Peng Lian

New Correlations for Predicting Impact Sensitivities of Nitro Energetic Compounds

Some new and simple correlations have been introduced to predict impact sensitivities of various nitro energetic compounds. The correlations are based on the atomic numbers of C, H, N, O, and other amending factors, which are determined by the effect of the connective positions of groups to impact sensitivity. The predicted impact sensitivities for 196 energetic compounds are compared with the latest empirical computations presented by Keshavarz. Root mean square (rms) of deviation from experimental data is 37 cm, which is lower than that obtained from Keshavarzs computation (44 cm) [25,26].

Theoretical study on the structure and stability of [1,2,5] oxadiazolo [3,4-e] [1,2,3,4]-tetrazine-4,6-Di-N-dioxide (FTDO)

Although many 1,2,3,4-tetrazine-1,3-dioxide derivates have been synthesized, [1,2,5] oxadiazolo [3,4-e] [1,2,3,4]-tetrazine-4,6-di-N-dioxide (FTDO) is the only one with high enthalpy of formation and high detonation velocity. Whereas, its stability has not been studied. In the present work, the structure of FTDO was investigated using density functional theory (DFT) method, and its stability was calculated by potential energy surface scanning and structure interconvert thermodynamics under different temperatures. The spontaneous isomerization of FTDO and its effect on the stability of FTDO were investigated. The dissociation of FTDO to N2, N2O and furoxan fragments was studied, and the possibility of synthetic route from FTDO to TTTO was discussed.

A New Synthetic Route for 3,3′-Bis(fluorodinitromethyl)difurazanyl Ether (FOF-13) and Its Energetic Properties

A new protocol for preparation of 3,3-bis(fluorodinitromethyl)difurazanyl ether (FOF-13) was developed. It involves (i) nitration of 3,3’-bis(chlorohydroxyminomethyl)difurazanyl ether with N2O5/MeCN to give 3,3-bis(chlorodinitromethyl)difurazanyl ether (4), (ii) reduction of 4 with KI/MeOH to obtain potassium salt of 3,3’-bis(dinitromethyl)difurazanyl ether (6) and (iii) fluorination of 6 with XeF2 in anhydrous acetonitrile to form the desired FOF-13. FOF-13 was fully characterized by IR, 13C NMR, 19F NMR, and elemental analysis. FOF-13 exhibits excellent physicochemical and detonation properties, such as high density (1.91 g cm‒3), good thermal stability, reasonable impact sensitivity (14 J) and friction sensitivity (64%), high measured detonation velocity (8497 m s‒1 at 1.69 g cm‒3). Furthermore, the precursors 4 and 6 were developed for the first time.

Theoretical study of the effect of N-oxides on the performances of energetic compounds

AbstractIn order to study the effects of N-oxide on structure and performance, six categories of energetic compounds were systemically investigated. The results indicated that the C–C bonds in the rings were shortened, and the C–N bonds close to the N → O bond were elongated when N atoms was oxidized to form N → O bonds. N → O bonds can increase the densities of most categories of compounds, and the increment will increase with the number of N → O bonds. As to their detonation performances, almost all categories of compounds had an increased trend, except for some NO2-, NHNO2- and ONO2-substituted compounds. The contribution of 1,2,3,4-tetrazine and 1,2,4,5-tetrazine to performances was better than that of pyrazine and [1,2,5] oxadiazolo [3,4-b] pyrazine on the whole, and the groups, especially energetic groups, made a huge contribution to performance. When R was a NH2 or ONO2 group, all compounds had lower impact sensitivities, and thus represent candidates for novel energetic compounds. However, other than the sixth category of compounds, all compounds had higher impact sensitivities when R was a NO2 or NHNO2 group, and have little significance in application. Graphical abstractTo study the effects of N-oxide on the structure and performance of energetic compounds, and to propose theoretical guidance for the design of novel compounds, the six categories (94 species) listed in the figure were investigated systemically by density functional theory methods and some empirical formulae

Synthesis and Characterization of 3,4-bis (3-fluorodinitromethylfurazan-4-oxy)furazan

A new energetic plasticizer 3,4-bis(3-fluorodinitromethylfurazan-4-oxy)furazan (BFF) was designed and synthesized via a five-step procedure including cyano addition, diazotization, N2O5 nitration, KI reduction, and XeF2 fluorination. The compound was characterized by FT-IR spectroscopy, multinuclear NMR spectroscopy (13C and 19F), elemental analysis, differential scanning calorimetry (DSC), and thermogravimetry-derivative thermogravimetry (TG-DTG). The sensitivity toward impact was determined by standardized impact tests. Furthermore, the heat of formation was calculated with the program package Gaussian 09, and the density was measured using a gas pycnometer at room temperature. Based on the measured density (1.88 g cm−3) and the calculated heat of formation (−111.1 kJ mol−1), impressive values for the detonation parameters such as detonation velocity (8318 m s−1) and pressure (32.0 GPa) were computed using the empirical Kamlet-Jacobs equations and compared to those of hexogen (RDX) as well as the most commonly used energetic plasticizer bis(2-fluoro-2,2-diniroethyl)formal (FEFO).

Synthesis and Properties of 4, 6-Dinitrobenzotriazol-3-dinitromethyl-1-oxide

Using 4, 6-dinitrobenzotriazol-3-ium-1-oxide (DNBTO) as starting material, 4, 6-dinitrobenzotriazol-3-dinitromethyl-1-oxide (TNBTO) was firstly designed and synthesized via the reactions of metathesis, substitution and nitration-hydrolysis. The structures of all compounds were characterized by 1 H NMR, 13 C NMR, IR and element analysis. Based on the theoretical values of densities and heat of formation, the detonation parameters were calculated using Gaussian 09 program and Kamlet-Jacobs equations. Results show that the density of TNBTO is 1.81 g·cm -3 , and the heat of formation is 143.7 kJ·mol -1 , the detonation velocity and detonation pressure are 8161.2 m·s -1 and 30.2 GPa, respectively. However, thin layer chromatography shows that TNBTO easily decomposes at room temperature, indicating that its stability is relatively poor.

Synthesis and Properties of 3, 3′-Bis(trinitromethyl- ONN -azoxy)azoxyfurazan(BTNAF)

Using 3, 3′-bis(nitromethyl ONN azoxy)azoxyfurazan(BNMAF) as starting material, an excellent energetic compound 3, 3′-bis(trinitromethyl ONN azoxy)azoxyfurazan(BTNAF) was synthesized via two steps (nitration and second nitration)with a total yield of 68.7%. The thermal behavior of BTNAF was investigated by differential scanning calorimetry(DSC) for the first time (melting point: 59-61 ℃, decomposition point: 183.6 ℃, decomposition heat: 1989 J·g-1) The physicochemistry and detonation performances of 3, 3′-bis(nitromethyl ONN azoxy)azoxyfurazan(BNMAF), 3, 3′-bis(dinitromethyl ONN azoxy)azoxyfurazan(BDNAF) and BTNAF were fully analyzed and compared by Gaussian, which revealed that BDNAF (detonation velocity: 9560 m·s-1; detonation pressure: 42.40 GPa)and BTNAF (detonation velocity: 8944 m·s-3; detonation pressure: 38.48 GPa)were two promising energetic compounds with outstanding performances.