Comparative Theoretical Studies on a Series of Novel Energetic Salts Composed of 4,8-Dihydrodifurazano[3,4-b,e]pyrazine-based Anions and Ammonium-based Cations

Abstract

4,8-Dihydrodifurazano[3,4-b,e]pyrazine (DFP) is one kind of parent compound for the synthesis of various promising difurazanopyrazine derivatives. In this paper, eleven series of energetic salts composed of 4,8-dihydrodifurazano[3,4-b,e]pyrazine-based anions and ammonium-based cations were designed. Their densities, heats of formation, energetic properties, impact sensitivity, and thermodynamics of formation were studied and compared based on density functional theory and volume-based thermodynamics method. Results show that ammonium and hydroxylammonium salts exhibit higher densities and more excellent detonation performance than guanidinium and triaminoguanidinium salts. Therein, the substitution with electron-withdrawing groups (–NO2, –CH2NF2, –CH2ONO2, –C(NO2)3, –CH2N3) contributes to enhancing the densities, heats of formation, and detonation properties of the title salts, and the substitution of –C(NO2)3 features the best performance. Incorporating N–O oxidation bond to difurazano[3,4-b,e]pyrazine anion gives a rise to the detonation performance of the title salts, while increasing their impact sensitivity meanwhile. Importantly, triaminoguanidinium 4,8-dihydrodifurazano[3,4-b,e]pyrazine (J4) has been successfully synthesized. The experimentally determined density and H50 value of J4 are 1.602 g/cm3 and higher than 112 cm, which are consistent with theoretical values, supporting the reliability of calculation methods. J4 proves to be a thermally stable and energetic explosive with decomposition peak temperature of 216.7 °C, detonation velocity 7732 m/s, and detonation pressure 25.42 GPa, respectively. These results confirm that the derivative work in furazanopyrazine compounds is an effective strategy to design and screen out potential candidates for high-performance energetic salts.

The Art of Framework Construction: Core–Shell Structured Micro-Energetic Materials

“…Micro-energetic materials whose particle sizes range between several micrometers and hundreds of micrometers are mostly engaged in propellants and large-scaled explosives. High energy and safety are the greatest concerns and have always been an inherent contradiction of energetic materials because high energy levels are mostly achieved at the expense of stability [ 3 , 4 , 5 ]. Therefore, extensive work has been done to balance the stringent requirements for power and sensitivity.…”

Structure and Thermal Properties of 2,2′-Azobis(1H-Imidazole-4,5-Dicarbonitrile)—A Promising Starting Material for a Novel Group of Energetic Compounds

“…In the last decades, we can observe an intense development of another class-aromatic heterocyclic energetics, which exhibit interesting properties suitable for many applications (e.g. : gas generants, environmentally friendly pyrotechnics) [1][2][3][4][5][6]. A distinctive group is formed by azo-bridged azoles and azines [7].…”

Synergetic Explosive Performance through Cocrystallization

“…27 It is interesting to note that 1 has an 8.9% higher density than a hypothetical physical mixture of 1:2 H 2 DFP/ hydroxylamine (2, 1.682 g cm −1 ) and a 4.0% higher density than the theoretical 1:2 DFP 2− /hydroxylammonium salt (3, 1.761 g cm −3 ). 28 The detonation properties for both these materials have been calculated and are shown in Table 1. The higher density of 1 than both 2 and 3 results in 1's significantly better detonation properties, illustrating that cocrystallization of H 2 DFP with hydroxylamine has a synergetic effect on the detonation properties of the resulting energetic material.…”

“…Heats of formation were calculated by the method of Byrd and Rice and are summarized in Table . , The detonation properties were calculated by CHEETAH thermochemical code with a pressure of 33.8 GPa and a velocity of 8.68 km s –1 , which is comparable to that of TATB . It is interesting to note that 1 has an 8.9% higher density than a hypothetical physical mixture of 1:2 H 2 DFP/hydroxylamine ( 2 , 1.682 g cm –1 ) and a 4.0% higher density than the theoretical 1:2 DFP 2– /hydroxylammonium salt ( 3 , 1.761 g cm –3 ) . The detonation properties for both these materials have been calculated and are shown in Table .…”