 NH

H2N

N N NH 22 [Cations]

Figure 4


N H

NH2

N NH2

N NH N NH2 N CH3

NH

N H

NH2

NH2

HN

20

N N

H2N

8

N NH NH3

12

11

N NH N NH2 N H

N H

NH2

7

O NH3

H2N

NH2

6

O

NH2

NO2

N NH

HN

5

10

NH2 N NH2

N3

NH2 N H

9

H2N

NH2 4

O

NH2 H2N

H2N

NH2

HN N

N H 14

H2N

N N H 15

N N H2NHN

NHNH3 N N 21


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Figure 5

Figure 6


Page 24 of 27

Page 25 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


Figure 7

Figure 8



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

Table of Contents (ToC)


Page 26 of 27

Page 27 of 27

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


○ 152x88mm (300 x 300 DPI)


Computational Screening of Nitrogen-Rich Energetic Salts Based on

Recommend Documents