Preparation, crystal structure, thermal behavior, and theoretical studies of N,N′-dinitro-4, 4′-azo-bis(1,2,4-triazolone) (DNZTO)

Jiaping Zhu 1 , Shaohua Jin 1 , Yuehai Yu 1 , Li Wan 1 , Lijie Li 1 , Shusen Chen 1  and Qinghai Shu 1
  • 1 School of Materials Science and Engineering, Beijing Institute of Technology, 100081 Beijing, P.R. China
Jiaping Zhu, Shaohua Jin, Yuehai Yu, Li Wan, Lijie Li, Shusen Chen and Qinghai Shu

Abstract

N,N′-Dinitro-4,4′-azo-bis(1,2,4-triazolone) (DNZTO) is synthesized by the reaction of 4,4′-azo-bistriazolone (ZTO) with a mixture of nitric acid and acetic anhydride. The product was fully characterized by IR, NMR, matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry, and single-crystal X-ray analysis. The explosive performance including detonation pressures (P), velocities (D) of DNZTO, and heats of formation were predicted using gaussian 09 at B3LYP/6-311+G**.

1 Introduction

Desirable characteristics for new energetic materials include positive heat of formation, high density, high detonation velocity and pressure, high thermal stability, and low sensitivity toward external forces such as impact and friction [1–8]. Recently, the combination of an azo group with nitrogen-rich heteroaromatic rings has been extensively studied because the azo linkage not only desensitizes but also dramatically increases the heats of formation of high-nitrogen compounds such as 1,1′-dinitro-3,3′-azo-1,2,4-triazole [3], 5,5′-dinitro-3,3′-azo-1,2,4-triazole [4, 5], 5,5′-dinitro-1,1′-azo-tetrazole [6], and 4,4′-dinitro-3,3′-azo-furazan [7, 8] as high energy density compounds (Fig. 1).

Fig. 1:
Fig. 1:

Different types of nitrogen-rich azo nitro-compounds.

Citation: Zeitschrift für Naturforschung B 71, 3; 10.1515/znb-2015-0121

Since the generation of N2 as an end product of propulsion or explosion is highly desirable, compounds containing a backbone of directly linked nitrogen atoms are of great interest. Therefore, many molecules that consist mainly of nitrogen but incorporate heteroatoms into the structure to provide additional stability were studied, including 4,4′-azo-bis-1,2,4-triazolone (ZTO) [9–12], 1,1′-azo-bis-1,2,3-triazole (N8) [13, 14], 4,4′-azo-bis-1,2,4-triazole [15], and 1,1′-azo-bis-1,2,3,4- tetrazole (N10) [16–20] (Fig. 2).

Fig. 2:
Fig. 2:

Compounds with four-nitrogen atom chains (N4 structures).

Citation: Zeitschrift für Naturforschung B 71, 3; 10.1515/znb-2015-0121

Triazolone derivatives have received increasing attention due to their high positive heats of formation and high nitrogen content, which can be used in potential energetic materials and intermediates of preparing high-energy explosive. In this work, the synthesis of N,N′-dinitro-4,4′-azo-bis(1,2,4-triazolone) (DNZTO) by the reaction of ZTO with a mixture nitric acid and acetic anhydride is described. The theoretical performance data were calculated at the B3LYP/6-311+G** level.

2 Experimentation

2.1 General

1H, 13C NMR spectra were recorded on a 300 MHz (Bruker AVANCE 300) nuclear magnetic resonance spectrometer operating at 300.13 or 75.48 MHz, using [D6]DMSO as a locking solvent. IR spectra were recorded using KBr pellets on a Bio-Rad model 3000 FTS spectrometer. ZTO was prepared according to the literature [9–11].

2.2 Synthesis of DNZTO (Scheme 1)

Scheme 1:
Scheme 1:

The synthesis route to DNZTO.

Citation: Zeitschrift für Naturforschung B 71, 3; 10.1515/znb-2015-0121

ZTO (0.500 g, 2.55 mmol) was added slowly to a mixture of 95% nitric acid (1.52 mL, 17.13 mmol) and acetic anhydride (3.28 mL, 34.67 mmol) at 0 °C. The reaction mixture was stirred at room temperature for 1 h and poured into crushed ice. A pink solid was obtained (0.58 g, 80.0%). The final product was obtained as a white solid (0.54 g, 74.4%) recrystallized from CH3CN-H2O (v/v = 1:3). Tdecomp = 126.55 °C (onset, 5 °C min−1). – IR (KBr pellet): 3435.4, 3124.3, 3073.1, 1757.5, 1623.9, 1553.7, 1343.2, 1282.8, 1263.1, 1235.9, 1195.4, 1146.0, 1000.5, 894.4, 843.6 cm−1. – 1H NMR ([D6]DMSO): δ = 9.260 (1H, CH) ppm. – 13C NMR ([D6]DMSO): δ = 141.376 (C=O), 129.368 (C–H) ppm. – Matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry: m/z = 287.0232 [M+H]+, 309.0050 [M+H+Na]+. – Elemental analysis for C4H2N10O6 (Mr = 286.12): calcd. C 16.79, H 0.70, N 48.95; found: C 16.81, H 0.69, N 48.96%.

2.3 X-ray crystal structure determination

Crystals of DNZTO, suitable for single-crystal X-ray diffraction, were obtained by dissolving and retaining the compound in a minimum amount of CH3CN at room temperature and subsequent filtration. The crystals were found to contain one molecule of CH3CN per molecule of DNZTO. A colorless plate-like single crystal of dimensions 0.68 × 0.30 × 0.13 mm3 was mounted on a MiteGen MicroMesh using a small amount of Cargille Immersion Oil. Data were collected on a Bruker three-circle platform diffractometer equipped with a SMART APEX II CCD detector. The crystals were irradiated using graphite monochromatized MoKα radiation (λ= 0.71073). An Oxford Cobra low-temperature device was used to keep the crystals constant at T = 153(2) K during data collection. The structure was solved and refined with the aid of the programs in the shelxtl-plus suite of programs [21, 22]. The full-matrix least-squares refinement on F2 included atomic coordinates and anisotropic displacement parameters for all non-H atoms. The H atoms were included using a riding model. Table 1 summarizes important crystal structure data.

Table 1

Crystal structure data for DNZTO · Acetonitrile.

FormulaC6H5N11O6 (C4H2N10O6·C2H3N)
Mr (g mol−1)327.21
Cryst. size (mm3)0.68 × 0.30 × 0.13
Crystal systemMonoclinic
Space groupP21/n
a (Å)13.463(5)
b (Å)6.526(2)
c (Å)14.068(5)
β (deg)95.961(5)
V3)1229.32
Z4
Dcalcd (g cm−3)1.768
μ(MoKα) (cm−1)1.57
F(000) (e)664
hkl range–18→16, ±8, –19→+18
((sinθ)/λ)max−1)0.685
Refl. measured/unique/Rint10459/3292/0.0259
Param. refined209
R(F)a/wR(F2)b (all reflexions)0.0505/0.1067
GoF (F2)c0.999
Δρfin (max/min) (e Å−3)0.21/–0.25
CCDC1054257

aR(F) = ∑||Fo|–|Fc||/∑|Fo|.

bwR(F2) = [∑w(Fo2Fc2)2/∑w(Fo2)2]1/2; w = [σ2(Fo2)+(AP)2+BP]−1, where P = (Max(Fo2, 0)+2Fc2)/3.

cGoF = S = [∑w(Fo2Fc2)2/(nobsnparam)]1/2.

CCDC 1054257 contains the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre viawww.ccdc.cam.ac.uk/data_request/cif.

3 Results and discussions

3.1 Crystal structure of DNZTO· Acetonitrile

The molecular and crystal structure of DNZTO · Acetonitrile is shown in Fig. 3. Selected bond lengths, angles, and torsion angles are listed in Table 2.

Fig. 3:
Fig. 3:

Molecular structure of DNZTO (two crystallographically independent molecules) and cell plot of DNZTO · Acetonitrile.

Citation: Zeitschrift für Naturforschung B 71, 3; 10.1515/znb-2015-0121

Table 2

Selected bond lengths (Å), angles (deg), and torsion angles (deg) for DNZTO in crystals of DNZTO · Acetonitrile.a

Molecule IMolecule II
Bond lengths (Å)N(1)–C(1)1.2882(18)N(6)–C(3)1.2891(19)
C(1)–N(3)1.3836(18)C(3)–N(8)1.3826(17)
N(3)–C(2)1.3978(18)N(8)–C(4)1.3948(19)
N(2)–C(2)1.4052(18)C(4)–N(7)1.4004(18)
N(2)–N(1)1.3874(16)N(7)–N(6)1.3831(16)
C(2)–O(1)1.1947(17)C(4)–O(4)1.1990(17)
N(2)–N(5)1.3984(16)N(7)–N(10)1.4056(17)
N(5)–O(2)1.2132(16)N(10)–O(5)1.2127(16)
N(5)–O(3)1.2105(15)N(10)–O(6)1.2078(16)
N(3)–N(4)1.3770(15)N(8)–N(9)1.3748(16)
N(4)–N(4)#11.250(2)N(9)–N(9)#21.248(2)
Bond angles (deg)C(1)–N(1)–N(2)103.75(11)C(3)–N(6)–N(7)103.88(11)
N(1)–N(2)–C(2)114.77(11)N(6)–N(7)–C(4)114.68(11)
N(2)–C(2)–N(3)99.20(11)N(7)–C(4)–N(8)99.51(11)
C(2)–N(3)–C(1)110.32(11)C(4)–N(8)–C(3)110.17(11)
N(3)–C(1)–N(1)111.88(13)N(8)–C(3)–N(6)111.72(13)
N(5)–N(2)–N(1)119.18(11)N(10)–N(7)–N(6)118.96(11)
O(3)–N(5)–N(2)116.12(12)O(6)–N(10)–N(7)116.30(12)
O(2)–N(5)–N(2)115.89(11)O(5)–N(10)–N(7)115.61(12)
O(3)–N(5)–O(2)127.99(12)O(6)–N(10)–O(5)128.08(13)
O(1)–C(2)–N(3)129.60(13)O(4)–C(4)–N(8)129.44(13)
N(4)–N(3)–C(1)130.79(12)N(9)–N(8)–C(3)131.07(12)
N(4)–N(3)–C(2)118.62(11)N(9)–N(8)–C(4)118.75(11)
N(4)#1–N(4)–N(3)110.32(14)N(9)#2–N(9)–N(8)110.32(14)
Torsion angles (deg)C(1)–N(1)–N(2)–C(2)1.86(16)C(3)–N(6)–N(7)–C(4)–1.22(16)
N(1)–N(2)–C(2)–N(3)–2.73(15)N(6)–N(7)–C(4)–N(8)1.72(15)
C(2)–N(2)–N(3)–C(1)2.54(14)N(7)–C(4)–N(8)–C(3)–1.55(14)
C(2)–N(3)–C(1)–N(1)–1.72(17)C(4)–N(8)–C(3)–N(6)0.99(17)
N(3)–C(1)–N(1)–N(2)–0.05(16)N(8)–C(3)–N(6)–N(7)0.12(16)
C(1)–N(1)–N(2)–N(5)173.65(12)C(3)–N(6)–N(7)–N(10)–171.95(12)
N(1)–N(2)–N(5)–O(3)5.66(18)N(6)–N(7)–N(10)–O(5)168.54
C(2)–N(2)–N(5)–O(3)176.50(12)N(6)–N(7)–N(10)–O(6)–12.17(18)
N(5)–N(2)–C(2)–O(1)7.0(2)N(10)–N(7)–C(4)–O(4)–9.7(3)
N(4)–N(3)–C(1)–N(1)–175.41(13)N(9)–N(8)–C(3)–N(6)0.99(17)
C(2)–N(3)–N(4)–N(4)#1178.84(14)C(4)–N(8)–N(9)–N(9)#2179.72(14)
C(1)–N(3)–N(4)–N(4)#1–7.9(2)C(3)–N(8)–N(9)–N(9)#2–0.4(2)

aSymmetry operations #1 (molecule I): –x, 1–y, 1–z; #2 (molecule II): 1–x, 1–y, 1–z.

DNZTO · Acetonitrile crystallizes in the monoclinic space group P21/n with a cell volume of 1229.37 Å3 and four molecules in the unit cell. There are two crystallographically independent molecules of DNZTO each having crystallographically imposed centrosymmetry. There are only very minor differences between the independent molecules in the crystal as may be seen from the side-by-side listing of the molecular parameters in Table 2. The entire DNZTO molecules adopt a nearly planar structure with a strictly planar N4 chain (torsion angles N(3)–N(4)–N(4)#1–N(3)#1 and N(8)–N(9)–N(9)#2–N(8)#2 = 180°), and an E-configured azo bond. The five-membered rings are only tilted to a minor extent with respect to the central N4 chain as can be seen from the respective torsion angles in Table 2. The bond lengths N(4)–N(4)#1 and N(9)–N(9)#2 are 1.250(2) and 1.248(2) Å, respectively, which indicates a delocalization of the azo π bond along the N4 moiety within DNZTO [23].

As seen from Table 2, the bond lengths N(1)–C(1) (1.2882(18) Å), C(1)–N(3) (1.3836(18) Å), N(3)–C(2) (1.3978(18) Å), N(2)–C(2) (1.4052(18) Å) in molecule I, as well as the bond lengths N(6)–C(3) (1.2891(19) Å), C(3)–N(8) (1.3826(17) Å), N(8)–C(4) (1.3948(19) Å), C(4)–N(7) (1.4004(18) Å) in molecule II are between the values for isolated C–N (1.4700 Å) and C=N (1.2730 Å) bonds, while the bond lengths N(2)–N(1) (1.3874(16) Å) and N(7)–N(6) (1.3831(16) Å) are between those of isolated N–N (1.4500 Å) and N=N (1.2500 Å) bonds. Therefore, C(1), N(1), N(2), C(2), N(3) and C(3), N(6), N(7), C(4), N(8) form a largely conjugated π system.

3.2 Thermal analysis

The thermogravimetric-differential thermal analysis (TG-DTA) curve of DNZTO is carried out at the linear heating rate of 5 °C min−1 (Fig. 4). It shows that there is one exothermic peak in the decomposition process of DNZTO. The exothermic process is from 126.55 °C to 163.76 °C with the peak temperature of 149.05 °C.

Fig. 4:
Fig. 4:

TG/DTA curve of DNZTO at a heating rate of 5 °C min−1.

Citation: Zeitschrift für Naturforschung B 71, 3; 10.1515/znb-2015-0121

3.3 Theoretical studies

The molecular structure and bond critical points of DNZTO are shown in Fig. 5. The structure has been fully optimized using the density functional theory (DFT) B3LYP method with the 6-311+G** basis set, which corresponds to the minimum energy points at the obtained molecular energy hypersurface (NImag = 0).

Fig. 5:
Fig. 5:

Molecular structure and bond critical points of DNZTO.

Citation: Zeitschrift für Naturforschung B 71, 3; 10.1515/znb-2015-0121

3.4 Natural bond orbital (NBO) analysis

In order to understand various second-order interactions between the filled orbitals of one subsystem, the second-order Fock matrix was established to evaluate donor (i)–acceptor (j) interaction in the NBO analysis [24]. For each donor (i) and acceptor (j), the stabilization energy E(2) is associated with the delocalization and estimated as

E(2)=ΔEij=qiF(i,j)2/(εjεi)

where qi is the donor orbital occupancy, εjεi are diagonal elements, and F(i, j) is the off-diagonal NBO Fock matrix element. NBO analysis provides the best method for interaction among bonds and also provides a convenient basis for investigating charge transfer in molecular systems [25, 26]. The larger the E2 value, the more intensive is the donation tendency from electron donors to electron acceptors, and the greater is the extent of conjugation of the whole system [27]. Delocalization of electron density between occupied Lewis type (bond or lone pair) NBO orbitals and formally unoccupied (antibonding) non-Lewis NBO orbitals corresponds to a stabilizing donor–acceptor interaction. NBO analysis has been performed on the DNZTO molecule at the B3LYP/6-311+G(d, p) level in order to elucidate the intramolecular hybridization and delocalization of electron density within the molecule. The intramolecular hyperconjugative interactions of the BD N(1)–N(6) and BD* N(2)–C(3) orbital lead to strong stabilization energies of 4.94 kJ mol−1. The most important interaction energy in this molecule is due to electron donation from LP(N1) to the antibonding acceptors BD* N(2)–C(3), BD* C(5)–O(9), and BD* N(6)–O(10) resulting in stabilization energies of 99.79, 191.38 and 171.58 kJ mol−1, respectively. The same LP(N4) orbital with the antibonding acceptor BD* N(2)–C(3), BD* C(5)–O(9), and BD* N(8)–N(8′) leads to moderate stabilization energies of 152.58, 172.04, and 163.71 kJ mol−1, respectively. The E(2) values and types of the transitions are shown in Table 3.

Table 3

Second-order perturbation theory analysis of the Fock matrix in NBO basis for DNZTO.

Donor NBOED(i) (e)Acceptor NBOED(i) (e)E(2) (kJ mol−1)εjεi (a.u.)F(i, j) (a.u.)
BD N(1)–N(2)1.9817BD* C(3)–H(7)0.016813.771.270.058
BD N(1)–C(5)1.9856BD* N(4)–N(8)0.036214.441.170.057
BD N(1)–N(6)1.9897BD* N(2)–C(3)0.00854.941.450.037
BD N(2)–C(3)1.9784BD* N(1)–N(6)0.211317.711.070.063
BD N(2)–C(3)1.9784BD* N(4)–N(8)0.036213.771.240.057
BD C(3)–N(4)1.9898BD* C(5)–O(9)0.008712.141.480.059
BD N(4)–C(5)1.9786BD* N(1)–N(6)0.211316.830.970.059
BD N(4)–N(8)1.9835BD* N(8′)–N(4′)0.036215.611.250.061
BD C(5)–O(9)1.9934BD* N(5)–C(1)0.12047.371.460.047
BD N(8)–N(8′)1.9480BD* N(4′)–C(5′)0.11268.081.370.047
LP N(1)1.6416BD* N(2)–C(3)0.228899.790.290.077
BD* C(5)–O(9)0.3341191.380.310.106
BD* N(6)–O(10)0.6495171.580.170.081
LP N(4)1.6005BD* N(2)–C(3)0.2288152.580.290.096
BD* C(5)–O(9)0.3341172.040.310.102
BD* N(8)–N(8′)0.2719163.710.240.089

3.5 Molecular electrostatic potential

The molecular electrostatic potential (MEP) is a plot of electrostatic potential mapped on the constant electron density surface displaying the electrostatic potential distribution. The different values are represented by different colors, red representing regions of most negative electrostatic potential (preferred site for electrophilic attack), blue representing regions of most positive electrostatic potential (preferred site for nucleophilic attack), and green representing regions of zero potential. To predict reactive sites for electrophilic and nucleophilic attack for DNZTO, the MEP at the B3LYP/6-311+G(d, p) level was mapped with the total electron density of the molecule. In Fig. 6, red indicates the more electron rich and blue the more electron poor areas. Furthermore, the polarization effect is clearly visible. The color code of this map is in the range between –0.0125 and 0.0125 (red and blue). Molecular shape, size, and dipole moments of the molecule provide a visual method to understand the relative polarity [28]. As can be seen from the MEP map of the molecule, the negative region is mainly localized at the O atoms of nitro groups, whereas the positive region lies in the five-membrane aromatic ring systems.

Fig. 6:
Fig. 6:

Molecular surfaces obtained using the B3LYP/6-311+G(d, p) level of DNZTO.

Citation: Zeitschrift für Naturforschung B 71, 3; 10.1515/znb-2015-0121

3.6 Total density Alpha density MEP ESP

Contour (Total density) Contour (HOMO) Contour (LUMO) Contour (ESP) are shown in Fig. 6.

The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of DNZTO are shown in Fig. 7. The frontier orbital gap facilitates in characterizing the chemical reactivity and kinetic stability of the molecule. The red and green colors represent the positive and negative values for the wavefunction. The HOMO is the orbital that primarily acts as an electron donor and the LUMO is the orbital that mainly acts as an electron acceptor [29, 30]. The energy gap between the HOMO (–0.2970 a.u.) and the LUMO (–0.1435 a.u.) of the molecule is about 0.1535 a.u. The HOMO and LUMO energy gap explains the eventual charge transfer interactions taking place within the molecule. Mulliken [31] has derived the wavefunctions for the ground state and excited states of the complex and the charge distribution over the atoms thus produces a way of examining the proton transfer process. The charge distributions calculated by the Mulliken method [32] for the equilibrium geometry of DNZTO are given in Table 4.

Fig. 7:
Fig. 7:

HOMO (left) and LUMO (right) of DNZTO.

Citation: Zeitschrift für Naturforschung B 71, 3; 10.1515/znb-2015-0121

Table 4

Mulliken charge population of atoms in DNZTO.

AtomMulliken charge (e)Natural charge (e)
N10.7107–0.2001
N2–0.3066–0.2239
C30.13340.2234
N4–0.6335–0.3158
C50.35770.7928
N6–0.30450.6346
H70.20070.2438
N8–0.0317–0.0080
O9–0.2230–0.5178
O100.0515–0.3105
O110.0452–0.3185

3.7 Detonation performance

The theoretical parameters of DNZTO were calculated by the Kamlet-Jacobs equation [33, 34] and are presented in Table 5. Although some of the calculated values show a remarkable similarity to those of 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) [35, 36] (Table 5), especially the friction sensitivity of only 10 N as compared to 120 N for RDX rules out that DNZTO can be used as RDX replacement. This could already be seen also from the low onset of thermal decomposition of 126 °C (vide supra), the value for RDX being 210 °C.

Table 5

Theoretically predicted performance parameters of DNZTO.

Cpd.ρa (g cm−3)HOFb (kJ mol−1)Q (J g−1)D (m s−1)P (GPa)ISc (J)FSd (N)ESDe (J)Ispf (s)
DNZTO1.805593.661519.68887035.817100.235280
RDX [35, 36]1.8270.001591.03875034.907.41200.235258

aCalculated at the B3LYP/6-311+G** level (the molecular volume of each molecule was calculated according to the method given by Monte Carlo based on 0.001 e bohr−3 density space).

bCalculated heat of formation.

cImpact sensitivity (BAM drophammer).

dFriction sensitivity.

eElectrostatic sensitivity.

fSpecific impulse.

4 Conclusions

The synthesis and characterization of DNZTO are described in this study. The thermal study showed that DNZTO decomposes at 149.05 °C. In order to understand the relationship between the structure and performance of DNZTO, the stabilization energy E(2), molecular electrostatic potential, HOMO–LUMO energy gaps, and Mulliken charge distributions were calculated at the B3LYP/6-311+G** level.

Acknowledgments

We acknowledge the financial support from the Basic Research Found of Beijing Institute of Technology of China (No. 3090012211410) and the Excellent Young Scholar research Found of Beijing Institute of Technology of China (No. 3090012331542).

References

  • [1]

    V. Thottempudi, H. X. Gao, J. M. Shreeve, J. Am. Chem. Soc. 2011, 133, 6464.

  • [2]

    D. E. Chavez, B. C. Tappan, Eighth International Symposium on Special Topics in Chemical Propulsion (8-ISICP), Los Alamos National Laboratory, Los Alamos, NM, 2009.

  • [3]

    R. Sivabalan, M. Anniyappan, S. J. Pawar, M. B. Talawar, G. M. Gore, S. Venugopalan, B. R. Gandhe, J. Hazard. Mater. 2006, A37, 672.

  • [4]

    D. L. Naud, M. A. Hiskey, H. H. Harry, J. Energ. Mater. 2003, 21, 57.

  • [5]

    A. A. Dippold, T. M. Klapötke, F. A. Martin, Z. Anorg. Allg. Chem. 2011, 637, 1181.

  • [6]

    Q. H. Zhang, J. M. Shreeve, Angew. Chem. Int. Ed. 2013, 52, 8792.

  • [7]

    J. H. Zhang, J. M. Shreeve, J. Am. Chem. Soc. 2014, 136, 4437.

  • [8]

    P. Yin, D. A. Parrish, J. M. Shreeve, Chem. Eur. J. 2014, 20, 6707.

  • [9]

    C. Ma, J. Huang, H. X. Ma, K. Z. Xu, X. Q. Lv, J. R. Song, N. N. Zhao, J. Y. He, Y. S. Zhao, J. Mol. Struct. 2013, 1036, 521.

  • [10]

    Y. T. Zhong, J. Huang, J. R. Song, K. Z. Xu, D. Zhao, L. Q. Wang, X. Y. Zhang, Chin. J. Chem. 2011, 29, 1672.

  • [11]

    C. Ma, J. Huang, Y. T. Zhong, K. Z. Xu, J. R. Song, Z. Zhang, Bull. Korean Chem. Soc. 2013, 34, 2086.

  • [12]

    J. P. Zhu, S. H. Jin, Y. H. Yu, S. S. Chen, Q. H. Shu, Z. Kristallogr. NCS 2015, 230, 225.

  • [13]

    C. Qi, S. H. Li, Y. C. Li, Y. A. Wang, X. K. Chen, S. P. Pang, Mater. Chem. 2011, 21, 3221.

  • [14]

    C. Qi, S. H. Li, Y. C. Li, Y. Wang, X. X. Zhao, S. P. Pang, Chem. Eur. J. 2012, 18, 16562.

  • [15]

    W. Liu, S. H. Li, Y. C. Li, Y. Z. Yang, Y. Yu, S. P. Pang, J. Mater. Chem. A 2014, 2, 15978.

    • Crossref
    • Export Citation
  • [16]

    T. M. Klapötke, C. M. Sabate, New J. Chem. 2009, 33, 1605–1617.

  • [17]

    T. M. Klapötke, C. M. Sabate, Chem. Mater. 2008, 20, 1750.

  • [18]

    A. Hammerl, G. Holl, T. M. Klapötke, P. Mayer, H. Nöth, H. Piotrowski, M. Warchhold, Eur. J. Inorg. Chem. 2002, 2002, 834.

  • [19]

    B. C. Tappan, A. N. Ali, S. F. Son, T. B. Brill, Propellants Explos. Pyrotech. 2006, 31, 163.

  • [20]

    R. Sivabalan, M. B. Talawar, N. Senthilkumar, B. Kavitha, S. N. Asthana, J. Therm. Anal. Calorim. 2004, 78, 781.

  • [21]

    G. M. Sheldrick, shelxtl-plus (version 2008/4), Bruker Analytical X-ray Instruments Inc., Madison, WI (USA) 2008.

  • [22]

    G. M. Sheldrick, Acta Crystallogr. 2008, A64, 112.

  • [23]

    Y. C. Li, C. Qi, S. H. Li, H. J. Zhang, C. H. Sun, Y. Z. Yu, S. P. Pang, J. Am. Chem. Soc. 2010, 132, 12172.

  • [24]

    M. Szafran, A. Komasa, E. B. Adamska, J. Mol. Struct.: Theochem 2007, 827, 101.

    • Crossref
    • Export Citation
  • [25]

    C. James, A. Amal Raj, R. Rehunathan, I. Hubert Joe, V. S. Jayakumar, J. Raman Spectrosc. 2006, 379, 1381.

  • [26]

    J. N. Liu, Z. R. Chen, S. F. Yuan, J. Zhejiang Univ. Sci. 2005, 6B, 584.

  • [27]

    S. Sebastin, N. Sundaraganesan, Spectrochim. Acta A 2010, 75, 941.

  • [28]

    I. Fleming, Frontier Orbitals and Organic Chemical Reactions, John Wiley and Sons, New York, 1976.

  • [29]

    K. S. Thanthiriwatte, K. M. Nalin de Silva, J. Mol. Struct.: Theochem 2002, 617, 169.

    • Crossref
    • Export Citation
  • [30]

    P. S. Liyange, R. M. de Silva, K. M. Nalin de Silva, J. Mol. Struct.: Theochem 2003, 639, 195.

  • [31]

    R. S. Mulliken, J. Am. Chem. Soc. 1952, 74, 811.

  • [32]

    R. S. Mulliken, J. Chem. Phys. 1955, 23, 1833.

  • [33]

    T. Wei, J. Z. Wu, W. H. Zhu, C. C. Zhang, H. M. Xiao, J. Mol. Model. 2012, 18, 3467.

  • [34]

    D. E. Chavez, M. A. Hiskey, R. D. Gilardi, Org. Lett. 2004, 6, 2889.

  • [35]

    B. M. Rice, J. J. Hare, J. Phys. Chem. A 2002, 106, 1770.

  • [36]

    Y. X. Ou, J. J. Chen, The High Energy and Density Compounds, National Defense Industry Press, Beijing, 2005.

If the inline PDF is not rendering correctly, you can download the PDF file here.

  • [1]

    V. Thottempudi, H. X. Gao, J. M. Shreeve, J. Am. Chem. Soc. 2011, 133, 6464.

  • [2]

    D. E. Chavez, B. C. Tappan, Eighth International Symposium on Special Topics in Chemical Propulsion (8-ISICP), Los Alamos National Laboratory, Los Alamos, NM, 2009.

  • [3]

    R. Sivabalan, M. Anniyappan, S. J. Pawar, M. B. Talawar, G. M. Gore, S. Venugopalan, B. R. Gandhe, J. Hazard. Mater. 2006, A37, 672.

  • [4]

    D. L. Naud, M. A. Hiskey, H. H. Harry, J. Energ. Mater. 2003, 21, 57.

  • [5]

    A. A. Dippold, T. M. Klapötke, F. A. Martin, Z. Anorg. Allg. Chem. 2011, 637, 1181.

  • [6]

    Q. H. Zhang, J. M. Shreeve, Angew. Chem. Int. Ed. 2013, 52, 8792.

  • [7]

    J. H. Zhang, J. M. Shreeve, J. Am. Chem. Soc. 2014, 136, 4437.

  • [8]

    P. Yin, D. A. Parrish, J. M. Shreeve, Chem. Eur. J. 2014, 20, 6707.

  • [9]

    C. Ma, J. Huang, H. X. Ma, K. Z. Xu, X. Q. Lv, J. R. Song, N. N. Zhao, J. Y. He, Y. S. Zhao, J. Mol. Struct. 2013, 1036, 521.

  • [10]

    Y. T. Zhong, J. Huang, J. R. Song, K. Z. Xu, D. Zhao, L. Q. Wang, X. Y. Zhang, Chin. J. Chem. 2011, 29, 1672.

  • [11]

    C. Ma, J. Huang, Y. T. Zhong, K. Z. Xu, J. R. Song, Z. Zhang, Bull. Korean Chem. Soc. 2013, 34, 2086.

  • [12]

    J. P. Zhu, S. H. Jin, Y. H. Yu, S. S. Chen, Q. H. Shu, Z. Kristallogr. NCS 2015, 230, 225.

  • [13]

    C. Qi, S. H. Li, Y. C. Li, Y. A. Wang, X. K. Chen, S. P. Pang, Mater. Chem. 2011, 21, 3221.

  • [14]

    C. Qi, S. H. Li, Y. C. Li, Y. Wang, X. X. Zhao, S. P. Pang, Chem. Eur. J. 2012, 18, 16562.

  • [15]

    W. Liu, S. H. Li, Y. C. Li, Y. Z. Yang, Y. Yu, S. P. Pang, J. Mater. Chem. A 2014, 2, 15978.

    • Crossref
    • Export Citation
  • [16]

    T. M. Klapötke, C. M. Sabate, New J. Chem. 2009, 33, 1605–1617.

  • [17]

    T. M. Klapötke, C. M. Sabate, Chem. Mater. 2008, 20, 1750.

  • [18]

    A. Hammerl, G. Holl, T. M. Klapötke, P. Mayer, H. Nöth, H. Piotrowski, M. Warchhold, Eur. J. Inorg. Chem. 2002, 2002, 834.

  • [19]

    B. C. Tappan, A. N. Ali, S. F. Son, T. B. Brill, Propellants Explos. Pyrotech. 2006, 31, 163.

  • [20]

    R. Sivabalan, M. B. Talawar, N. Senthilkumar, B. Kavitha, S. N. Asthana, J. Therm. Anal. Calorim. 2004, 78, 781.

  • [21]

    G. M. Sheldrick, shelxtl-plus (version 2008/4), Bruker Analytical X-ray Instruments Inc., Madison, WI (USA) 2008.

  • [22]

    G. M. Sheldrick, Acta Crystallogr. 2008, A64, 112.

  • [23]

    Y. C. Li, C. Qi, S. H. Li, H. J. Zhang, C. H. Sun, Y. Z. Yu, S. P. Pang, J. Am. Chem. Soc. 2010, 132, 12172.

  • [24]

    M. Szafran, A. Komasa, E. B. Adamska, J. Mol. Struct.: Theochem 2007, 827, 101.

    • Crossref
    • Export Citation
  • [25]

    C. James, A. Amal Raj, R. Rehunathan, I. Hubert Joe, V. S. Jayakumar, J. Raman Spectrosc. 2006, 379, 1381.

  • [26]

    J. N. Liu, Z. R. Chen, S. F. Yuan, J. Zhejiang Univ. Sci. 2005, 6B, 584.

  • [27]

    S. Sebastin, N. Sundaraganesan, Spectrochim. Acta A 2010, 75, 941.

  • [28]

    I. Fleming, Frontier Orbitals and Organic Chemical Reactions, John Wiley and Sons, New York, 1976.

  • [29]

    K. S. Thanthiriwatte, K. M. Nalin de Silva, J. Mol. Struct.: Theochem 2002, 617, 169.

    • Crossref
    • Export Citation
  • [30]

    P. S. Liyange, R. M. de Silva, K. M. Nalin de Silva, J. Mol. Struct.: Theochem 2003, 639, 195.

  • [31]

    R. S. Mulliken, J. Am. Chem. Soc. 1952, 74, 811.

  • [32]

    R. S. Mulliken, J. Chem. Phys. 1955, 23, 1833.

  • [33]

    T. Wei, J. Z. Wu, W. H. Zhu, C. C. Zhang, H. M. Xiao, J. Mol. Model. 2012, 18, 3467.

  • [34]

    D. E. Chavez, M. A. Hiskey, R. D. Gilardi, Org. Lett. 2004, 6, 2889.

  • [35]

    B. M. Rice, J. J. Hare, J. Phys. Chem. A 2002, 106, 1770.

  • [36]

    Y. X. Ou, J. J. Chen, The High Energy and Density Compounds, National Defense Industry Press, Beijing, 2005.

FREE ACCESS

Journal + Issues

Zeitschrift für Naturforschung B is an international scientific journal which publishes original papers, microreviews, and letters from all areas of inorganic chemistry, solid state chemistry, coordination chemistry, molecular chemistry, and organic chemistry.

Search