Comprehensive End-to-End Design of Novel High Energy Density Materials: I. Synthesis and Characterization of Oxadiazole Based Heterocycles

Abstract

A methodology to design novel energetic materials by means of a holistic approach that links synthesis, experimental characterization, quantum-chemical modeling, and statistical empirical evaluation is proposed. An analysis of the revealed structure–property–function correlations in the LLM compound series (oxadiazole-based heterocyclic energetics), BNFF, BNFF-1, LLM-172, LLM-191, and LLM-192, led us to predict, obtain, and characterize a new member in the materials family, LLM-200, which exhibits attractive energetic characteristics compared to known conventional high energy density materials. While the applied strategy convincingly demonstrated feasibility of the end-to-end design of high energy density materials, there are certain limitations in parallel improvements of sensitivity and performance within a single compound.

Energetic Compounds Based on 3,4‐Bis(4‐nitramino‐ 1,2,5‐oxadiazol‐3‐yl)‐1,2,5‐furoxan (BNAFF)

“…Initially 4amino-1,2,5-oxadiazole-3-carboxamidoxime (AFCAO) was synthesized by reacting commercially available malononitrile with aqueous nitrous acid and then with 50 % aqueous hydroxylamine. AFCAO was treated with sodium nitrite in aqueous HCl to give 4-amino-1,2,5-oxadiazole-3-carbohy -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 droximoyl chloride (AFCHC) which is then reacted with Ag 2 CO 3 in THF to give BAFF [17,20,22].…”

“…BAFF was synthesized according to the known literature. [17,18,20] Dipotassium 3,4-bis(4-nitramino-1,2,5-oxadiazol-3-yl)-1,2,5-furoxan K 2 BNAFF (2) 100 % HNO 3 (9.0 mL) was placed in a round bottom flask and 3,4-bis(4-amino-1,2,5-oxadiazol-3-yl)-1,2,5-furoxan (BAFF, 4.0 g, 15.9 mmol) was added in small portions at À10 8C . The reaction was stirred for 1.5 h at the same temperature and then for 1.5 h at À5 8C.…”

“…It melts at 108-110 8C and decomposes at 292 8C, which makes the compound of special interest as a possible TNT replacement [17,19]. All these physico-chemical properties make BNFF a promising candidate to use not only as a melt-castable ingredient in detonators but also as a high performing explosive [20,21]. Replacement of the amino groups in BAFF with nitro groups to form BNFF improves the detonation parameters of the energetic material.…”

Intra‐Ring Bridging: A Strategy for Molecular Design of Highly Energetic Nitramines

“…developed a comprehensive end‐to‐ end design strategy and devised several linear and fused heterocyclic energetic compounds with a combination of different fragments, such as oxadiazole, pyrazole, triazole, and so on. [ 18‐20 ] Li et al . systematically analyzed the crystal structures and thermal properties of 60 reported EMs, and designed three bridge fragments, namely, ‐CH 2 ‐CH 2 ‐, ‐CH 2 ‐, and 2,2'‐bi(1,3,4‐oxadiazole), which were linked to two 3,5‐dinitro‐1 H ‐pyrazoles to gain the thermostable energetic molecules.…”

Theoretical Studies on Triacetonetriperoxide (Tatp) Derivatives to Improve Their Performance

“…One is to introduce nitro and difluoramino, 7,8 and the other is to use oxygen-rich skeletons. 9 TATP, with six oxygen atoms in a ring, is expected to be a promising energetic skeleton. The disadvantage of TATP is its poor sensitivity and detonation performance 10 and modifications are needed to improve TATP's performance for meeting the requirements of HEDMs in military and civilian use.…”